How can we use environment variables in a Jekyll config file? - ruby

Question

Is there a way I can use one my bash environment variable (say $FOO) in my Jekyll's _config.yml file?
I've tried using:
foo = <%= ENV['FOO'] %>
But it didn't work as the Ruby code wasn't interpreted.
Versions used:
Ruby: 2.1.2
Jekyll: 2.5.3

Answer 1

If your goal is to use environment variables as liquid items {{ site.something }}, you might be able to get this thing in your Gemfile a go:
gem 'jekyll-environment-variables', group: :jekyll_plugins
And then you'll be able to use {{ site.env.HOME }} and expect it be converted to something like /home/ubuntu in the output HTML.
Disclosure: I am the owner of the gem and I've been using it personally since long ago.

Answer 2

The answer by #elryco is close but not quite right, at least for my setup. It took some trial and error, but this finally worked. Note this only works for certain env vars supported by the contentful plugin.
Note that you need the gem jekyll-contentful-data-import (v1.7.0 or up) for this solution to actually work.
Bash environment (e.g., ~/.bash_profile):
export CONTENTFUL_ACCESS_TOKEN=foo
export CONTENTFUL_SPACE_ID=bar
In _config.yml, reference them as:
contentful:
spaces:
- example:
space: ENV_CONTENTFUL_SPACE_ID
access_token: ENV_CONTENTFUL_ACCESS_TOKEN
This is the same as what's written in the Github documentation.

Answer 3

I recently had to try and do this myself. It turns out you can't put environment variables directly into a Jekyll config file, but you can write a rake task that will take environment variables and apply them to your config.
Here's an example:
# Rakefile
require 'jekyll'
task default: %w[build]
desc "Build the site"
task :build do
config = Jekyll.configuration({
url: ENV["SITE_URL"],
})
site = Jekyll::Site.new(config)
Jekyll::Commands::Build.build(site, config)
end

Answer 4

Unfortunately there is no direct way of accessing it in liquid tags, At Least not officially.
But I wrote a wrapper script which reads environment variables before jekyll starts and appends it to _config.yml file and deletes the variable post build.
echo "secret-variable: $PASSWORD" >> _config.yml
bundle exec jekyll build -d target
sed '$d' _config.yml //this is to delete the last line
Now I'm free to use site.secret-variable anywhere in the liquid tags.
I know that this not the right way of doing it, But so is writing a custom ruby script.

Answer 5

I personally find the use of a ruby Jekyll plugin more appropriate and portable. There's a very simple yet effective solution available here.
The main idea is ruby will have access to the ENV variables so you can use a small ruby plugin to load into your site.config liquid array all the information you want from the environment. And you can define default values as well.
Please note that the example given in the link isn't the most relevant since the prod/staging environment is already offered by Jekyll natively with the build command options.

Answer 6

It is now possible to use bash environment variable (say $FOO) in Jekyll's _config.yml file with GitHub Actions:
# _config.yml
title: FOO
Create a bash script say sample.sh to replace for a given input string FOO and replace with another string
# github/workflows/sample.sh
export FOO=XYZ
while IFS='' read -r a; do
echo "${a//FOO/$FOO}"
done < /_config.yml > /_config.yml.t
mv /_config.yml{.t,}
Create a workflow file, say github-pages.yml, put the script before Build with Jekyll:
# Sample workflow for building and deploying a Jekyll site to GitHub Pages
name: Deploy Jekyll with GitHub Pages dependencies preinstalled
on:
# Runs on pushes targeting the default branch
push:
branches:
- 'master'
- 'mybranch'
# Allows you to run this workflow manually from the Actions tab
workflow_dispatch:
# Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
permissions:
contents: read
pages: write
id-token: write
# Allow one concurrent deployment
concurrency:
group: "pages"
cancel-in-progress: true
jobs:
# Build job
build:
runs-on: ubuntu-latest
steps:
- name: Checkout
uses: actions/checkout#v3
- name: Setup Pages
uses: actions/configure-pages#v2
- name: Utilize FOO
run: |
bash .github/workflows/sample.sh
- name: Build with Jekyll
uses: actions/jekyll-build-pages#v1
with:
source: ./
destination: ./_site
- name: Upload artifact
uses: actions/upload-pages-artifact#v1
# Deployment job
deploy:
environment:
name: github-pages
url: ${{ steps.deployment.outputs.page_url }}
runs-on: ubuntu-latest
needs: build
steps:
- name: Deploy to GitHub Pages
id: deployment
uses: actions/deploy-pages#v1

Answer 7

If your bash environment variables are declared like this
export ENV_ACCESS_TOKEN=xxxxx
export ENV_SPACE_ID=yyyyyy
You can get it like this in your config.yml
space: ENV_SPACE_ID # Required
access_token: ENV_ACCESS_TOKEN # Required