Build Hexo site with Azure Pipelines

Azure Pipelines has the very good integration with GitHub. It provides 10 free parallel jobs and unlimited minutes for open source projects. It is a very good choice for open source projects to have the CI/CD capability.

As I have configured the site to use hexo’s git deployment, an Azure build pipeline is enough to carry out the deployment. And in the build pipeline, I need the following three tasks.

• Install hexo-cli.
• Install all npm packages used by the site with npm install.
• Configure git credential and run hexo deploy.

The first 2 steps are quite straight forward. The tricky part is how to use script to configure git credentials. git credential store only accept inputs from stdin. I did some search and tests, and ended up with a bash pipe to feed in the credentials. The following is a sample for credential store.

git config --global user.email "<git email address>"
git config --global user.name "<git user name>"   
git config --global credential.helper 'store --file ~/.my-credentials'
printf "protocol=https\nhost=github.com\nusername=<username>\npassword=%s\n\n" "$GHP" | git credential-store --file ~/.my-credentials store
./node_modules/.bin/hexo clean && ./node_modules/.bin/hexo deploy

As credential store will save the credential to a file on disk, it is not a good practice for a shared build agent. I ended up to replace the credential store with credential cache, and exit the cache when deployment is done.

The following is the yaml file of the build definition. $GHP is an environment variable storing the personal token of GitHub. The actual value is saved in Azure DevOps encrypted.

resources:
- repo: self
queue:
  name: Hosted Ubuntu 1604
  demands: npm

steps:
- script: |
   echo "install hexo-cli"   
   npm install hexo-cli

  displayName: 'Install hexo-cli'

- task: Npm@1
  displayName: 'npm install'
  inputs:
    workingDir: /

    verbose: false

- script: |
   git config --global user.email "<git email address>"   
   git config --global user.name "<git user name>"   
   git config --global credential.helper cache   
   printf "protocol=https\nhost=github.com\nusername=<username>\npassword=%s\n\n" "$GHP" | git credential-cache store   
   ./node_modules/.bin/hexo clean && ./node_modules/.bin/hexo deploy   
   git credential-cache exit
  displayName: 'hexo deploy'
  env:
    GHP: $(password)

Now when I update the site, I just need to commit the changes and push it to GitHub. Azure Pipeline will take care of the build and deployment automatically.