regctl: blobGet func

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

__tests__/regclient/regctl.test.ts

@@ -20,18 +20,19 @@ import * as semver from 'semver';
 import {Exec} from '../../src/exec';
 import {Regctl} from '../../src/regclient/regctl';
 
+import {Image} from '../../src/types/oci/config';
+
 describe('manifestGet', () => {
   // prettier-ignore
   test.each([
-    ['moby/moby-bin:latest'],
+    ['moby/moby-bin:28.1.0-rc.2'],
-    ['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}: ${JSON.stringify(manifest, null, 2)}`);
+    console.log(`${image} manifest: ${JSON.stringify(manifest, null, 2)}`);
     expect(manifest).not.toBeNull();
     expect(manifest?.config).toBeDefined();
     expect(manifest?.config.digest).not.toEqual('');
@@ -40,6 +41,48 @@ describe('manifestGet', () => {
   });
 });
 
+describe('blobGet', () => {
+  // prettier-ignore
+  test.each([
+    ['moby/moby-bin', 'sha256:234fccbd13fde0ba978a19f728cbdc67e29bc76247ac560822bb6ae5236c0bf0'],
+    ['crazymax/diun', 'sha256:1e4881f66e0ec0f1710b837002107050bbbc0a231d8a42d7f422b56a139900bb'],
+  ])('given %p', async (repo, digest) => {
+    const regctl = new Regctl();
+    const blob = await regctl.blobGet({
+      repository: repo,
+      digest: digest
+    });
+    expect(blob).toBeDefined();
+    console.log(`${repo}:@${digest} blob: ${JSON.stringify(JSON.parse(blob), null, 2)}`);
+  });
+});
+
+describe('image config', () => {
+  // prettier-ignore
+  test.each([
+    ['moby/moby-bin:28.1.0-rc.2'],
+    ['crazymax/diun:4.17.0'],
+  ])('given %p', async image => {
+    const regctl = new Regctl();
+    const manifest = await regctl.manifestGet({
+      image: image,
+    });
+    expect(manifest).not.toBeNull();
+    expect(manifest?.config).toBeDefined();
+    expect(manifest?.config.digest).not.toEqual('');
+    const blob = await regctl.blobGet({
+      repository: image, // image works as well
+      digest: manifest?.config.digest
+    });
+    const imageConfig = <Image>JSON.parse(blob);
+    console.log(`${image} config: ${JSON.stringify(imageConfig, null, 2)}`);
+    expect(imageConfig).not.toBeNull();
+    expect(imageConfig.config).toBeDefined();
+    expect(imageConfig?.config?.Labels).toBeDefined();
+    expect(Object.keys(imageConfig?.config?.Labels || {}).length).toBeGreaterThan(0);
+  });
+});
+
 describe('isAvailable', () => {
   it('checks regctl is available', async () => {
     const execSpy = jest.spyOn(Exec, 'getExecOutput');

src/regclient/regctl.ts

@@ -25,6 +25,11 @@ export interface RegctlOpts {
   binPath?: string;
 }
 
+export interface RegctlBlobGetOpts {
+  repository: string;
+  digest: string;
+}
+
 export interface RegctlManifestGetOpts {
   image: string;
   platform?: string;
@@ -41,6 +46,19 @@ export class Regctl {
     this._versionOnce = false;
   }
 
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  public async blobGet(opts: RegctlBlobGetOpts): Promise<any> {
+    return await Exec.getExecOutput(this.binPath, ['blob', 'get', opts.repository, opts.digest], {
+      ignoreReturnCode: true,
+      silent: true
+    }).then(res => {
+      if (res.stderr.length > 0 && res.exitCode != 0) {
+        throw new Error(res.stderr.trim());
+      }
+      return res.stdout;
+    });
+  }
+
   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,