Add metadata output

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

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');
+}