Automating the deployment of a cryogen blog to github pages

I like static site generators, clojure and github pages and for those three reasons I happen to like cryogen.

The only "issue" I encountered when I started playing around with cryogen was deployment. I could make a script to push the generated content to kongeor.github.io but that was no fun. This process had to be automated and why not using continuous integration platform like circleci?

Removing the blog-prefix

The first thing to do is to remove the /blog prefix. We want blog content to be in the root. We need to edit the resources/templates/config.edn and remove the :blog-prefix.

Enabling circleci

Circleci is going to deploy our blog to "production".

Create a circle.yml in the root of the project which should looks something like this:

deployment:
  production:
    branch: master
    commands:
      - ./deploy.sh

test:
  override:
    - lein run

We are overriding the default task which is to run tests to compile the blog which will be thrown in resources/public (hacky! I know ...). Then the deploy.sh script is going to run which looks something like this:

git config --global user.email "${GIT_EMAIL}"
git config --global user.name "${GIT_NAME}"

rm -rf build
git clone git@github.com:kongeor/kongeor.github.io.git build
cp -rf resources/public/* build
cd build
git add *
git commit -a -m "build"
git push -u origin master
cd ..

We are configuring git because each build is a fresh new start. GIT_EMAIL and GIT_NAME are pulled from the environmental variables which can be configured in circleci's project settings. Go to dashboard and click the gear near the project.

Then we remove the build directory in case it exist - this is done mostly for convenience for local testing. Then foo.github.io is cloned to build directory. This repo will have only the built static site. The fresh compiled site is copied over it, and with the convenvience of git we add all the files which essentially will have only the diffences, and push the changes.

In order for this thing to work, circleci needs to have permissions to push to that repo.

Setup SSH keys

You need to generate an ssh key. Most probably you already have one, but I don't think that it's a good idea to use that one, because you will need to add your private key to circleci.

Go to project settings under your foo.github.io repo and add your public key.

You need to go once again to project settings in dashboard, find the SSH Permissions settings and add your private SSH key there. You can find more information here.

Test it!

You should be good to test this setup. Create a post, commit and push. Boom! Circleci should fire up the build and when ready it should push the compiled blog to "production".