Auto-deploying to my Octopress blog with Travis-CI

A couple weeks earlier, Sergey Klimov (who is @darvin at GitHub) opened the issue #940 at imathis/octopress, which is more a feature suggestion than an issue.

Within that, he has linked to his detailed blog post suggesting how the awesome Travis-CI could be configured to do the rake generate and rake deploy for you, when you add/update new posts to an octopress blog, even from browser-based editors like either the built-in GitHub editor, or a third-party tool like the prose.io editor (which is really awesome too, BTW).

For the uninitiated, Travis-CI is a really nice, open source, free and hosted continuous integration service that could build and run the unit tests for you, on every commit to a GitHub repository. It supports projects in a multitude of languages, as seen here. The service allows you to configure steps that would be run before, after and during the build and test process, with just one YAML file (named .travis.yml) in the root of your repo. Apart from running the many unit tests in the project and letting you know how your latest check-in affected the health of the project, the Travis-CI service could also do custom build tasks like a post-build deployment. And this is what Sergey has tappped into, for use with the deployment of an Octopress blog.

His blog post really has everything that one would need to set-up Travis-CI for automating the deployment of their blog. This post here is trying to add a couple of tweaks that were done, when I successfuly enabled auto-deploy for this blog of mine, the source of which can be seen at floydpink/harimenon.com. (Also, this very post, is in-fact composed on a browser, thanks to prose.io service).

1. Revert _config.yml

As the before_script is using rake setup_github_pages task every time on Travis to setup the _deploy git correctly, it was overwriting the _config.yml url value to the github url, which would be a problem, if like me, you are deploying this to a custom domain.

 #      Main Configs       #
 # ----------------------- #

-url: https://harimenon.com
+url: http://floydpink.github.com/harimenon
 title: Hari Menon
 subtitle: Namaste. Welcome to my personal space on the world wide web!
 author: Hari Menon

This subtle little thing was manifest only in the tweet button behavior (which fortunately, I noticed when I was trying to tweet this very post) as seen in this screenshot:

Instead of the correct URL - https://harimenon.com/blog/2012/12/16/aop-for-logging-in-net/, the tweet was showing - http://floydpink.github.com/harimenon/blog/2012/12/16/aop-for-logging-in-net/.

To fix this, we should add an additional line to revert the _config.yml (especially for the blogs that are hosted with cutom URLs).

   - echo -e "Host github.com\n\tStrictHostKeyChecking no\n" >> ~/.ssh/config
   # Set deployment target to github pages
   - rake setup_github_pages[$REPO]
+  # To reset the 'url' to the custom domain in '_config.yml'
+  - git checkout -- _config.yml
 script:
   # Generate site
   - rake generate

2. Add [ci skip] to the commit message

As a P.S. to his blog post, Sergey talks about how Travis builds the project twice once for the original commit (with the intended changes to the blog) and second because of the commit from the rake deploy applied by this first Travis build (all of this is because, it seems the branches setting in the .travis.yml that limits it to the source branch only does not seem to work). And he has a clever workaround in the after_script to stop this at the second build itself rather than going into an infinite loop - 'echo ''script: "ls *.html"'' > public/.travis.yml'. I tweaked this a little bit as below:

From one of the earlier encounters, I remembered that the Travis-CI documentation does detail how a specific commit could be made to skip the ci build. Just by including [ci skip] (including the brackets) somewhere in the commit message. So the first tweak I did is this in the Rakefile:

     system "git add ."
     system "git add -u"
     puts "\n## Commiting: Site updated at #{Time.now.utc}"
-    message = "Site updated at #{Time.now.utc}"
+    message = "Site updated at #{Time.now.utc} [ci skip]"
     system "git commit -m \"#{message}\""
     puts "\n## Pushing generated #{deploy_dir} website"
     system "git push origin #{deploy_branch} --force"

3. Syntax changes in using the travis command line tool to encrypt deploy key

Also, because I had to upgrade to the latest version of the Travis, which has slightly different command-line syntaxes now, I had to tweak the script he has referred to, to generate the secure argument for the deploy key. My version is as below:

The difference essentially is only in the ENCRYPTION_FILTER environment variable, that holds the way the travis command line client would be used to generate the encrypted deploy key.

One more occasion, where I feel like I have done something a la a dwarf standing on the shoulders of giants.