GitHub Artifact Fetcher

Dockerfile

# Example build and run:
# 	docker build -t github_artifact_fetcher .
# 	docker run -e "GITHUB_TOKEN=$(gh auth token)" -v /var/www/artifacts:/artifacts -p 3000:3000 --name github_artifact_fetcher github_artifact_fetcher
FROM node:alpine
RUN apk add --no-cache curl jq
ENV PORT=3000 DEST_DIR=/artifacts
WORKDIR /app
ADD server.mjs .
CMD ["node", "./server.mjs"]
EXPOSE $PORT

server.mjs

import { createServer } from 'node:http'
import { exec } from 'node:child_process'
import { readdirSync } from 'node:fs'

// GitHub Artifact Fetcher -
// Downloads a GitHub artifact from a repository and saves it to a local directory.
//
// Example requests:
//  curl -X POST -d '{"repo":"owner/repo","artifactId":1234}' http://localhost:3000/
//  curl -X POST -d '{"repo":"owner/repo","artifactId":1234,"destName":"docs"}' http://localhost:3000/
//
// Note: "owner/repo" must be existing directories in `DEST_DIR`.

const TOKEN = process.env.GITHUB_TOKEN
const PORT = process.env.PORT
const DEST_DIR = process.env.DEST_DIR?.replace(/\/$/, '')

if (!TOKEN || !PORT || !DEST_DIR) {
  console.error('Missing required environment variables')
  process.exit(1)
}

const headers = `-H "Accept: application/vnd.github+json" -H "Authorization: Bearer ${TOKEN}" -H "X-GitHub-Api-Version: 2022-11-28"`
const allowedRepos = getDirnames(DEST_DIR).flatMap(owner =>
  getDirnames(`${DEST_DIR}/${owner}`).map(repo => `${owner}/${repo}`)
)
console.log(`Starting GitHub Artifact Fetcher server for repositories:\n ${allowedRepos.join('\n ')}\n`)

const server = createServer((req, res) => {
  let params = []
  req
    .on('data', chunk => {
      params.push(chunk)
    })
    .on('end', () => {
      try {
        params = JSON.parse(Buffer.concat(params).toString())
      } catch (e) {
        params = {}
      }

      const isValidRequest = (
        req.method === 'POST' && req.url === '/' &&
        (typeof params.repo === 'string' ? allowedRepos.includes(params.repo) : false) &&
        Number.isInteger(params.artifactId) &&
        (params.destName ? /^[a-zA-Z0-9-_.]+$/.test(params.destName) : true)
      )

      if (!isValidRequest) {
        console.error('Invalid request', { url: req.url, method: req.method, params })
        return
      }

      const apiUrl = `https://api.github.com/repos/${params.repo}/actions/artifacts/${params.artifactId}`

      console.log(`Getting artifact ${params.artifactId} from ${params.repo}`)
      exec(`curl -L ${headers} ${apiUrl} | jq -r .archive_download_url`, (err, stdout) => {
        if (err) {
          console.error(err)
          return
        }

        const downloadUrl = stdout.trim()
        if (downloadUrl === 'null') {
          console.error(`Artifact ${params.artifactId} for ${params.repo} not found`)
          return
        }

        console.log(`Downloading artifact from ${downloadUrl}`)
        const destPath = `${DEST_DIR}/${params.repo}/${params.destName || params.artifactId}`
        exec(`curl -L ${headers} -o ${destPath}.zip ${downloadUrl}`, (err) => {
          if (err) {
            console.error(err)
            return
          }

          exec(`unzip -o ${destPath}.zip -d ${destPath}`, (err) => {
            if (err) {
              console.error(err)
              return
            }
            console.log(`Artifact ${params.artifactId} saved to ${destPath}`)
          })
        })
      })
    })

  res.writeHead(200, { 'Content-Type': 'text/plain' })
  res.end()
})

server.listen(PORT, '0.0.0.0', () => {
  console.log(`Listening on 0.0.0.0:${PORT}/`)
})

function getDirnames(path) {
  return readdirSync(path, { withFileTypes: true })
    .filter(dirent => dirent.isDirectory())
    .map(dirent => dirent.name)
}