How This Static Blog Uses Travis-CI

Update: I’ve switched to Hakyll, but the instructions below should continue to work.

When I started this blog, I was reluctant to put a continuous integration system like Travis-CI in charge of deployment because it seemed like a frivolous use of resources and so I settled for the approach outlined here which worked reasonably well. As my understanding of continuous integration and the possibilities of Travis improved, I changed my mind and decided it would be a good idea to automate this process. I also realised that automating my deployment would allow me to theoretically create or update a post using the GitHub web interface which would automatically get turned into a new post on my blog. This would allow me to use this blog from any web browser! In other words, I wanted a convoluted reimplementation of half of a CMS’s functionality.

I found a very helpful blog post that covered most of the details I needed. Let me go through the changes I made.

First off, I use Python 3 wherever possible so I simplified my requirements.txt:

pelican
Markdown

My .travis.yml is different too (I removed unnecessary nesting to make it shorter):

branches:
  only: master
language: python
python: 3.6
cache: pip
script: make html
notifications:
  email:
    on_success: always
    on_failure: always
before_install: git submodule update --init --recursive
after_success: bash deploy.sh
env:
  global:
secure: Ew3edSrbYr/rofui49TpBTbmHivreifr0FLjqP+1CBPXERKEsCjs9thWBnjKIZYirfetMb5ShF9EZ1g8D459BS7Sn+ziXUP4X3I4jvdx1Yj55o2CuWOD6Gx6ShPkWEhZRZhFFIKpGfLO4XAKP3suSPJvB1Lp67GC0BFyPucSSU8=

I installed the travis gem, got a GitHub token, and tried to set the token with

travis encrypt GH_TOKEN=LONGTOKENFROMGITHUB --add env.global

but it didn’t recognise my repository until I went to my Travis-CI profile, enabled GitHub access, and enabled it to check my repository.

The deploy.sh script was almost the same (change your username):

#!/usr/bin/env bash
BRANCH=master
TARGET_REPO=vaibhavsagar/vaibhavsagar.github.io.git
PELICAN_OUTPUT_FOLDER=output

if [ "$TRAVIS_PULL_REQUEST" == "false" ]; then
    echo -e "Starting to deploy to Github Pages\n"
    if [ "$TRAVIS" == "true" ]; then
        git config --global user.email "travis@travis-ci.org"
        git config --global user.name "Travis"
    fi
    # using token, clone gh-pages branch
    git clone --depth 1 --quiet --branch=$BRANCH https://${GH_TOKEN}@github.com/$TARGET_REPO built_website > /dev/null
    # go into directory and copy data we're interested in to that directory
    cd built_website
    rsync -av --delete --exclude=.git  ../$PELICAN_OUTPUT_FOLDER/ ./
    # add, commit and push files
    git add -A
    git commit -m "Travis build $TRAVIS_BUILD_NUMBER pushed to Github Pages"
    git push -fq origin $BRANCH > /dev/null
    echo -e "Deploy completed\n"
fi

and that was all the setup I had to do. I then pushed a commit and watched as Pelican and its dependencies were downloaded, my blog posts were regenerated, and my GitHub Pages repo was updated. Seems a bit wasteful, but it was surprisingly easy to get working and it performs admirably.