Publishing your Jekyll blog to AWS S3 and Cloudfront invalidation using Travis CI

Date
Authors
John Nolan

This information is useful once you have signed up to https://travis-ci.org via https://github.com and you have an existing AWS S3 bucket and AWS Cloudfront distribution setup. I will be covering this soon.

At any time you can look at my repo on Github to see how I have set this up.

First create a new directory called script in your root folder and create a file called cibuild. Now past the following details replacing www.nolanscafe.co.uk with your S3 bucket name.

jekyll build
pip install awscli
aws s3 sync --acl public-read --sse --delete _site s3://www.nolanscafe.co.uk
aws configure set preview.cloudfront true
aws cloudfront create-invalidation --distribution-id $CLOUDFRONT_DISTRIBUTION_ID --paths '/*'

This is going to do the following

  • Build our jekyll site
  • Install awscli on the Travis site
  • We then sync our _site directory that has been built by the command jekyll build, deleting all contents on the remote bucket at the same time
  • The line with preview.cloudfront tells the AWS Cli that you want to enable the preview mode of it. This is still in BETA so this allows us access to it.
  • Then finally we invalidate the cache on cloudfront. There are a couple of points on this. First, you are allowed up to 1,000 files to be invalidated per month. After this you are charged. At this point it is around $50 per 1,000. The other is it can take up to 15 minutes for the cache to be invalidated so please be patient.

Now create a .travis.yml file in the root for your directory with the following contents.

language: ruby
dist: trusty
sudo: required
rvm:
- 2.3.3
before_script:
- chmod +x ./script/cibuild
script: "./script/cibuild"
branches:
  only:
  - master

This is our deployment file. This tells Travis what we want to do once it has hold of our files from Github.

  • language: ruby tells it the environment we want to use to run our build (Ruby)
  • dist and sudo tell Travis that we want to run in full trust mode. This is required for using the awscli library
  • script tells Travis to use our file we created previously to be run
  • branches tells Travis to... only build our master branch

Now, before we commit and push to Github we need to setup credentials for awscli, to allow it to connect to our account.

Log into https://travis-ci.org and find your repo. In the More options drop down select Settings. Here you will find an area called Environment Variables.

Here add your AWS Access Key, AWS Secret Key, S3 Bucket Region and your AWS Cloudfront Distribution Id for Cloudfront. This can be found in the General tab in your AWS Cloudfront distribution dashboard.

It is important to name these exactly like so

  • AWS_ACCESS_KEY_ID
  • AWS_DEFAULT_REGION
  • AWS_SECRET_ACCESS_KEY
  • CLOUDFRONT_DISTRIBUTION_ID

These keys are stored as Environmental Variables that can be accessed in your Travis build script and are all encrypted.

Never put sensitive information in your Github Repo

You should now be all setup ready for continuous integration. Commit and Push these changes to Github and now Travis should receive the trigger and use the .travis.yml file and cibuild to execute your Jekyll and AWS S3 and Cloudfront deployment.