feat(plugin): add basic support for github actions

There have been several requests to gain access or over ride the build
id of the image so that the caller can control that and reference it
later in a build process. Initial attempts to expose this information
from the nextRelease property. Unfortunately, this object seems to be
sandboxed, and additional information is not carried to other plugins.
As an alternative, this adds basic support for github actions be setting
output and environment variable that include the build id and image sha
where possible

fixes: #49

README.md

@@ -277,6 +277,34 @@ the default docker image tags for the 1.0.0 release would be `1.0.0`, `1-latest`
 the docker tags for version `1.2.3` will be `1.2.3`, `1.2-latest`, `1-latest` and `latest`
 the docker tags for version `2.3.4-beta.6` will be `2.3.4-beta.6`, `2.3-beta`, `2-beta` and `beta`
 
+## GitHub Actions
+
+The plugin has some basic support for github actions by exposing several outputs and environment variables
+during the publish stage
+
+> [!WARNING]
+>
+> When using buildx image shas are different per platform, and as such using the shas directly
+> is not supported and may result in unexpected results.
+
+### Outputs
+
+| name                     | description                                                                        | example                                                            |
+|--------------------------|------------------------------------------------------------------------------------|--------------------------------------------------------------------|
+| `docker_image`           | The full name of the docker image including the registry, sans any tag information | quay.io/codedependant/my-image                                     |
+| `docker_image_build_id`  | The unique build id used to initial build the image during a release               |                                                                    |
+| `docker_image_sha_short` | A shorted version of the image sha value suitable for referencing the image        | `b94d27b9934d3e0`                                                  |
+| `docker_image_sha_long`  | The full sha256 value that points the image that was build during a release        | `b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9` |
+
+### Environment Variables
+
+| name                                      | description                                                                        | example                                                            |
+|-------------------------------------------|------------------------------------------------------------------------------------|--------------------------------------------------------------------|
+| `SEMANTIC_RELEASE_DOCKER_IMAGE`           | The full name of the docker image including the registry, sans any tag information | quay.io/codedependant/my-image                                     |
+| `SEMANTIC_RELEASE_DOCKER_IMAGE_BUILD_ID`  | The unique build id used to initial build the image during a release               |                                                                    |
+| `SEMANTIC_RELEASE_DOCKER_IMAGE_SHA_SHORT` | A shorted version of the image sha value suitable for referencing the image        | `b94d27b9934d3e0`                                                  |
+| `SEMANTIC_RELEASE_DOCKER_IMAGE_SHA_LONG`  | The full sha256 value that points the image that was build during a release        | `b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9` |
+
 ## Development
 
 ### Docker Registry

index.js

@@ -1,6 +1,7 @@
 'use strict'
 
 const crypto = require('crypto')
+const docker = require('./lib/docker/index.js')
 const dockerPrepare = require('./lib/prepare.js')
 const dockerVerify = require('./lib/verify.js')
 const dockerPublish = require('./lib/publish.js')
@@ -9,6 +10,7 @@ const dockerSuccess = require('./lib/success.js')
 const dockerFail = require('./lib/fail.js')
 const build_id = crypto.randomBytes(10).toString('hex')
 
+let image
 module.exports = {
   buildConfig
 , fail
@@ -18,22 +20,33 @@ module.exports = {
 , verifyConditions
 }
 
+/* istanbul ignore next */
 async function fail(config, context) {
-  return dockerFail(await buildConfig(build_id, config, context), context)
+  const opts = await buildConfig(build_id, config, context)
+  context.image = image || docker.Image.from(opts, context)
+  return dockerFail(opts, context)
 }
 
 async function prepare(config, context) {
-  return dockerPrepare(await buildConfig(build_id, config, context), context)
+  const opts = await buildConfig(build_id, config, context)
+  image = await dockerPrepare(opts, context)
+  return image
 }
 
 async function publish(config, context) {
-  return dockerPublish(await buildConfig(build_id, config, context), context)
+  const opts = await buildConfig(build_id, config, context)
+  context.image = image || docker.Image.from(opts, context)
+  return dockerPublish(opts, context)
 }
 
 async function success(config, context) {
-  return dockerSuccess(await buildConfig(build_id, config, context), context)
+  const opts = await buildConfig(build_id, config, context)
+  context.image = image || docker.Image.from(opts, context)
+  return dockerSuccess(opts, context)
 }
 
 async function verifyConditions(config, context) {
-  return dockerVerify(await buildConfig(build_id, config, context), context)
+  const opts = await buildConfig(build_id, config, context)
+  context.image = image || docker.Image.from(opts, context)
+  return dockerVerify(opts, context)
 }

lib/docker/image.js

@@ -7,7 +7,7 @@ const execa = require('execa')
 const buildTemplateVars = require('../build-template-vars.js')
 const array = require('../lang/array/index.js')
 const string = require('../lang/string/index.js')
-const SHA_REGEX = /(?:writing image\s)?[^@](?:sha\d{3}):(?<sha>\w+)/i
+const SHA_REGEX = /(?:writing image\s)?[^@]?(?:sha\d{3}):(?<sha>\w+)/i
 
 function render(item, vars) {
   if (Array.isArray(item)) {
@@ -43,6 +43,7 @@ class Image {
     }
 
     this.sha = sha
+    this.sha256 = null
     this.opts = {
       build_id: build_id
     , args: new Map()
@@ -62,7 +63,6 @@ class Image {
 
     if (quiet) this.flag('quiet', null)
 
-
     for (const tag of this.tags) {
       this.flag('tag', tag)
     }
@@ -273,11 +273,12 @@ class Image {
       const line = lines[x]
       const match = SHA_REGEX.exec(line)
       if (match) {
-        this.sha = match.groups.sha.substring(0, 12)
+        this.sha256 = match.groups.sha
+        this.sha = this.sha256.substring(0, 12)
         return this.sha
       }
     }
-    this.sha = this.build_id
+    this.sha = this.opts.build_id
     return this.sha
   }
 

lib/prepare.js

@@ -5,10 +5,9 @@ const docker = require('./docker/index.js')
 module.exports = dockerPrepare
 
 async function dockerPrepare(opts, context) {
-  const image = docker.Image.from(opts, context)
+  const {image = docker.Image.from(opts, context)} = context
   context.logger.info('building image', image.name)
   context.logger.info('build command: docker %s', image.build_cmd.join(' '))
-
   await image.build()
   return image
 }

lib/publish.js

@@ -1,10 +1,24 @@
 'use strict'
 
+const actions = require('@actions/core')
 const docker = require('./docker/index.js')
 
 module.exports = publish
 
 async function publish(opts, context) {
-  const image = docker.Image.from(opts, context)
+  const {image = docker.Image.from(opts, context)} = context
+
+  const sha = image.sha || opts.build_id
+  const sha256 = image.sha256 || opts.build_id
+
+  actions.setOutput('docker_image', image.repo)
+  actions.setOutput('docker_image_build_id', opts.build_id)
+  actions.setOutput('docker_image_sha_short', sha)
+  actions.setOutput('docker_image_sha_long', sha256)
+
+  actions.exportVariable('SEMANTIC_RELEASE_DOCKER_IMAGE', image.repo)
+  actions.exportVariable('SEMANTIC_RELEASE_DOCKER_IMAGE_BUILD_ID', opts.build_id)
+  actions.exportVariable('SEMANTIC_RELEASE_DOCKER_IMAGE_SHA_SHORT', sha)
+  actions.exportVariable('SEMANTIC_RELEASE_DOCKER_IMAGE_SHA_LONG', sha256)
   await image.push()
 }

test/unit/docker/image.js

@@ -348,6 +348,7 @@ test('Image', async (t) => {
 
     tt.notOk(img.sha, 'no show before build')
     const sha = await img.build()
+    tt.ok(sha, 'sha value returned from build function')
     tt.equal(sha, img.sha, 'image sha set after build')
     const {stdout} = await execa('docker', ['run', '--rm', img.name, 'ls', '-1'])
     tt.same(