Removes old docker tags, while keeping the last imagesToKeep number.

remove-old-images.js

const http = require('https')
const url = require('url')
const repo = process.argv[2]
const imagesToKeep = 5
const baseUrl = `https://USERNAME:PASSWORD@reg.your.com/v2/${repo}/`
console.info('removing old images for repo: ', repo)

http.get(`${baseUrl}tags/list`, res => {
  let body = ''
  res.on('data', (d) => {
    body += d
  })
  res.on('end', () => {
    const tags = JSON.parse(body).tags
    const promises = []
    //console.log(`tags: %j`, tags)
    tags.forEach(tag => {
      promises.push(new Promise((resolve, reject) => {
        const options = url.parse(`${baseUrl}manifests/${tag}`)
        //console.log('asking tag with options: ', options)
        Promise.all([
          new Promise((resolve, reject) => {
            // get the correct digest via v2
            // @see: https://github.com/docker/distribution/blob/master/docs/spec/api.md#deleting-an-image
            http.get(Object.assign({Accept: 'application/vnd.docker.distribution.manifest.v2+json'}, options), res => {
              const digest = res.headers['docker-content-digest']
              resolve(digest)
            }).on('error', (e) => {
              console.error(`error: ${e.message}`)
              reject(e)
            })
          }),
          new Promise((resolve, reject) => {
            // get the image created timestamp via v1
            http.get(options, res => {
              let body = ''
              res.on('data', (d) => {
                body += d
              })
              res.on('end', () => {
                const json = JSON.parse(body)
                console.log(`json for tag ${tag}: `, json)
                lastOp = JSON.parse(json.history.shift().v1Compatibility).created
                console.log(`lastOp for tag ${tag}: `, lastOp)
                resolve(lastOp)
              })
            }).on('error', (e) => {
              console.error(`error: ${e.message}`)
              reject(e)
            })
          })
        ]).then(([digest, lastOp]) => {
          resolve({tag, digest, lastOp})
        }).catch(reject)
      }))
    })
    Promise.all(promises).then(tagList => {
      // sort tagList by date, newest first, and select all but latest 5, including 'latest'
      const deleteTagList = tagList.sort((a, b) => {
        return new Date(b.lastOp).getTime() - new Date(a.lastOp).getTime()
      }).slice(imagesToKeep + 1)
      //console.log(`deleteTagList: `, deleteTagList)
      deleteTagList.forEach(item => {
        console.log('deleting tag: ', item.tag)
        const options = url.parse(`${baseUrl}manifests/${item.digest}`)
        options.method = 'DELETE'
        //console.log('deleting with options: ', options)
        //http.request(options, res => {
        //  console.log(`status code for deletion of tag ${item.tag}: `, res.statusCode)
        //}).on('error', (e) => {
        //  console.error(`error: ${e.message}`)
        //}).end()
      })
    })
  })
}).on('error', (e) => {
  console.error(`error: ${e.message}`)
})