Add bake-file output (#36)

Co-authored-by: CrazyMax <crazy-max@users.noreply.github.com>

src/context.ts

@@ -1,5 +1,10 @@
 import csvparse from 'csv-parse/lib/sync';
 import * as core from '@actions/core';
+import * as fs from 'fs';
+import * as os from 'os';
+import * as path from 'path';
+
+let _tmpDir: string;
 
 export interface Inputs {
   images: string[];
@@ -19,6 +24,13 @@ export interface Inputs {
   githubToken: string;
 }
 
+export function tmpDir(): string {
+  if (!_tmpDir) {
+    _tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'ghaction-docker-meta-')).split(path.sep).join(path.posix.sep);
+  }
+  return _tmpDir;
+}
+
 export function getInputs(): Inputs {
   return {
     images: getInputList('images'),

src/main.ts

@@ -1,3 +1,4 @@
+import * as fs from 'fs';
 import {getInputs, Inputs} from './context';
 import * as github from './github';
 import {Meta, Version} from './meta';
@@ -33,6 +34,7 @@ async function run() {
     core.endGroup();
     core.setOutput('version', version.main || '');
 
+    // Docker tags
     const tags: Array<string> = meta.tags();
     core.startGroup(`Docker tags`);
     for (let tag of tags) {
@@ -41,6 +43,7 @@ async function run() {
     core.endGroup();
     core.setOutput('tags', tags.join(inputs.sepTags));
 
+    // Docker labels
     const labels: Array<string> = meta.labels();
     core.startGroup(`Docker labels`);
     for (let label of labels) {
@@ -48,6 +51,13 @@ async function run() {
     }
     core.endGroup();
     core.setOutput('labels', labels.join(inputs.sepLabels));
+
+    // Bake definition file
+    const bakeFile: string = meta.bakeFile();
+    core.startGroup(`Bake definition file`);
+    core.info(fs.readFileSync(bakeFile, 'utf8'));
+    core.endGroup();
+    core.setOutput('bake-file', bakeFile);
   } catch (error) {
     core.setFailed(error.message);
   }

src/meta.ts

@@ -1,7 +1,9 @@
 import * as handlebars from 'handlebars';
+import * as fs from 'fs';
+import * as path from 'path';
 import moment from 'moment';
 import * as semver from 'semver';
-import {Inputs} from './context';
+import {Inputs, tmpDir} from './context';
 import * as core from '@actions/core';
 import {Context} from '@actions/github/lib/context';
 import {ReposGetResponseData} from '@octokit/types';
@@ -143,4 +145,34 @@ export class Meta {
     labels.push(...this.inputs.labelCustom);
     return labels;
   }
+
+  public bakeFile(): string {
+    let jsonLabels = {};
+    for (let label of this.labels()) {
+      const matches = label.match(/([^=]*)=(.*)/);
+      if (!matches) {
+        continue;
+      }
+      jsonLabels[matches[1]] = matches[2];
+    }
+
+    const bakeFile = path.join(tmpDir(), 'ghaction-docker-meta-bake.json').split(path.sep).join(path.posix.sep);
+    fs.writeFileSync(
+      bakeFile,
+      JSON.stringify(
+        {
+          target: {
+            'ghaction-docker-meta': {
+              tags: this.tags(),
+              labels: jsonLabels
+            }
+          }
+        },
+        null,
+        2
+      )
+    );
+
+    return bakeFile;
+  }
 }