Hello everyone! I’m starting my new blog site. This blog site is hosted by Github pages and use Jekyll as blog engine. For this first blog post, let’s see how to create such a blog post: I’m going to detail all the steps to create a blog site with Jekyll, Github Pages, Docker, Eclipse Che cloud IDE and Codenvy.

You can right away help me in improving this blog site by clicking on this link open in IDE. If this is the first time, pay attention to the blocked popup: please authorize popup dialog boxes from codenvy.com, go back the this blog post and click again on this link. The link will open the blog site project in a temporary workspace at Codenvy. You will then be able to submit your changes as Github pull requests. Thanks in advance for your contribution!

For the next blog post, I will explain how to create this kind of link for your Github project.

1. Tools in action: Jekyll, Github Pages, Che, Codenvy, Docker

Websites hosted by Github: Github Pages

Github offers free website hosting. This is called Github Pages. Hosting website with Github Pages has some advantages:

  • It’s free.
  • It’s maintained by Github. We won’t need to deal with upgrades of your server, down times, etc.
  • It’s versioned with Git. Track all your changes.
  • We don’t depend on Github. If Github stop Pages service, it won’t be a problem to host the site elsewhere.

With Github Pages, each site is actually a Github project. You can use it for your full static website or use the available Jekyll blog site generator.

What is Jekyll?

Github Pages comes with Jekyll. Jekyll is “a simple, blog aware, static site generator”. It takes markdown files and template files as input and merges them to generate a static site. Thus, there is no database to deal with, no security issue, no performance issue. For our blog site, we are going to create our site on a new Github project. A Jekyll project is composed of several folders prefixed by _:

  • _includes contains headers, footers, menus, sidebars to be included in your pages
  • _layouts contains the template files
  • _posts contains your blog posts files
  • _sass contains scripted CSS using Sass

All theses folders are templates or sass css that will be use to generate the static site. If you have any folders not starting with _, these ones won’t change and stay statics.

For Github Pages sites, Github will regenerate the site with Jekyll each time a modification is done in your Github git project.


Docker is a container technology. As opposed to virtualisation (Virtual box or VMWare), containers are lightweight: containers use isolated and native host processes. When a Docker image is running, all the processes are actually running on the host machine. Thus, Docker can run only machines based on the operating system kernel. For instance, you can run any linux distribution on a Docker hosted by linux. Docker offers a way to write and build images based on recipes with inheritance capabilities. You write how to build an image providing linux command to run. Typically, we will run commands using apt-get install or wget http://archive.zip && unzip archive.zip to build our images. Docker is a nice tool for developers as it describes a reproducible way to build an image. You can share the recipe of your Docker image and use Git to keep all the change history of this file. Anyone can then rebuild your image. It’s like you have the source code of your virtual machine.

Eclipse Che hosted by Codenvy

When writing our blog post, we may not want to publish the site to ‘production’ each time you make a change just to see how it looks like. To test the site before publishing it, we could install Jekyll locally on our computer and run the site generation locally for testing. However, installing Jekyll is not that easy. Ruby, NodeJS and gem are required and the installation steps may differ from one system to another. Plus, we want to have our editing environment available from anywhere. We are going to use an Eclipse Che hosted by Codenvy. Eclipse Che is a Cloud IDE and we will use it to edit our blog site, test it and push the changes to Github. Codenvy provides a Docker infrastructure on the cloud to run your applications. You don’t have to install anything: everything will be available from a browser. We will be able to create our Docker recipe, generate and run our Jekyll site … from anywhere, with any device.

2. Choose a theme

Let’s start creating our blog site. First of all, we won’t start from scratch but reuse an existing Jekyll theme to bootstrap our site. In the site http://jekyllthemes.org/, we can find a lot of theme for Jekyll. The site samples are complete and ready to use. As far as I’m concerned, I’ve chosen this one: Freshman21.

3. Fork Jekyll theme in your Github

Once logged in Github.com, we will fork the Freshman21 project. You can fork it from https://github.com/yulijia/freshman21.


fork choose


You can try the result of the forked theme right away http://yourgithubname.github.io/freshman21.

Main website

With Github Pages, a site can be served directly from http://yourgithubname.github.io or http://yourgithubname.github.io/asitename If this is going to be your main site, rename it yourgithubname.github.com. The site will be available in http://yourgithubname.github.io/. If not, Github will use the branch gh-pages that will be used by Github Pages. The site will be available at http://yourgithubname.github.io/githubProjectName/.

Freshman21 themes already include both branches. In this project, they represent 2 differents versions of the site (with and without javascript).

In our case, we are going to start from the gh-pages branch version.

4. Import in Codenvy Eclipse Che

In Codenvy website, log in with your Github account and import the forked project.


import from github

dashboard project

Open (double click) the project.

Normally Eclipse Che should ask to configure your project. Configure the project by choosing blank as project type.



At that point, we should have the IDE opened with the freshman21 project.

gh-pages branch

if the site is going to be your main Github Pages site, you can skip this part. Otherwise, from the Git > Branches ... menu action, checkout the branch gh-pages.

che branches

che create and checkout

5. Test in Codenvy

To test the site before pushing it, we can run the jekyll generator with a custom Docker runner.

Create a new Custom Runner in Runners - Configs tab, create a new configuration.

che runner create

Rename it Jekyll.

che runner jekyll

Paste this content:

FROM sunix/jekyll4che

VOLUME ["/home/user/app"]

USER root
WORKDIR /home/user/app

CMD echo 'url: "http://'$CODENVY_HOSTNAME':'$CODENVY_PORT_4000'"' >> _config.yml && \
    echo 'baseurl: ""' >> _config.yml && \
    jekyll serve

Save and start the runner. Once started, the running site link should be available. che runner run

che runner link

che runner app

Use Dockerhub prebuilt images to speed up

We use sunix/jekyll4che image that’s been built by Dockerhub. If not cached, instead of executing all the steps to install the application, it will download a prebuilt image and speed up the startup of our application.

sunix/jekyll4che looks like:

FROM codenvy/shellinabox
RUN sudo apt-get update && \
    sudo apt-get upgrade -y && \
    sudo apt-get install -y ruby ruby-dev patch nodejs python locales && \
    sudo gem install github-pages
RUN sudo dpkg-reconfigure locales && \
  sudo locale-gen C.UTF-8 && \
  sudo /usr/sbin/update-locale LANG=C.UTF-8

Mounting volume instead of copying sources

Right away, you can try the generated site by clicking on the link just below the runner panel. We didn’t use the ADD comment

ADD $app_src$ /home/user/app/

But the VOLUME Docker command to mount sources. This way, modifications are live updated on runners. FYI, changes done on _config.yml won’t get reloaded. You will need to restart the Docker runner.

Overriding url configuration at runtime

The last lines of the Dockerfile override the base url and the url so that the site works well when running on Eclipse Che Docker AND on Github Pages.

6. Customisation

Create a new blog post

First, remove all the blog posts files that are coming with the theme in _posts folder.

To create a new blog post, create a new .md file in the _posts folder. The file should start with headers:

layout: post
title: A blog site with Jekyll, Github pages Eclipse Che and Codenvy
modified: 2015-01-11
categories: [articles, Howto]
  - blog
  - jekyll
  - codenvy
  - eclipse che
  - github pages
comments: true
## Your first blog post !
hello world

Then you can write traditional text using the markdown syntax. You have written your first blog post!

I really recommand you to read this Jekyll documentation for your first blog post.

Site configuration

_config.yml contains all the site configuration that you may want to customize. Here are the ones I have changed:

  • title: The title (html) of the site. The title is also displayed on top of each page.
  • tagline: A description of the site, will be display in h3 between the title and the menu
  • author: Your name. Will be displayed in the ‘about me’ page
  • email: Your email.
  • description: It will appear in your document head meta and in your feed.xml site
  • keywords: the keywords
  • baseurl: the subpath of your site, e.g. /blog/. if this is not your main page, it should be the name of your Github project.
  • url: should be http://yourusername.github.io
  • twitter_username
  • github_username
  • disqus_shortname: subscribe to disqus, register your website and get comments on your site
  • aboutme: about you
  • aboutme_photo: url to your photo
  • google_analytics_key: put YOUR key here to enable tracking! (blank to disable)

7. Push to Github

Once we are happy, with our site, we would like to push our changes to Github. First commit your changes:

  • select the new and modified files and select the menu action: Git > Add to index...
  • commit your changes Git > Commit...

Push your changes to Github Git > Remotes... > Push...

You should normally have your changes pushed on your project and your website updated.

8. DNS Github Pages setup

If you have your own DNS, create a new CNAME file and add your DNS name on it. As far as I’m concerned, I have a CNAME file with:


And I have added a new CNAME entry in my DNS configure at Gandi:

TTL: 3 hours
Name: blog
Value: sunix.github.io.

Also I’ve updated _config.yml url and base url:

baseurl: ""
url: "http://blog.sunix.org"

9. Comments with disqus

By default, the Jekyll theme comes with an integration to disqus. You can create an account on disqus and update the _config.yml accordingly.

Once logged on disqus, you can add disqus to your site from the menu action Add Disqus To Site. disqus add to site

Fill your site name and the short name (will be used for the unique disqus URL). disqus config

Finally update your _config.yml file with your disqus shortname

disqus_shortname: sunix

From now, people will be able to add comments on your blog posts.

Done !

That’s all, don’t hesitate to make any comments and improve this blog post and open in IDE :) thank YOU for reading.