2021-07-28

Building GitHub Action to publish Hexo post from GitHub Issue

I wanted to write and publish a Hexo post without tedious commands such as git clone, git pull, hexo new, hexo generate, git commit and git push. I saw the feasibility to build an automated publishing system using GitHub Issue and GitHub Actions for this purpose.

Here’s workflow what I thought:

• A user makes an issue, a draft of a post on GitHub Issue
• GitHub Workflow is triggered against the issue
• The workflow converts the issue to a Hexo post

GitHub Issue

I thought that GitHub Issue is a perfect system to draft a post. It has a title, a content and a date/time of update and those information can be a title, a content and a date/time of a post. One thing missing is tags of a post. To achieve this, I got an idea to use labels of an issue as tags of a post.

GitHub Action

I did a research whether there exists GitHub Actions converting an issue to a Hexo post, but I found nothing. So I decided to build a GitHub Action for it.

First of all, it takes two parameters, issue_url and token and extracts endpoint from issue_url:

import * as core from '@actions/core';

const issueUrl = core.getInput('issue_url');
const index = issueUrl.indexOf('/repos');
const endpoint = issueUrl.substring(index);
const token = core.getInput('token');

And then, it initializes Hexo:

import Hexo from 'hexo';

const hexo = new Hexo(process.cwd(), {});
hexo.init().then(() => {
    // Described below
}).catch((reason) => {
    core.setFailed(reason);
});

After Hexo is initialized, it retrieves information of an issue:

import { Octokit } from 'octokit';

// After resolving `hexo.init()`
const gh = new Octokit({ auth: token });

console.log(`Converting issue ${endpoint} to Hexo post...`);
gh.request(`GET ${endpoint}`).then((response) => {
    const { title, updated_at: date, labels, milestone, body: content } = response.data;
    // Described below
}).catch((reason) => {
    core.setFailed(reason);
});

If a draft is set to be published, it derives tags and creates a Hexo post:

const MILESTONE_PUBLISH = 'publish';

if (milestone.title !== MILESTONE_PUBLISH) {
    console.log(`Issue does not have milestone ${MILESTONE_PUBLISH}`);
} else {
    const tags = labels.map((label: any) => label.name);
    hexo.post.create({
        title,
        date,
        tags,
        content,
    } as any);
}

At this point, a markdown file is generated and further actions to be prepared to complete publishing a post. The complete implementation of this action can be found here.

Workflow

Now a complete workflow needs to be setup. The workflow below converts an issue to a post and pushes it to the repository:

name: Issue to Hexo
on:
  issues:
    # Sufficient to trigger this workflow when an issue is milestoned
    types: [ milestoned ]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
        with:
          persist-credentials: 'false'
      - uses: internalstability/[email protected]
        with:
          issue_url: ${{ github.event.issue.url }}
          # Personal access token used to get information of Issue
          token: ${{ secrets.token }}
      # At this point, a markdown file is generated and untracked
      # Take further action, e.g. generate (`hexo generate`), commit and push
      - name: Commit post
        run: |
          git add .
          git config user.name "issue-to-hexo bot"
          git config.user.email "<>"
          git commit -m "Add a post"
      - name: Push
        uses: ad-m/github-push-action@master
        with:
          github_token: ${{ secrets.token }}

I have another workflow which generates (hexo generate) a blog from the pushed code. I made two separate workflows because I both use GitHub Issue to draft a post and manually write and push a markdown draft on my PC. Here’s the workflow:

name: Publish
on:
  push:
    branches: [ master ]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
        with:
          persist-credentials: 'false'
          submodules: 'true'
      - uses: actions/setup-node@v2
        with:
          node-version: '14'
      # This submodule is a directory that contains generated Hexo blog
      - name: Checkout submodule
        run: |
          cd public
          git checkout master
      - name: Build
        run: |
          npm install
          npm run build
      - name: Commit submodule
        run: |
          cd public
          git add .
          git config user.name "internalstability/hexo-src bot"
          git config user.email "<>"
          git commit -m "Publish"
      - name: Push submodule
        uses: ad-m/github-push-action@master
        with:
          github_token: ${{ secrets.token }}
          directory: 'public'
          repository: 'internalstability/internalstability.github.io'
      # These actions commits and pushes the submodule to the main module
      - name: Commit main module
        run: |
          git add .
          git config user.name "internalstability/hexo-src bot"
          git config user.email "<>"
          git commit -m "Publish"
      - name: Push main module
        uses: ad-m/github-push-action@master

GitHub Action, Hexo