Canonical Voices

Max

Impulse

Bug hunting on iOS 6.3.1

Me and my SO recently got an old iPad2, which we were planning to use for everyday usage around the house. Meaning, having it ready to research a recipe, get information about a topic or researching things to do together.

Unfortunately though, the iOS version that it came preinstalled with was 9.3.5. On this later version of iOS there is quite a problem with the responsiveness though.
Probably due to the big alterations on the design side the iPad feels slow and has noticeable lags when switching between applications, and even when using the web browser. The argument for this was, that it never seemed that slow before, and it should not be the hardware that wore down.
So I decided to try and downgrade the iPad and compare a much older version, namely 6.3.1, to the 9.3.5 that was installed.

After doing so successfully via ITunes and an old [IPSW](https://en.wikipedia.org/wiki/IPSW) file it was clear that the assumption was correct. Being back on the old version improved the performance significantly.
This only goes as far as the web though. When visiting certain websites errors started bringing the user satisfaction back down again.

Here are a a few screenshots of some broken styling:

And some websites were still a pleasure to use, here are the BBC and RA as examples:

Reflection

This made me think to go onto my own blog and start breaking it.
Given all the modern tech that I use for this theme, I would not be surprised to find some thing not working correctly. Mostly due to the CSS Grid specification I am using for the styling.

And indeed it did not take long:
First of all the header is broken, with the navigation links appearing in a horizontal manner, instead of a vertical one.
Additionally after some scrolling the header starts covering most of the content.

Bug hunting on iOS 6.3.1
Broken Header
Bug hunting on iOS 6.3.1
Header covering content

My speculation for the first bug being the CSS Grid, while the latter one could be related to the vh and vw units I am using.

Action

Since I am now in possession of a great testing device I set out to fix this.
Setting up my development environment by changing the the address of my development server to 0.0.0.0:8000, thus exposing it my local network, and accessing it on my iPad via IP.OF.MY.LAPTOP:8000, I have a quick feedback loop to test out my ideas and refactorings.

After looking at the stylings for the header the position: fixed; top: 0; turned out to be the problem.
Since this was a problem that was not solved elegantly initially I decided to throw it out completely and instead reiterate on the website design.

Since design in general is an iterative process I will take this as a major stepping stone in finding the right one for my blog.
For now the user (so you) will have to scroll back up to the top of the page in order to navigate. Given all the advanced technology that is on this site though, and its relative simplicity I will start from scratch for the layouting. This time using old methods and then adding modern techniques on top via cascading rules.

Resume

This rather random chain on events has again taught me, and hopefully some of you that are reading this, a lesson. While I always speak up for accessibility and its importantance in our work, I wanted to write the theme for this blog, using all the latest technologies, making my developer life comfortable and the code elegant.
This hypocrisy was made obvious right now, and I will have to backtrack and rework some parts. It also comes to show that some problems stem from architectural decisions rather than a specific bug. My assumptions about what could be breaking were not too far off, but as it turns out the problem has more depth.
While the CSS is easy to refactor and well decoupled, this could have become a nightmare if the project was bigger, since I have already accumulated tech-debt and would just keep on growing it.
But as always, a mistake made now is a mistake avoided in the future.

Cover photo by Tim Goedhart on Unsplash

Read more
Max

Impulse

Bug hunting on iOS 6.3.1

Me and my SO recently got an old iPad2, which we were planning to use for everyday usage around the house. Meaning, having it ready to research a recipe, get information about a topic or researching things to do together.

Unfortunately though, the iOS version that it came preinstalled with was 9.3.5. On this later version of iOS there is quite a problem with the responsiveness though.
Probably due to the big alterations on the design side the iPad feels slow and has noticeable lags when switching between applications, and even when using the web browser. The argument for this was, that it never seemed that slow before, and it should not be the hardware that wore down.
So I decided to try and downgrade the iPad and compare a much older version, namely 6.3.1, to the 9.3.5 that was installed.

After doing so successfully via ITunes and an old [IPSW](https://en.wikipedia.org/wiki/IPSW) file it was clear that the assumption was correct. Being back on the old version improved the performance significantly.
This only goes as far as the web though. When visiting certain websites errors started bringing the user satisfaction back down again.

Here are a a few screenshots of some broken styling:

And some websites were still a pleasure to use, here are the BBC and RA as examples:

Reflection

This made me think to go onto my own blog and start breaking it.
Given all the modern tech that I use for this theme, I would not be surprised to find some thing not working correctly. Mostly due to the CSS Grid specification I am using for the styling.

And indeed it did not take long:
First of all the header is broken, with the navigation links appearing in a horizontal manner, instead of a vertical one.
Additionally after some scrolling the header starts covering most of the content.

Bug hunting on iOS 6.3.1
Broken Header
Bug hunting on iOS 6.3.1
Header covering content

My speculation for the first bug being the CSS Grid, while the latter one could be related to the vh and vw units I am using.

Action

Since I am now in possession of a great testing device I set out to fix this.
Setting up my development environment by changing the the address of my development server to 0.0.0.0:8000, thus exposing it my local network, and accessing it on my iPad via IP.OF.MY.LAPTOP:8000, I have a quick feedback loop to test out my ideas and refactorings.

After looking at the stylings for the header the position: fixed; top: 0; turned out to be the problem.
Since this was a problem that was not solved elegantly initially I decided to throw it out completely and instead reiterate on the website design.

Since design in general is an iterative process I will take this as a major stepping stone in finding the right one for my blog.
For now the user (so you) will have to scroll back up to the top of the page in order to navigate. Given all the advanced technology that is on this site though, and its relative simplicity I will start from scratch for the layouting. This time using old methods and then adding modern techniques on top via cascading rules.

Resume

This rather random chain on events has again taught me, and hopefully some of you that are reading this, a lesson. While I always speak up for accessibility and its importantance in our work, I wanted to write the theme for this blog, using all the latest technologies, making my developer life comfortable and the code elegant.
This hypocrisy was made obvious right now, and I will have to backtrack and rework some parts. It also comes to show that some problems stem from architectural decisions rather than a specific bug. My assumptions about what could be breaking were not too far off, but as it turns out the problem has more depth.
While the CSS is easy to refactor and well decoupled, this could have become a nightmare if the project was bigger, since I have already accumulated tech-debt and would just keep on growing it.
But as always, a mistake made now is a mistake avoided in the future.

Cover photo by Tim Goedhart on Unsplash

Read more
Max

Adding Comments

The landscape for software that helps in adding comments to a website is does not shine so bright. A few big closed source companies, such as Disqus or Facebook offer an API to integrate comments. The problem with these services is that they own all the data and we have no Idea what we expose the website visitor to.

While Wordpress does come with comments baked into the platform, unfortunately Ghost and others do not. This article has a good overview of the problem in Ghost and I would identify myself as the power user, that wants a good product and respects users privacy.
That which is why I kept looking for solutions before seriously considering moving away from Ghost.

Looking at the comments (This is why we do need them) from the above article is where I have found the solution that works for me => Commento.
Available on Gitlab and with pretty good setup documentation, this commenting service allows functionalities similar to Disqus while giving all the benefits of hosting the software on your own server. Of course you can also let the company host this for you, at a really reasonable price, while still being able to see the Codebase it is running on.

If you do care about your users and would like to provide the people that visit your website with privacy and no third party ADs than you should give Commento a try.

Btw, I have no connection to them whatsoever. I just really like their product and would love for others to discover it!

Updated privacy policy on this Blog

Since the commenting functionality needs to store data I have updated the Privacy Policy.

Read more
Max

Adding Comments

The landscape for software that helps in adding comments to a website is does not shine so bright. A few big closed source companies, such as Disqus or Facebook offer an API to integrate comments. The problem with these services is that they own all the data and we have no Idea what we expose the website visitor to.

While Wordpress does come with comments baked into the platform, unfortunately Ghost and others do not. This article has a good overview of the problem in Ghost and I would identify myself as the power user, that wants a good product and respects users privacy.
That which is why I kept looking for solutions before seriously considering moving away from Ghost.

Looking at the comments (This is why we do need them) from the above article is where I have found the solution that works for me => Commento.
Available on Gitlab and with pretty good setup documentation, this commenting service allows functionalities similar to Disqus while giving all the benefits of hosting the software on your own server. Of course you can also let the company host this for you, at a really reasonable price, while still being able to see the Codebase it is running on.

If you do care about your users and would like to provide the people that visit your website with privacy and no third party ADs than you should give Commento a try.

Btw, I have no connection to them whatsoever. I just really like their product and would love for others to discover it!

Updated privacy policy on this Blog

Since the commenting functionality needs to store data I have updated the Privacy Policy.

Read more
Max

Theme update

By chance I stumbled across an old device with an outdated browser and decided to go with an entirely new approach for the theme of this blog.
The motivation was support for this device, which led to reanalyzing the whole concept of only using modern techniques. An article on this will follow in the next weeks.

The new design and Codebase is much more functional and simple, focusing on content and support for the most devices possible.
While the series on creating this theme is still an interesting read into the things I tried, it is now outdated and I would not recommend following it for the actual styling.
If you are interested in setting up the build system for a theme than it is still relevant.

If you find any bugs, please contact me and I will try to get them fixed ASAP.

Read more
Max

Theme update

By chance I stumbled across an old device with an outdated browser and decided to go with an entirely new approach for the theme of this blog.
The motivation was support for this device, which led to reanalyzing the whole concept of only using modern techniques. An article on this will follow in the next weeks.

The new design and Codebase is much more functional and simple, focusing on content and support for the most devices possible.
While the series on creating this theme is still an interesting read into the things I tried, it is now outdated and I would not recommend following it for the actual styling.
If you are interested in setting up the build system for a theme than it is still relevant.

If you find any bugs, please contact me and I will try to get them fixed ASAP.

Read more
Max

Please Note that this theme is not in use anymore. See this post for more info.

Ghost theme - Part 4: Finishing the Sidebar

On mobile Layouts < 360px width the Sidebar still overflows vertically. Lets fix it and implement the features decided on in Part 3.

First a small screenshot of the problem:

Ghost theme - Part 4: Finishing the Sidebar

As you can see the Sidebar flows into the other content.
To fix this lets remove some margins and change the nav to list its items horizontally.

All done with this bit of CSS in the styles.css file since we are changing the default layout.

.sidebar {
  grid-area: Sidebar;
  display: flex;
  flex-wrap: wrap;
  max-height: var(--sidebar-height);

  & .page-title {
      margin: 0px;
  }

  & .page-description {
      margin: 0px;
  }

  & .navigation {
    & .nav {
      display: flex;
      list-style: none;
      padding: 0px;
      margin: 0px;
    }
  }
}
@media screen and (min-width: 961px) {
    .sidebar {
        position: relative;
    }
}

This has actually become quite a lot to keep in the styles.css file.
Lets extract it into components/sidebar.css and import it.

All should look good now. Except when the content doesnt wrap!
Here is a screenshot of what I mean:

Ghost theme - Part 4: Finishing the Sidebar

Everything is in a row. The fix is quite easy with flexbox. Lets just set the flex-direction to column. That should fix it. Right?

Almost. The flex-wrap: wrap from earlier now messes things up. So lets just get rid of it on the sidebar. It worked great when the direction was row but now it is wrapping at the vertical ends, which is not what we want.

Now the sidebar looks pretty nice and our layout is almost done!

The features

Lets go on to the features:

  1. when scrolling the Title disappears
  2. when scrolling the Description disappears
  3. Only the Navigation is shown and the sidebar should shrink to its size but stay at the top

With position: sticky; the last one is pretty easy to do these days.
But to hide the other two we would need to restructure the HTML of our Sidebar since the position is relative to its parent. Which means it would still go out of the screen together with it.

So the last resort here is JavaScript together with position: fixed;. In general we should not use JavaScript for styling, but for this weird case lets make an exception and add a new class to the sidebar when it scrolls out of view.
Using that class we can then use the correct styles to achieve our goal and maybe add some nice CSS Animation.

Lets code

To use JavaScript create the file assets/js/helpers/styling.js.
The gotede build tools will take care of doing all the hard work of getting it onto the page, such as using babel and concatenating the JavaScript files you create.
Just take note that imports wont work. Since this is a Theme for purely Server-side rendered pages, that is totally fine. The JavaScript should be kept to a minimum here.

It should contain the following code, which will attach a new class to the Sidebar when we scroll down and then remove this class again once we scroll to the top:

function initScrollingListener() {
  const sidebar = document.getElementsByClassName("sidebar")[0];

  function addScrollClass() {
    if (window.pageYOffset >= 0) {
      sidebar.classList.add("scrolled");
      window.removeEventListener("scroll", addScrollClass);
      window.addEventListener("scroll", removeScrollClass);
    }
  }

  function removeScrollClass() {
    if (window.pageYOffset == 0) {
      sidebar.classList.remove("scrolled");
      window.removeEventListener("scroll", removeScrollClass);
      window.addEventListener("scroll", addScrollClass);
    }
  }

  if (window.pageYOffset == 0) {
    window.addEventListener("scroll", addScrollClass);
  } else {
    addScrollClass();
  }
}

initScrollingListener();

You should have some basic understanding of programming to really understand what is happening here but here is a small breakdown:

1.  If pageYOffset is 0 we are at the top, so we add a Listener that will call our addScrollClass function once we scroll. Otherwise we are not at the top and can call that function directly.
2. addScrollClass adds the class to the Sidebar element when we are not at the top of the page and the removes the Listener for calling itself on scrolling. Then it adds the Listener that calls removeScrollClass when we scroll.
3. removeScrollClass does exactly the opposite of addScrollClass.

Here is a list of all the DOM functionalities that are used in this piece of code: window, document, getElementsByClassName, window.pageYOffset, Element.classList, addEventListener, removeEventListener

Maybe you notice that we will call one of these functions every time that we scroll. In this case it is a very small amount of code, but it still has to run on the CPU, which is why we should generally avoid these kind of hacks.

Using the new class

So lets go and implement the things that should happen when we scroll in CSS.

.sidebar {
    /* ... */
    position: fixed;
    /* ... */
    &.scrolled{
        height: calc(var(--sidebar-height) / 1.5);
        width: var(--sidebar-width);

        & .page-title {
           display: none; 
        }

        & .page-description {
           display: none; 
        }
      }

This is all we need for now.
It should be inside the .sidebar block and hides both the description and the title when the scrolled class is added.

While it is not an optimal solution, since we use JavaScript for styling, it works in this case and does not put much load on the CPU since we only add two Listeners to our Window.

An Animation

To add some spiciness to our Sidebar suddenly reducing in size, we can add a small Animation when this happens.
Lets just make a dummy one for now where the Background transitions through colors. We can fine-tune this later when we got to the real colors of the theme.

  &.scrolled {
    /*...*/
    animation: background-transition 3s;
    background-color: yellow;
    z-index: 1;
  }
  /*...*/
  
  @keyframes background-transition {
    0% {
        background-color: blue;
    }
    100% {
        background-color: yellow;
    }
  }

One more thing is left to do.
While we have a nice Sidebar for a mobile layout these rules will break the Desktop design. Since we would have to overwrite all these rules in a MediaQuery lets make it easy on us and instead wrap these inside one themselves to keep the default on the other layouts.
To do this put all the CSS we just created for the scrolled class inside @media screen and (max-width: 960px) and dont forget to wrap them inside the .sidebar class as well.

The final sidebar.css should look like this:

.sidebar {
  grid-area: Sidebar;
  display: flex;
  flex-direction: column;
  max-height: var(--sidebar-height);

  position: fixed;
  top: 0;

  & .page-title {
      margin: 0px;
  }

  & .page-description {
      margin: 0px;
  }

  & .navigation {
    & .nav {
      display: flex;
      list-style: none;
      padding: 0px;
      margin: 0px;
    }
  }
}

@media screen and (max-width: 960px) {
    .sidebar {
        &.scrolled {
            height: calc(var(--sidebar-height) / 1.5);
            width: var(--sidebar-width);
            animation: background-transition 3s;
            background-color: yellow;
            z-index: 1;

        & .page-title {
            display: none; 
        }

        & .page-description {
            display: none; 
        }
        }
    }
}

@media screen and (min-width: 961px) {
    .sidebar {
        position: relative;
    }
}

@keyframes background-transition {
    0% {
        background-color: blue;
    }
    100% {
        background-color: yellow;
    }
}

The end

Here is a GIF of the new behaviour:

Ghost theme - Part 4: Finishing the Sidebar

Caught that Image that overflows our page? A Bug, how nice. I will fix it by next time. If you somehow followed along and want to do this as well, check out the class of such and element and try to find a setting that restricts its width ;)

Otherwise it looks like we are done here from a Basic Layouting point of view.
Of course there is still much needed on the visual front, which is what we will start in Part 6, where it is going to be all about Typography and choosing a Font.

Cover: https://unsplash.com/photos/SXihyA4oEJs

Read more
Max

Please Note that this theme is not in use anymore. See this post for more info.

Ghost theme - Part 4: Finishing the Sidebar

On mobile Layouts < 360px width the Sidebar still overflows vertically. Lets fix it and implement the features decided on in Part 3.

First a small screenshot of the problem:

Ghost theme - Part 4: Finishing the Sidebar

As you can see the Sidebar flows into the other content.
To fix this lets remove some margins and change the nav to list its items horizontally.

All done with this bit of CSS in the styles.css file since we are changing the default layout.

.sidebar {
  grid-area: Sidebar;
  display: flex;
  flex-wrap: wrap;
  max-height: var(--sidebar-height);

  & .page-title {
      margin: 0px;
  }

  & .page-description {
      margin: 0px;
  }

  & .navigation {
    & .nav {
      display: flex;
      list-style: none;
      padding: 0px;
      margin: 0px;
    }
  }
}
@media screen and (min-width: 961px) {
    .sidebar {
        position: relative;
    }
}

This has actually become quite a lot to keep in the styles.css file.
Lets extract it into components/sidebar.css and import it.

All should look good now. Except when the content doesnt wrap!
Here is a screenshot of what I mean:

Ghost theme - Part 4: Finishing the Sidebar

Everything is in a row. The fix is quite easy with flexbox. Lets just set the flex-direction to column. That should fix it. Right?

Almost. The flex-wrap: wrap from earlier now messes things up. So lets just get rid of it on the sidebar. It worked great when the direction was row but now it is wrapping at the vertical ends, which is not what we want.

Now the sidebar looks pretty nice and our layout is almost done!

The features

Lets go on to the features:

  1. when scrolling the Title disappears
  2. when scrolling the Description disappears
  3. Only the Navigation is shown and the sidebar should shrink to its size but stay at the top

With position: sticky; the last one is pretty easy to do these days.
But to hide the other two we would need to restructure the HTML of our Sidebar since the position is relative to its parent. Which means it would still go out of the screen together with it.

So the last resort here is JavaScript together with position: fixed;. In general we should not use JavaScript for styling, but for this weird case lets make an exception and add a new class to the sidebar when it scrolls out of view.
Using that class we can then use the correct styles to achieve our goal and maybe add some nice CSS Animation.

Lets code

To use JavaScript create the file assets/js/helpers/styling.js.
The gotede build tools will take care of doing all the hard work of getting it onto the page, such as using babel and concatenating the JavaScript files you create.
Just take note that imports wont work. Since this is a Theme for purely Server-side rendered pages, that is totally fine. The JavaScript should be kept to a minimum here.

It should contain the following code, which will attach a new class to the Sidebar when we scroll down and then remove this class again once we scroll to the top:

function initScrollingListener() {
  const sidebar = document.getElementsByClassName("sidebar")[0];

  function addScrollClass() {
    if (window.pageYOffset >= 0) {
      sidebar.classList.add("scrolled");
      window.removeEventListener("scroll", addScrollClass);
      window.addEventListener("scroll", removeScrollClass);
    }
  }

  function removeScrollClass() {
    if (window.pageYOffset == 0) {
      sidebar.classList.remove("scrolled");
      window.removeEventListener("scroll", removeScrollClass);
      window.addEventListener("scroll", addScrollClass);
    }
  }

  if (window.pageYOffset == 0) {
    window.addEventListener("scroll", addScrollClass);
  } else {
    addScrollClass();
  }
}

initScrollingListener();

You should have some basic understanding of programming to really understand what is happening here but here is a small breakdown:

1.  If pageYOffset is 0 we are at the top, so we add a Listener that will call our addScrollClass function once we scroll. Otherwise we are not at the top and can call that function directly.
2. addScrollClass adds the class to the Sidebar element when we are not at the top of the page and the removes the Listener for calling itself on scrolling. Then it adds the Listener that calls removeScrollClass when we scroll.
3. removeScrollClass does exactly the opposite of addScrollClass.

Here is a list of all the DOM functionalities that are used in this piece of code: window, document, getElementsByClassName, window.pageYOffset, Element.classList, addEventListener, removeEventListener

Maybe you notice that we will call one of these functions every time that we scroll. In this case it is a very small amount of code, but it still has to run on the CPU, which is why we should generally avoid these kind of hacks.

Using the new class

So lets go and implement the things that should happen when we scroll in CSS.

.sidebar {
    /* ... */
    position: fixed;
    /* ... */
    &.scrolled{
        height: calc(var(--sidebar-height) / 1.5);
        width: var(--sidebar-width);

        & .page-title {
           display: none; 
        }

        & .page-description {
           display: none; 
        }
      }

This is all we need for now.
It should be inside the .sidebar block and hides both the description and the title when the scrolled class is added.

While it is not an optimal solution, since we use JavaScript for styling, it works in this case and does not put much load on the CPU since we only add two Listeners to our Window.

An Animation

To add some spiciness to our Sidebar suddenly reducing in size, we can add a small Animation when this happens.
Lets just make a dummy one for now where the Background transitions through colors. We can fine-tune this later when we got to the real colors of the theme.

  &.scrolled {
    /*...*/
    animation: background-transition 3s;
    background-color: yellow;
    z-index: 1;
  }
  /*...*/
  
  @keyframes background-transition {
    0% {
        background-color: blue;
    }
    100% {
        background-color: yellow;
    }
  }

One more thing is left to do.
While we have a nice Sidebar for a mobile layout these rules will break the Desktop design. Since we would have to overwrite all these rules in a MediaQuery lets make it easy on us and instead wrap these inside one themselves to keep the default on the other layouts.
To do this put all the CSS we just created for the scrolled class inside @media screen and (max-width: 960px) and dont forget to wrap them inside the .sidebar class as well.

The final sidebar.css should look like this:

.sidebar {
  grid-area: Sidebar;
  display: flex;
  flex-direction: column;
  max-height: var(--sidebar-height);

  position: fixed;
  top: 0;

  & .page-title {
      margin: 0px;
  }

  & .page-description {
      margin: 0px;
  }

  & .navigation {
    & .nav {
      display: flex;
      list-style: none;
      padding: 0px;
      margin: 0px;
    }
  }
}

@media screen and (max-width: 960px) {
    .sidebar {
        &.scrolled {
            height: calc(var(--sidebar-height) / 1.5);
            width: var(--sidebar-width);
            animation: background-transition 3s;
            background-color: yellow;
            z-index: 1;

        & .page-title {
            display: none; 
        }

        & .page-description {
            display: none; 
        }
        }
    }
}

@media screen and (min-width: 961px) {
    .sidebar {
        position: relative;
    }
}

@keyframes background-transition {
    0% {
        background-color: blue;
    }
    100% {
        background-color: yellow;
    }
}

The end

Here is a GIF of the new behaviour:

Ghost theme - Part 4: Finishing the Sidebar

Caught that Image that overflows our page? A Bug, how nice. I will fix it by next time. If you somehow followed along and want to do this as well, check out the class of such and element and try to find a setting that restricts its width ;)

Otherwise it looks like we are done here from a Basic Layouting point of view.
Of course there is still much needed on the visual front, which is what we will start in Part 6, where it is going to be all about Typography and choosing a Font.

Cover: https://unsplash.com/photos/SXihyA4oEJs

Read more
K. Tsakalozos

Looking at the configuration of a Kubernetes node sounds like a simple thing, yet it not so obvious.

The arguments kubelet takes come either as command line parameters or from a configuration file you pass with --config. Seems, straight forward to do a ps -ex | grep kubelet and look in the file you see after the --config parameter. Simple, right? But… are you sure you got all the arguments right? What if Kubernetes defaulted to a value you did not want? What if you do not have shell access to a node?

There is a way to query the Kubernetes API for the configuration a node is running with: api/vi/nodes/<node_name>/proxy/cofigz. Lets see this in a real deployment.

Deploy a Kubernetes Cluster

I am using the Canonical Distribution of Kubernetes (CDK) on AWS here but you can use whichever cloud and Kubernetes installation method you like.

juju bootstrap aws
juju deploy canonical-kubernetes

..and wait for the deployment to finish

watch juju status 

Change a Configuration

CDK allows for configuring both the command line arguments and the extra arguments of the config file. Here we add arguments to the config file:

juju config kubernetes-worker kubelet-extra-config='{imageGCHighThresholdPercent: 60, imageGCLowThresholdPercent: 39}'

A great question is how we got the imageGCHighThreshholdPercent literal. At the time of this writing the official upstream docs point you to the type definitions; a rather ugly approach. There is an EvictionHard property in the type definitions, however, if you look at the example of the upstream docs you see the same property is with lowercase.

Check the Configuration

We will need two shells. On the first one we will start the API proxy and on the second we will query the API. On the first shell:

juju ssh kubernetes-master/0
kubectl proxy

Now that we have the proxy at 127.0.0.1:8001 on the kubernetes-master, use a second shell to get a node name and we query the API:

juju ssh kubernetes-master/0
kubectl get no
curl -sSL "http://localhost:8001/api/v1/nodes/<node_name>/proxy/configz" | python3 -m json.tool

Here is a full run:

juju ssh kubernetes-master/0
Welcome to Ubuntu 18.04.1 LTS (GNU/Linux 4.15.0-1023-aws x86_64)
* Documentation:  https://help.ubuntu.com
* Management: https://landscape.canonical.com
* Support: https://ubuntu.com/advantage
System information as of Mon Oct 22 10:40:40 UTC 2018
System load:  0.11               Processes:              115
Usage of /: 13.7% of 15.45GB Users logged in: 1
Memory usage: 20% IP address for ens5: 172.31.0.48
Swap usage: 0% IP address for fan-252: 252.0.48.1
Get cloud support with Ubuntu Advantage Cloud Guest:
http://www.ubuntu.com/business/services/cloud
0 packages can be updated.
0 updates are security updates.
Last login: Mon Oct 22 10:38:14 2018 from 2.86.54.15
To run a command as administrator (user "root"), use "sudo <command>".
See "man sudo_root" for details.
ubuntu@ip-172-31-0-48:~$ kubectl get no
NAME STATUS ROLES AGE VERSION
ip-172-31-14-174 Ready <none> 41m v1.12.1
ip-172-31-24-80 Ready <none> 41m v1.12.1
ip-172-31-63-34 Ready <none> 41m v1.12.1
ubuntu@ip-172-31-0-48:~$ curl -sSL "http://localhost:8001/api/v1/nodes/ip-172-31-14-174/proxy/configz" | python3 -m json.tool
{
"kubeletconfig": {
"syncFrequency": "1m0s",
"fileCheckFrequency": "20s",
"httpCheckFrequency": "20s",
"address": "0.0.0.0",
"port": 10250,
"tlsCertFile": "/root/cdk/server.crt",
"tlsPrivateKeyFile": "/root/cdk/server.key",
"authentication": {
"x509": {
"clientCAFile": "/root/cdk/ca.crt"
},
"webhook": {
"enabled": true,
"cacheTTL": "2m0s"
},
"anonymous": {
"enabled": false
}
},
"authorization": {
"mode": "Webhook",
"webhook": {
"cacheAuthorizedTTL": "5m0s",
"cacheUnauthorizedTTL": "30s"
}
},
"registryPullQPS": 5,
"registryBurst": 10,
"eventRecordQPS": 5,
"eventBurst": 10,
"enableDebuggingHandlers": true,
"healthzPort": 10248,
"healthzBindAddress": "127.0.0.1",
"oomScoreAdj": -999,
"clusterDomain": "cluster.local",
"clusterDNS": [
"10.152.183.93"
],
"streamingConnectionIdleTimeout": "4h0m0s",
"nodeStatusUpdateFrequency": "10s",
"nodeLeaseDurationSeconds": 40,
"imageMinimumGCAge": "2m0s",
"imageGCHighThresholdPercent": 60,
"imageGCLowThresholdPercent": 39,
"volumeStatsAggPeriod": "1m0s",
"cgroupsPerQOS": true,
"cgroupDriver": "cgroupfs",
"cpuManagerPolicy": "none",
"cpuManagerReconcilePeriod": "10s",
"runtimeRequestTimeout": "2m0s",
"hairpinMode": "promiscuous-bridge",
"maxPods": 110,
"podPidsLimit": -1,
"resolvConf": "/run/systemd/resolve/resolv.conf",
"cpuCFSQuota": true,
"cpuCFSQuotaPeriod": "100ms",
"maxOpenFiles": 1000000,
"contentType": "application/vnd.kubernetes.protobuf",
"kubeAPIQPS": 5,
"kubeAPIBurst": 10,
"serializeImagePulls": true,
"evictionHard": {
"imagefs.available": "15%",
"memory.available": "100Mi",
"nodefs.available": "10%",
"nodefs.inodesFree": "5%"
},
"evictionPressureTransitionPeriod": "5m0s",
"enableControllerAttachDetach": true,
"makeIPTablesUtilChains": true,
"iptablesMasqueradeBit": 14,
"iptablesDropBit": 15,
"failSwapOn": false,
"containerLogMaxSize": "10Mi",
"containerLogMaxFiles": 5,
"configMapAndSecretChangeDetectionStrategy": "Watch",
"enforceNodeAllocatable": [
"pods"
]
}
}

Summing Up

There is a way to get the configuration of an online Kubernetes node through the Kubernetes API (api/v1/nodes/<node_name>/proxy/configz). This might be handy if you want to code against Kubernetes or you do not want to get into the intricacies of your particular cluster setup.

References


How to Inspect the Configuration of a Kubernetes Node was originally published in ITNEXT on Medium, where people are continuing the conversation by highlighting and responding to this story.

Read more
K. Tsakalozos

Istio almost immediately strikes you as enterprise grade software. Not so much because of the complexity it introduces, but more because of the features it adds to your service mesh. Must-have features packaged together in a coherent framework:

  • Traffic Management
  • Security Policies
  • Telemetry
  • Performance Tuning

Since microk8s positions itself as the local Kubernetes cluster developers prototype on, it is no surprise that deployment of Istio is made dead simple. Let’s start with the microk8s deployment itself:

> sudo snap install microk8s --classic

Istio deployment available with:

> microk8s.enable istio

There is a single question that we need to respond to at this point. Do we want to enforce mutual TLS authentication among sidecars? Istio places a proxy to your services so as to take control over routing, security etc. If we know we have a mixed deployment with non-Istio and Istio enabled services we would rather not enforce mutual TLS:

> microk8s.enable istio
Enabling Istio
Enabling DNS
Applying manifest
service/kube-dns created
serviceaccount/kube-dns created
configmap/kube-dns created
deployment.extensions/kube-dns created
Restarting kubelet
DNS is enabled
Enforce mutual TLS authentication (https://bit.ly/2KB4j04) between sidecars? If unsure, choose N. (y/N): y

Believe it or not we are done, Istio v1.0 services are being set up, you can check the deployment progress with:

> watch microk8s.kubectl get all --all-namespaces

We have packaged istioctl in microk8s for your convenience:

> microk8s.istioctl get all --all-namespaces
NAME KIND NAMESPACE AGE
grafana-ports-mtls-disabled Policy.authentication.istio.io.v1alpha1 istio-system 2m
DESTINATION-RULE NAME   HOST                                             SUBSETS   NAMESPACE      AGE
istio-policy istio-policy.istio-system.svc.cluster.local istio-system 3m
istio-telemetry istio-telemetry.istio-system.svc.cluster.local istio-system 3m
GATEWAY NAME                      HOSTS     NAMESPACE      AGE
istio-autogenerated-k8s-ingress * istio-system 3m

Do not get scared by the amount of services and deployments, everything is under the istio-system namespace. We are ready to start exploring!

Demo Time!

Istio needs to inject sidecars to the pods of your deployment. In microk8s auto-injection is supported so the only thing you have to label the namespace you will be using with istion-injection=enabled:

> microk8s.kubectl label namespace default istio-injection=enabled

Let’s now grab the bookinfo example from the v1.0 Istio release and apply it:

> wget https://raw.githubusercontent.com/istio/istio/release-1.0/samples/bookinfo/platform/kube/bookinfo.yaml
> microk8s.kubectl create -f bookinfo.yaml

The following services should be available soon:

> microk8s.kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) details ClusterIP 10.152.183.33 <none> 9080/TCP kubernetes ClusterIP 10.152.183.1 <none> 443/TCP productpage ClusterIP 10.152.183.59 <none> 9080/TCP ratings ClusterIP 10.152.183.124 <none> 9080/TCP reviews ClusterIP 10.152.183.9 <none> 9080/TCP

We can reach the services using the ClusterIP they have; we can for example get to the productpage in the above example by pointing our browser to 10.152.183.59:9080. But let’s play by the rules and follow the official instructions on exposing the services via NodePort:

> wget https://raw.githubusercontent.com/istio/istio/release-1.0/samples/bookinfo/networking/bookinfo-gateway.yaml
> microk8s.kubectl create -f bookinfo-gateway.yaml

To get to the productpage through ingress we shamelessly copy the example instructions:

> microk8s.kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.spec.ports[?(@.name=="http2")].nodePort}'
31380

And our node is the localhost so we can point our browser to http://localhost:31380/productpage

Show me some graphs!

Of course graphs look nice in a blog post, so here you go.

The Grafana Service

You will need to grab the ClusterIP of the Grafana service:

microk8s.kubectl -n istio-system get svc grafana

Prometheus is also available in the same way.

microk8s.kubectl -n istio-system get svc prometheus
The Prometheus Service

And for traces you will need to look at the jaeger-query.

microk8s.kubectl -n istio-system get service/jaeger-query
The Jaeger Service

The servicegraph endpoint is available with:

microk8s.kubectl -n istio-system get svc servicegraph
The ServiceGraph

I should stop here. Go and checkout the Istio documentation for more details on how to take advantage of what Istio is offering.

What to keep from this post

References


Microk8s puts up its Istio and sails away was originally published in ITNEXT on Medium, where people are continuing the conversation by highlighting and responding to this story.

Read more
Colin Ian King

Static Analysis Trends on Linux Next

I've been running static analysis using CoverityScan on linux-next for 2 years with the aim to find bugs (and try to fix some) before they are merged into Linux.  I have also been gathering the defect count data and tracking the defect trends:

As one can see from above, CoverityScan has found a considerable amount of defects and these are being steadily fixed by the Linux developer community.  The encouraging fact is that the outstanding issues are reducing over time. Some of the spikes in the data are because of changes in the analysis that I'm running (e.g. getting more coverage), but even so, one can see a definite trend downwards in the total defects in the Kernel.

With static analysis, some of these reported defects are false positives or corner cases that are in fact impossible to occur in real life and I am slowly working through these and annotating them so they don't get reported in the defect count.

It must be also noted that over these two years the kernel has grown from around 14.6 million to 17.1 million lines of code so the defect count has dropped from 1 defect in every ~2100 lines to 1 defect in every ~3000 lines over the past 2 years.  All in all, it is a remarkable improvement for such a large and complex codebase that is growing in size at such rate.

Read more
Max

CSS Modules: the correct code split

There is a lot of talk going on in the JavaScript Frontend Community about using CSSinJS. One example for this are styled-components.
A use of them is explained over at https://www.toptal.com/javascript/styled-components-library .
In this Article I want to name an alternative and talk about some benefits.

What are CSS modules?

According to the css-modules github repo:

A CSS Module is a CSS file in which all class names and animation names are scoped locally by default.

For use in React or Vue f.e. this would mean:
All of the styles inside of a CSS Module will not affect anything else than the Component on which they are imported in.

Using CSS modules

Lets try this out with a a bit of React.
First we write a Box Component like this:

import React from 'react';
import styles from './Box.css';

const Box = () => <div />;

export default Box;

And apply some styles to it:

import React from 'react';
import styles from './Box.css';

const Box = () => <div className={styles.box} />;

export default Box;

Notice how we just import some CSS file into our JavaScript. This is where the magic happens.
In this case the CSS modularization happens through the webpack css-loader.

This is the Box.css file that gets imported.

.box {
    width: 400px;
    height: 300px;
    border-bottom: solid brown 4px;
    border-right: solid brown 4px;
    border-left: solid brown 4px;
}

we can check out the browser to see what the result looks like.

CSS Modules: the correct code split

Notice the class name? This is how CSS Modules achieve the local scoping. The imported class will be added on the correct Components and in the process their names will be changed and a unique hash added.
This will prevent any collisions with rules of other components.

No collision

Lets try this out in the browser.
Here are 2 components that use the same class name in their CSS:

Banana Component

import React from 'react';
import styles from './Banana.css';

const Banana = () => (
  <div className={styles.container}>
    <p className={styles.text}>Banana</p>
  </div>
);

export default Banana;
.container {
    display: flex;
    justify-content: center;
    align-items: center;
    border: solid 1px yellow;
}

.text {
    color: yellow;
}

Apple Component

import React from 'react';
import styles from './Apple.css';

const Apple = () => (
  <div className={styles.container}>
    <p className={styles.text}>Apple</p>
  </div>
);

export default Apple;
.container {
    display: flex;
    justify-content: center;
    align-items: center;
    border: solid 1px green;
}

.text {
    color: green;
}

Both of the components use the same classes inside of them. If we would write normal CSS this should lead to collisions, meaning that one set of rules would overwrite the other.
But checking the website again we can see that everything is normal.
Take note of the hashed class names again.

CSS Modules: the correct code split

All collisions are avoided by making the class names unique. Similar to techniques such as BEM, just in an automated way.

Conclusion

This was a very brief introduction to CSS Modules but should give a good understanding of what they do and how they work.
Some of the features are similar to techniques such as styled-components, but by being just CSS files we can benefit from some advantages.
Lets dive into the Pros and Cons to wrap it up:

Pros

  • Designers do not need to learn new ways of writing CSS in JS. Instead they can easily make changes to the correct CSS files. This way of styling, combined with mental models such a atomic design, can increase communication between Developers and Designers and development speed.
  • Separation of Concerns: We hear this all the time in Web Development and it was regarded as best practice for a long time. Given JSXs popularity one might argue that this is not true anymore, but we should still aim for it.
  • Tools and Preprocessors such as PostCss can be easily integrated to allow CSS Imports, Custom Properties etc.

Cons

  • The build task might be complicated to set up at first
  • Global styles have to be wrapped in a special :global block. Where would such a block belong?
  • The power of JavaScript is not available inside the CSS files

Cover Image is from https://unsplash.com/photos/8EzNkvLQosk

Read more
Max

CSS Modules: the correct code split

There is a lot of talk going on in the JavaScript Frontend Community about using CSSinJS. One example for this are styled-components.
A use of them is explained over at https://www.toptal.com/javascript/styled-components-library .
In this Article I want to name an alternative and talk about some benefits.

What are CSS modules?

According to the css-modules github repo:

A CSS Module is a CSS file in which all class names and animation names are scoped locally by default.

For use in React or Vue f.e. this would mean:
All of the styles inside of a CSS Module will not affect anything else than the Component on which they are imported in.

Using CSS modules

Lets try this out with a a bit of React.
First we write a Box Component like this:

import React from 'react';
import styles from './Box.css';

const Box = () => <div />;

export default Box;

And apply some styles to it:

import React from 'react';
import styles from './Box.css';

const Box = () => <div className={styles.box} />;

export default Box;

Notice how we just import some CSS file into our JavaScript. This is where the magic happens.
In this case the CSS modularization happens through the webpack css-loader.

This is the Box.css file that gets imported.

.box {
    width: 400px;
    height: 300px;
    border-bottom: solid brown 4px;
    border-right: solid brown 4px;
    border-left: solid brown 4px;
}

we can check out the browser to see what the result looks like.

CSS Modules: the correct code split

Notice the class name? This is how CSS Modules achieve the local scoping. The imported class will be added on the correct Components and in the process their names will be changed and a unique hash added.
This will prevent any collisions with rules of other components.

No collision

Lets try this out in the browser.
Here are 2 components that use the same class name in their CSS:

Banana Component

import React from 'react';
import styles from './Banana.css';

const Banana = () => (
  <div className={styles.container}>
    <p className={styles.text}>Banana</p>
  </div>
);

export default Banana;
.container {
    display: flex;
    justify-content: center;
    align-items: center;
    border: solid 1px yellow;
}

.text {
    color: yellow;
}

Apple Component

import React from 'react';
import styles from './Apple.css';

const Apple = () => (
  <div className={styles.container}>
    <p className={styles.text}>Apple</p>
  </div>
);

export default Apple;
.container {
    display: flex;
    justify-content: center;
    align-items: center;
    border: solid 1px green;
}

.text {
    color: green;
}

Both of the components use the same classes inside of them. If we would write normal CSS this should lead to collisions, meaning that one set of rules would overwrite the other.
But checking the website again we can see that everything is normal.
Take note of the hashed class names again.

CSS Modules: the correct code split

All collisions are avoided by making the class names unique. Similar to techniques such as BEM, just in an automated way.

Conclusion

This was a very brief introduction to CSS Modules but should give a good understanding of what they do and how they work.
Some of the features are similar to techniques such as styled-components, but by being just CSS files we can benefit from some advantages.
Lets dive into the Pros and Cons to wrap it up:

Pros

  • Designers do not need to learn new ways of writing CSS in JS. Instead they can easily make changes to the correct CSS files. This way of styling, combined with mental models such a atomic design, can increase communication between Developers and Designers and development speed.
  • Separation of Concerns: We hear this all the time in Web Development and it was regarded as best practice for a long time. Given JSXs popularity one might argue that this is not true anymore, but we should still aim for it.
  • Tools and Preprocessors such as PostCss can be easily integrated to allow CSS Imports, Custom Properties etc.

Cons

  • The build task might be complicated to set up at first
  • Global styles have to be wrapped in a special :global block. Where would such a block belong?
  • The power of JavaScript is not available inside the CSS files

Cover Image is from https://unsplash.com/photos/8EzNkvLQosk

Read more
Max

Please Note that this theme is not in use anymore. See this post for more info.

Ghost theme - Part 3: Mobile Layout

Here is the third part of this series where we will dive into creating the proper layout for the posts on the front page and figure out a way to display our layout on mobilephones.

Just in case lets bring up the inital sketch again

Ghost theme - Part 3: Mobile Layout

But before we can jump in and take care of the posts we have a small problem.
Using the mobile page preview of the browser we can easily spot it.

Ghost theme - Part 3: Mobile Layout

The content inside the sidebar does not fit inside the container anymore. Unfortunately max-width does not help here, as the words are actually too long and the browser cant wrap the text to the next line.

So its time to come up with a new sketch:

Ghost theme - Part 3: Mobile Layout

You have probably encountered this technique before. Here is a break down:

  1. We will make the sidebar go to the top on mobile devices.
  2. The Title and subtitle will scroll out of the screen
  3. The navigation elements will stay on top

Implementation

Responsiveness

The first thing I am going to do is to convert the whole layout to this idea.
This 'old' design will be wrapped via media-queries that activate when a certain screen-size is reached.
This way of doing it is called mobile first.
Since this theme is in an early stage of development it is still easily possible to switch to this approach.

This is the updated CSS:

variables.css

:root {
  /* Container sizes */
  --main-width: 100vw;
  --main-height: 80vh;

  --sidebar-width: 100vw;
  --sidebar-height: 20vh;
}

@media screen and (min-width: 961px) {
  :root {
    /* Container sizes */
    --main-width: 80vw;
    --main-height: 100%;

    --sidebar-width: 20vw;
    --sidebar-height: 100vh;
  }
}

styles.css

@import "./helpers/variables.css";

/* Mobile */
body {
  margin: 0px;
}

.grid-container {
  display: grid;
  height: 100%;
  grid-template-columns: 1fr;
  grid-template-rows: var(--sidebar-height) var(--main-height);
  grid-gap: 0px;
  grid-template-areas: "Sidebar" "Content";
}

.main {
  grid-area: Content;
  max-width: var(--main-width);
}

.sidebar {
  grid-area: Sidebar;
}


/* Desktop */
@media screen and (min-width: 961px) {
  .grid-container {
    display: grid;
    height: 100%;
    grid-template-columns: var(--sidebar-width) var(--main-width);
    grid-template-rows: 1fr;
    grid-gap: 0px;
    grid-template-areas: "Sidebar Content";
  }
  .main {
    grid-area: Content;
    max-width: var(--main-width);
  }
}

Et voila, we have a responsive page.

Mobile:
Ghost theme - Part 3: Mobile Layout

Desktop:
Ghost theme - Part 3: Mobile Layout

The Sidebar

As you can see the content of the Sidebar seems to escape into regions it shouldnt.

To fix this lets first change the default.hbs and remove the <div class="sidebar> and attach that class directly to the <header>.

Back in the styles.css we can now add some rules.
I am going to go for a flexbox solution.

 .sidebar {
  grid-area: Sidebar;
  display: flex;
  flex-wrap: wrap;
  max-height: var(--sidebar-height);
}
  1. Tell the component that its display type is flexbox.
  2. Make sure that the content will wrap when it reaches the bounds of this container
  3. Set a maximum height on the sidebar. To make sure it doesnt grow beyond what we would like to have in our design. This is espacially useful when the sidebar is actually at the side.

Lets leave the additional requirements of hiding the title and subtitle for the next post.

The posts

Lastly its time to implement the post layout.
On the mobile front everything looks good already. One post per row.

For the desktop we need to find a way to display 2 posts next to each other though.

First I will create a new file components/index.css that will hold all the styles for the Index page. All the styling until now was for the default.hbs.
Also do not forget to import this file in the styles.css via @import "./components/index.css";.

Here is the CSS that will accomplish the task:

.index__posts {
  display: flex;
  flex-wrap: wrap;

  & .post {
    width: var(--post-width);
  }
}

You can see that the .post class is nested inside the .index__posts class. This again is taken care of during the build step via postcss-preset-env.

The --post-width variable is inside the variables.css file and looks like this:

/* .... */
:root {
  --post-width: var(--main-width);
}

@media screen and (min-width: 961px) {
  :root {
    /* .... */
    --post-width: calc(var(--main-width) / 2);
  }

This works in the following way:

  1. When the Screen is 961px wide or bigger every post will have the width of half the --main-width.
  2. Posts are inside a flexbox container
  3. Since the flexbox container does not wrap by default and instead rezises our posts to fit inside of it, we tell it to wrap the content.
  4. 2 posts will be shown per 'row' :)

The one thing I have not mentioned until now is the CSS calc function, which allows us to dynamically calculate some values.

Wrap up

Phew, this post had quite a lot of content and advanced techniques. Nevertheless the theme is now in a good state with relatively little CSS and should be pretty maintainable and extendable.

The neat little trick with the custom-properties is something that I have added to postcss-custom-properties while writing this, so it might not yet be released. I will update this post once it is.

Here is a final image of the Desktop page, looks pretty good already :

Ghost theme - Part 3: Mobile Layout

Next post

Whats going to happen in part 4?
Lets fix the Sidebar for mobile layouts. Afterwards in part 5 the Basics should be done to start with Typography and Colours :)

Cover: https://unsplash.com/photos/-1_RZL8BGBM

Read more
Max

Please Note that this theme is not in use anymore. See this post for more info.

Here is the third part of this series where we will dive into creating the proper layout for the posts on the front page and figure out a way to display our layout on mobilephones.

Just in case lets bring up the inital sketch again

Sketch_theme-2

But before we can jump in and take care of the posts we have a small problem.
Using the mobile page preview of the browser we can easily spot it.

mobile_view_broken

The content inside the sidebar does not fit inside the container anymore. Unfortunately max-width does not help here, as the words are actually too long and the browser cant wrap the text to the next line.

So its time to come up with a new sketch:

mobile_sketch-1

You have probably encountered this technique before. Here is a break down:

  1. We will make the sidebar go to the top on mobile devices.
  2. The Title and subtitle will scroll out of the screen
  3. The navigation elements will stay on top

Implementation

Responsiveness

The first thing I am going to do is to convert the whole layout to this idea.
This 'old' design will be wrapped via media-queries that activate when a certain screen-size is reached.
This way of doing it is called mobile first.
Since this theme is in an early stage of development it is still easily possible to switch to this approach.

This is the updated CSS:

variables.css

:root {
  /* Container sizes */
  --main-width: 100vw;
  --main-height: 80vh;

  --sidebar-width: 100vw;
  --sidebar-height: 20vh;
}

@media screen and (min-width: 961px) {
  :root {
    /* Container sizes */
    --main-width: 80vw;
    --main-height: 100%;

    --sidebar-width: 20vw;
    --sidebar-height: 100vh;
  }
}

styles.css

@import "./helpers/variables.css";

/* Mobile */
body {
  margin: 0px;
}

.grid-container {
  display: grid;
  height: 100%;
  grid-template-columns: 1fr;
  grid-template-rows: var(--sidebar-height) var(--main-height);
  grid-gap: 0px;
  grid-template-areas: "Sidebar" "Content";
}

.main {
  grid-area: Content;
  max-width: var(--main-width);
}

.sidebar {
  grid-area: Sidebar;
}


/* Desktop */
@media screen and (min-width: 961px) {
  .grid-container {
    display: grid;
    height: 100%;
    grid-template-columns: var(--sidebar-width) var(--main-width);
    grid-template-rows: 1fr;
    grid-gap: 0px;
    grid-template-areas: "Sidebar Content";
  }
  .main {
    grid-area: Content;
    max-width: var(--main-width);
  }
}

Et voila, we  have a responsive page.

mobile_resp
desktop_resp

The Sidebar

As you can see the content of the Sidebar seems to escape into regions it shouldnt.

To fix this lets first change the default.hbs and remove the <div class="sidebar> and attach that class directly to the <header>.

Back in the styles.css we can now add some rules.
I am going to go for a flexbox solution.

 .sidebar {
  grid-area: Sidebar;
  display: flex;
  flex-wrap: wrap;
  max-height: var(--sidebar-height);
}
  1. Tell the component that its display type is flexbox.
  2. Make sure that the content will wrap when it reaches the bounds of this container
  3. Set a maximum height on the sidebar. To make sure it doesnt grow beyond what we would like to have in our design. This is espacially useful when the sidebar is actually at the side.

Lets leave the additional requirements of hiding the title and subtitle for the next post.

The posts

Lastly its time to implement the post layout.
On the mobile front everything looks good already. One post per row.

For the desktop we need to find a way to display 2 posts next to each other though.

First I will create a new file  components/index.css that will hold all the styles for the Index page. All the styling until now was for the default.hbs.
Also do not forget to import this file in the styles.css via @import "./components/index.css";.

Here is the CSS that will accomplish the task:

.index__posts {
  display: flex;
  flex-wrap: wrap;

  & .post {
    width: var(--post-width);
  }
}

You can see that the .post class is nested inside the .index__posts class. This again is taken care of during the build step via postcss-preset-env.

The --post-width variable is inside the variables.css file and looks like this:

/* .... */
:root {
  --post-width: var(--main-width);
}

@media screen and (min-width: 961px) {
  :root {
    /* .... */
    --post-width: calc(var(--main-width) / 2);
  }

This works in the following way:

  1. When the Screen is 961px wide or bigger every post will have the width of half the --main-width.
  2. Posts are inside a flexbox container
  3. Since the flexbox container does not wrap by default and instead rezises our posts to fit inside of it, we tell it to wrap the content.
  4. 2 posts will be shown per 'row' :)

The one thing I have not mentioned until now is the CSS calc function, which allows us to dynamically calculate some values.

Wrap up

Phew, this post had quite a lot of content and advanced techniques. Nevertheless the theme is now in a good state with relatively little CSS and should be pretty maintainable and extendable.

The neat little trick with the custom-properties is something that I have added to postcss-custom-properties while writing this, so it might not yet be released. I will update this post once it is.

Here is a final image of the Desktop page, looks pretty good already :

desktop_done

Next post

Whats going to happen in part 4?
Lets fix the Sidebar for mobile layouts. Afterwards in part 5 the Basics should be done to start with Typography and Colours :)

Read more
Max

Please Note that this theme is not in use anymore. See this post for more info.

Ghost theme - Part 2: a Grid

In this post I want to start with the styling.
the first thing here is to consult the sketches again.

Ghost theme - Part 2: a Grid

Since we split out the sidebar into the default layout, we should create a Grid for this first.
The technology I am going to use here is CSS-Grid.

The only to be aware of is the browser support. Check caniuse.com to see if it supports the browsers you want.
Since this is my personal blog and the audience is probably using modern browsers (this is an assumption, as I have no tracking yet) I am totally fine with ignoring older and more exotic browsers for now.

Grid

With tools like https://www.layoutit.com/grid we can quickly generate a basic layout.

The generated code for the grid I want on the blog according to the sketches looks like this

.grid-container {
  display: grid;
  height: 100%;
  grid-template-columns: 20vw 80vw;
  grid-template-rows: 1fr;
  grid-gap: 0px;
  grid-template-areas: "Sidebar Content";
}

.main{ grid-area: Content; }

.sidebar { grid-area: Sidebar; }

This will have to go into a css file at assets/css/styles.css in the theme folder.

Make sure to restart the `npm run start` task, so that gulp can pick up on the newly created `.css` file. Unfortunately this is not detected automatically.

In the default.hbs this stylesheet now needs to be imported and the correct classes need to be added to the HTML in the like following:


<head>
...
<link rel="stylesheet" type="text/css" href="{{asset "built/styles.css"}}" />

</head>

<body class="{{body_class}} grid-container">
    <div class="sidebar">
        <header>
            <h1 class="page-title">{{@blog.title}}</h1>
            <h2 class="page-description">{{@blog.description}}</h2>
            <nav class="navigation">
                {{navigation}}
            </nav>
        </header>
    </div>
    <div class="main">
        {{{body}}}
    </div>
    {{ghost_foot}}
</body>

The <body> is acting as the Grid container, and the sidebar and main where already equipped with the correct classes.

With this simple addition the page already looks like this:

Ghost theme - Part 2: a Grid

Variables

Now we have a good base to start introducing variables in CSS.
We can use these due to the postcss-custom-properties that are included in the default gotede gulp task.

What this will allow us is to define certain variables that should be applied throughout our app and then reuse them whenever needed.

By doing this we introduce 2 benefits.

  1. We can easily make a change in 1 place that will be applied everywhere that value was used
  2. There is 1 place to check in order to find out what specific values are

The place to define those is f.e. assets/css/helpers/variables.css, so lets create some, that we can use for our grid.

:root {
  /* Container sizes */
  --main-width: 80vw;
  --sidebar-width: 20vw;

  /* Gutter sizes */
  --gutter-horizontal--small: 2vw;
}

Notice that they are wrapped in the :root{} block.

Once this is done the gulp task will automatically make those 'available' in all our CSS files (This is actually done in the build step, but thats semantics I guess).

Lets import them and use them for the grid like this:


@import "./helpers/variables.css";


.grid-container {
  display: grid;
  height: 100%;
  grid-template-columns: var(--sidebar-width) var(--main-width);
  grid-template-rows: 1fr;
  grid-gap: 0px;
  grid-template-areas: "Sidebar Content";
}

.main {
  grid-area: Content;
}

.sidebar {
  grid-area: Sidebar;
}

You can see that the variables are used with var(VARIABLE_NAME). While this might not seem super important or useful right now, be sure that this will save a lot of headaches down the line.

A break in the layout

There is a little weirdness going on when we head over to the Writing posts with Ghost for example.
You can see that something is breaking on mobile devices. The content seems to escape the website.
Ghost theme - Part 2: a Grid

To fix this lets set a max-width on the main container. This does exactly what the name implies, telling it that its maximum width should be of some value.
Which one is the correct value? Given our Layout it should be the --main-width variable. Already comming in handy :).

Lets add it to the .main block

.main {
  grid-area: Content;
  max-width: var(--main-width);
}

Check out the post again. All good?
Nope, looks like the picture is still escaping to the right.

If you inspect the HTML you can find the picture class .kg-image. For this class we will add a rule of max-width: 100%; for now, until we encounter the styling of the pictures again, later on.

Now it looks good again:
Ghost theme - Part 2: a Grid

By the way, you can ignore the purple lines.
These are added by the Firefox developer tools. You can read about these here if you would like to use them too.

A small task for you

Check out the Publishing options article. On this page you should encounter another problem of content escaping.
I will leave this as a small task for you to fix right now. Should you need help or a hint feel free to drop me a short email or contact me on my new twitter.

What next?

The theme already looks quite a bit like the sketch. One thing we need to ensure though, is that there are always only 2 posts next to each other (and maybe alter this idea for mobile devices?).

So the next post will be focussing on those 2 topics including media-queries and flexbox.

Cover: https://unsplash.com/photos/Vwf8q3RzBRE

Read more
Max

Please Note that this theme is not in use anymore. See this post for more info.

Ghost theme - Part 2: a Grid

In this post I want to start with the styling.
the first thing here is to consult the sketches again.

Ghost theme - Part 2: a Grid

Since we split out the sidebar into the default layout, we should create a Grid for this first.
The technology I am going to use here is CSS-Grid.

The only to be aware of is the browser support. Check caniuse.com to see if it supports the browsers you want.
Since this is my personal blog and the audience is probably using modern browsers (this is an assumption, as I have no tracking yet) I am totally fine with ignoring older and more exotic browsers for now.

Grid

With tools like https://www.layoutit.com/grid we can quickly generate a basic layout.

The generated code for the grid I want on the blog according to the sketches looks like this

.grid-container {
  display: grid;
  height: 100%;
  grid-template-columns: 20vw 80vw;
  grid-template-rows: 1fr;
  grid-gap: 0px;
  grid-template-areas: "Sidebar Content";
}

.main{ grid-area: Content; }

.sidebar { grid-area: Sidebar; }

This will have to go into a css file at assets/css/styles.css in the theme folder.

Make sure to restart the `npm run start` task, so that gulp can pick up on the newly created `.css` file. Unfortunately this is not detected automatically.

In the default.hbs this stylesheet now needs to be imported and the correct classes need to be added to the HTML in the  like following:


<head>
...
<link rel="stylesheet" type="text/css" href="{{asset "built/styles.css"}}" />

</head>

<body class="{{body_class}} grid-container">
    <div class="sidebar">
        <header>
            <h1 class="page-title">{{@blog.title}}</h1>
            <h2 class="page-description">{{@blog.description}}</h2>
            <nav class="navigation">
                {{navigation}}
            </nav>
        </header>
    </div>
    <div class="main">
        {{{body}}}
    </div>
    {{ghost_foot}}
</body>

The <body> is acting as the Grid container, and the sidebar and main where already equipped with the correct classes.

With this simple addition the page already looks like this:

Ghost theme - Part 2: a Grid

Variables

Now we have a good base to start introducing variables in CSS.
We can use these due to the postcss-custom-properties that are included in the default gotede gulp task.

What this will allow us is to define certain variables that should be applied throughout our app and then reuse them whenever needed.

By doing this we introduce 2 benefits.

  1. We can easily make a change in 1 place that will be applied everywhere that value was used
  2. There is 1 place to check in order to find out what specific values are

The place to define those is f.e. assets/css/helpers/variables.css, so lets create some, that we can use for our grid.

:root {
  /* Container sizes */
  --main-width: 80vw;
  --sidebar-width: 20vw;

  /* Gutter sizes */
  --gutter-horizontal--small: 2vw;
}

Notice that they are wrapped in the :root{} block.

Once this is done the gulp task will automatically make those 'available' in all our CSS files (This is actually done in the build step, but thats semantics I guess).

Lets import them and use them for the grid like this:


@import "./helpers/variables.css";


.grid-container {
  display: grid;
  height: 100%;
  grid-template-columns: var(--sidebar-width) var(--main-width);
  grid-template-rows: 1fr;
  grid-gap: 0px;
  grid-template-areas: "Sidebar Content";
}

.main {
  grid-area: Content;
}

.sidebar {
  grid-area: Sidebar;
}

You can see that the variables are used with var(VARIABLE_NAME). While this might not seem super important or useful right now, be sure that this will save a lot of headaches down the line.

A break in the layout

Ghost theme - Part 2: a Grid

To fix this lets set a max-width on the main container. This does exactly what the name implies, telling it that its maximum width should be of some value.
Which one is the correct value? Given our Layout it should be the --main-width variable. Already comming in handy :).

Lets add it to the .main block

.main {
  grid-area: Content;
  max-width: var(--main-width);
}

Check out the post again. All good?
Nope, looks like the picture is still escaping to the right.

If you inspect the HTML you can find the picture class .kg-image. For this class we will add a rule of max-width: 100%; for now, until we encounter the styling of the pictures again, later on.

Ghost theme - Part 2: a Grid

By the way, you can ignore the purple lines.
These are added by the Firefox developer tools. You can read about these here if you would like to use them too.

A small task for you

Check out the Publishing options article. On this page you should encounter another problem of content escaping.
I will leave this as a small task for you to fix right now. Should you need help or a hint feel free to drop me a short email or contact me on my new twitter.

What next?

The theme already looks quite a bit like the sketch. One thing we need to ensure though, is that there are always only 2 posts next to each other (and maybe alter this idea for mobile devices?).

So the next post will be focussing on those 2 topics including media-queries and flexbox.

Read more
albertomilone@gmail.com

Ubuntu 18.04 marked the transition to a new, more granular, packaging of the NVIDIA drivers, which, unfortunately, combined with a change in logind, and with the previous migration from Lightdm to Gdm3, caused (Intel+NVIDIA) hybrid laptops to stop working the way they used to in Ubuntu 16.xx and older.

The following are the main issues experienced by our users:

  • An increase in power consumption when using the power saving profile (i.e. when the discrete GPU is off).
  • The inability to switch between power profiles on log out (thus requiring a reboot).

We have backported a commit to solve the problem with logind, and I have worked on a few changes in gpu-manager, and in the other key components, to improve the experience when using Gdm3.

NOTE: fixes for Lightdm, and for SDDM still need some work, and will be made available in the next update.

Both issues should be fixed in Ubuntu 18.10, and I have backported my work to Ubuntu 18.04, which is now available for testing.

If you run Ubuntu 18.04, own a hybrid laptop with an Intel and an NVIDIA GPU (supported by the 390 NVIDIA driver),  we would love to get your feedback on the updates in Ubuntu 18.04.

If you are interested, head over to the bug report, follow the instructions at the end of the bug description, and let us know about your experience.

Read more
admin

Hello MAASters!

I’m happy to announce that MAAS 2.5.0 beta 1 has been released. The beta 1 now features

  • Complete proxing of machine communication through the rack controller. This includes DNS, HTTP to metadata server, Proxy with Squid and new in 2.5.0 beta 1, syslog.
  • CentOS 7 & RHEL 7 storage support (Requires a new Curtin version available in PPA).
  • Full networking for KVM pods.
  • ESXi network configuration

For more information, please refer to MAAS Discourse [1].

[1]: https://discourse.maas.io/t/maas-2-5-0-beta-1-released/174

Read more