Add metadata output

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

README.md

@@ -21,6 +21,7 @@ ___
 * [Usage](#usage)
 * [Customizing](#customizing)
   * [inputs](#inputs)
+  * [outputs](#outputs)
 * [Keep up-to-date with GitHub Dependabot](#keep-up-to-date-with-github-dependabot)
 
 ## Usage
@@ -88,6 +89,14 @@ Following inputs can be used as `step.with` keys
 | `push`           | Bool     | Push is a shorthand for `--set=*.output=type=registry` (default `false`) |
 | `set`            | List     | List of [targets values to override](https://github.com/docker/buildx/blob/master/docs/reference/buildx_bake.md#set) (eg: `targetpattern.key=value`) |
 
+### outputs
+
+Following outputs are available
+
+| Name              | Type    | Description                           |
+|-------------------|---------|---------------------------------------|
+| `metadata`        | JSON    | Build result metadata |
+
 ## Keep up-to-date with GitHub Dependabot
 
 Since [Dependabot](https://docs.github.com/en/github/administering-a-repository/keeping-your-actions-up-to-date-with-github-dependabot)

__tests__/buildx.test.ts

@@ -1,6 +1,38 @@
+import * as fs from 'fs';
+import * as path from 'path';
 import * as semver from 'semver';
-import * as buildx from '../src/buildx';
 import * as exec from '@actions/exec';
+import * as buildx from '../src/buildx';
+import * as context from '../src/context';
+
+const tmpNameSync = path.join('/tmp/.docker-bake-jest', '.tmpname-jest').split(path.sep).join(path.posix.sep);
+const metadata = `{
+  "containerimage.config.digest": "sha256:059b68a595b22564a1cbc167af369349fdc2ecc1f7bc092c2235cbf601a795fd",
+  "containerimage.digest": "sha256:b09b9482c72371486bb2c1d2c2a2633ed1d0b8389e12c8d52b9e052725c0c83c"
+}`;
+
+jest.spyOn(context, 'tmpDir').mockImplementation((): string => {
+  const tmpDir = path.join('/tmp/.docker-bake-jest').split(path.sep).join(path.posix.sep);
+  if (!fs.existsSync(tmpDir)) {
+    fs.mkdirSync(tmpDir, {recursive: true});
+  }
+  return tmpDir;
+});
+
+jest.spyOn(context, 'tmpNameSync').mockImplementation((): string => {
+  return tmpNameSync;
+});
+
+describe('getMetadata', () => {
+  it('matches', async () => {
+    const metadataFile = await buildx.getMetadataFile();
+    console.log(`metadataFile: ${metadataFile}`);
+    await fs.writeFileSync(metadataFile, metadata);
+    const expected = await buildx.getMetadata();
+    console.log(`metadata: ${expected}`);
+    expect(expected).toEqual(metadata);
+  });
+});
 
 describe('isAvailable', () => {
   const execSpy: jest.SpyInstance = jest.spyOn(exec, 'getExecOutput');

action.yml

@@ -36,6 +36,10 @@ inputs:
     description: "List of targets values to override (eg. targetpattern.key=value)"
     required: false
 
+outputs:
+  metadata:
+    description: 'Build result metadata'
+
 runs:
   using: 'node12'
   main: 'dist/index.js'

package.json

@@ -31,7 +31,8 @@
     "@actions/core": "^1.5.0",
     "@actions/exec": "^1.1.0",
     "csv-parse": "^4.16.2",
-    "semver": "^7.3.5"
+    "semver": "^7.3.5",
+    "tmp": "^0.2.1"
   },
   "devDependencies": {
     "@types/jest": "^26.0.23",

src/buildx.ts

@@ -1,6 +1,22 @@
+import fs from 'fs';
+import path from 'path';
 import * as semver from 'semver';
 import * as exec from '@actions/exec';
 
+import * as context from './context';
+
+export async function getMetadataFile(): Promise<string> {
+  return path.join(context.tmpDir(), 'metadata-file').split(path.sep).join(path.posix.sep);
+}
+
+export async function getMetadata(): Promise<string | undefined> {
+  const metadataFile = await getMetadataFile();
+  if (!fs.existsSync(metadataFile)) {
+    return undefined;
+  }
+  return fs.readFileSync(metadataFile, {encoding: 'utf-8'});
+}
+
 export async function isAvailable(): Promise<Boolean> {
   return await exec
     .getExecOutput('docker', ['buildx'], {
@@ -36,3 +52,7 @@ export function parseVersion(stdout: string): string {
   }
   return matches[1];
 }
+
+export function satisfies(version: string, range: string): boolean {
+  return semver.satisfies(version, range) || /^[0-9a-f]{7}$/.exec(version) !== null;
+}

src/context.ts

@@ -1,8 +1,14 @@
 import csvparse from 'csv-parse/lib/sync';
+import * as fs from 'fs';
+import * as os from 'os';
+import * as path from 'path';
+import * as tmp from 'tmp';
 import * as buildx from './buildx';
 import * as core from '@actions/core';
 import {issueCommand} from '@actions/core/lib/command';
 
+let _tmpDir: string;
+
 export interface Inputs {
   builder: string;
   files: string[];
@@ -14,6 +20,17 @@ export interface Inputs {
   set: string[];
 }
 
+export function tmpDir(): string {
+  if (!_tmpDir) {
+    _tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'docker-build-push-')).split(path.sep).join(path.posix.sep);
+  }
+  return _tmpDir;
+}
+
+export function tmpNameSync(options?: tmp.TmpNameOptions): string {
+  return tmp.tmpNameSync(options);
+}
+
 export async function getInputs(): Promise<Inputs> {
   return {
     builder: core.getInput('builder'),
@@ -43,6 +60,9 @@ async function getBakeArgs(inputs: Inputs, buildxVersion: string): Promise<Array
   await asyncForEach(inputs.set, async set => {
     args.push('--set', set);
   });
+  if (buildx.satisfies(buildxVersion, '>=0.6.0')) {
+    args.push('--metadata-file', await buildx.getMetadataFile());
+  }
   return args;
 }
 

src/main.ts

@@ -1,5 +1,7 @@
+import * as fs from 'fs';
 import * as buildx from './buildx';
 import * as context from './context';
+import * as stateHelper from './state-helper';
 import * as core from '@actions/core';
 import * as exec from '@actions/exec';
 
@@ -14,6 +16,7 @@ async function run(): Promise<void> {
       core.setFailed(`Docker buildx is required. See https://github.com/docker/setup-buildx-action to set up buildx.`);
       return;
     }
+    stateHelper.setTmpDir(context.tmpDir());
 
     const bxVersion = await buildx.getVersion();
     const inputs: context.Inputs = await context.getInputs();
@@ -32,9 +35,29 @@ async function run(): Promise<void> {
           throw new Error(`buildx bake failed with: ${res.stderr.match(/(.*)\s*$/)![0].trim()}`);
         }
       });
+
+    await core.group(`Setting outputs`, async () => {
+      const metadata = await buildx.getMetadata();
+      if (metadata) {
+        core.info(`metadata=${metadata}`);
+        context.setOutput('metadata', metadata);
+      }
+    });
   } catch (error) {
     core.setFailed(error.message);
   }
 }
 
-run();
+async function cleanup(): Promise<void> {
+  if (stateHelper.tmpDir.length > 0) {
+    core.startGroup(`Removing temp folder ${stateHelper.tmpDir}`);
+    fs.rmdirSync(stateHelper.tmpDir, {recursive: true});
+    core.endGroup();
+  }
+}
+
+if (!stateHelper.IsPost) {
+  run();
+} else {
+  cleanup();
+}

src/state-helper.ts

@@ -0,0 +1,12 @@
+import * as core from '@actions/core';
+
+export const IsPost = !!process.env['STATE_isPost'];
+export const tmpDir = process.env['STATE_tmpDir'] || '';
+
+export function setTmpDir(tmpDir: string) {
+  core.saveState('tmpDir', tmpDir);
+}
+
+if (!IsPost) {
+  core.saveState('isPost', 'true');
+}

yarn.lock

@@ -3244,6 +3244,13 @@ throat@^5.0.0:
   resolved "https://registry.yarnpkg.com/throat/-/throat-5.0.0.tgz#c5199235803aad18754a667d659b5e72ce16764b"
   integrity sha512-fcwX4mndzpLQKBS1DVYhGAcYaYt7vsHNIvQV+WXMvnow5cgjPphq5CaayLaGsjRdSCKZFNGt7/GYAuXaNOiYCA==
 
+tmp@^0.2.1:
+  version "0.2.1"
+  resolved "https://registry.yarnpkg.com/tmp/-/tmp-0.2.1.tgz#8457fc3037dcf4719c251367a1af6500ee1ccf14"
+  integrity sha512-76SUhtfqR2Ijn+xllcI5P1oyannHNHByD80W1q447gU3mp9G9PSpGdWmjUOHRDPiHYacIk66W7ubDTuPF3BEtQ==
+  dependencies:
+    rimraf "^3.0.0"
+
 tmpl@1.0.x:
   version "1.0.4"
   resolved "https://registry.yarnpkg.com/tmpl/-/tmpl-1.0.4.tgz#23640dd7b42d00433911140820e5cf440e521dd1"