regctl: manifestGet

Signed-off-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>

__tests__/regclient/regctl.test.ts

@@ -20,6 +20,26 @@ import * as semver from 'semver';
 import {Exec} from '../../src/exec';
 import {Regctl} from '../../src/regclient/regctl';
 
+describe('manifestGet', () => {
+  // prettier-ignore
+  test.each([
+    ['moby/moby-bin:latest'],
+    ['crazymax/undock:latest'],
+    ['crazymax/diun:4.17.0'],
+  ])('given %p', async image => {
+    const regctl = new Regctl();
+    const manifest = await regctl.manifestGet({
+      image: image,
+    });
+    console.log(`${image}: ${JSON.stringify(manifest, null, 2)}`);
+    expect(manifest).not.toBeNull();
+    expect(manifest?.config).toBeDefined();
+    expect(manifest?.config.digest).not.toEqual('');
+    expect(manifest?.layers).toBeDefined();
+    expect(manifest?.layers.length).toBeGreaterThan(0);
+  });
+});
+
 describe('isAvailable', () => {
   it('checks regctl is available', async () => {
     const execSpy = jest.spyOn(Exec, 'getExecOutput');

src/regclient/regctl.ts

@@ -19,10 +19,17 @@ import * as semver from 'semver';
 
 import {Exec} from '../exec';
 
+import {Manifest} from '../types/oci/manifest';
+
 export interface RegctlOpts {
   binPath?: string;
 }
 
+export interface RegctlManifestGetOpts {
+  image: string;
+  platform?: string;
+}
+
 export class Regctl {
   private readonly binPath: string;
   private _version: string;
@@ -34,6 +41,18 @@ export class Regctl {
     this._versionOnce = false;
   }
 
+  public async manifestGet(opts: RegctlManifestGetOpts): Promise<Manifest> {
+    return await Exec.getExecOutput(this.binPath, ['manifest', 'get', opts.image, `--platform=${opts.platform ?? 'local'}`, `--format={{json .}}`], {
+      ignoreReturnCode: true,
+      silent: true
+    }).then(res => {
+      if (res.stderr.length > 0 && res.exitCode != 0) {
+        throw new Error(res.stderr.trim());
+      }
+      return <Manifest>JSON.parse(res.stdout.trim());
+    });
+  }
+
   public async isAvailable(): Promise<boolean> {
     const ok: boolean = await Exec.getExecOutput(this.binPath, [], {
       ignoreReturnCode: true,