Merge pull request #14586 from maxm0rt/users/maxm0rt/gitlabartifact

[Gitlab] Allow Backstage to refer to Gitlab job artifacts and naive API urls

.changeset/rich-balloons-leave.md

@@ -0,0 +1,5 @@
+---
+'@backstage/backend-common': patch
+---
+
+Added the ability to understand Job Artifact URLs to the GitLab integration

packages/backend-common/src/reading/GitlabUrlReader.test.ts

@@ -574,4 +574,86 @@ describe('GitlabUrlReader', () => {
       ).rejects.toThrow(NotModifiedError);
     });
   });
+
+  describe('getGitlabFetchUrl', () => {
+    beforeEach(() => {
+      worker.use(
+        rest.get(
+          '*/api/v4/projects/group%2Fsubgroup%2Fproject',
+          (_, res, ctx) => res(ctx.status(200), ctx.json({ id: 12345 })),
+        ),
+      );
+    });
+    it('should fall back to getGitLabFileFetchUrl for blob urls', async () => {
+      await expect(
+        (gitlabProcessor as any).getGitlabFetchUrl(
+          'https://gitlab.com/group/subgroup/project/-/blob/branch/my/path/to/file.yaml',
+        ),
+      ).resolves.toEqual(
+        'https://gitlab.com/api/v4/projects/12345/repository/files/my%2Fpath%2Fto%2Ffile.yaml/raw?ref=branch',
+      );
+    });
+    it('should work for job artifact urls', async () => {
+      await expect(
+        (gitlabProcessor as any).getGitlabFetchUrl(
+          'https://gitlab.com/group/subgroup/project/-/jobs/artifacts/branch/raw/my/path/to/file.yaml?job=myJob',
+        ),
+      ).resolves.toEqual(
+        'https://gitlab.com/api/v4/projects/12345/jobs/artifacts/branch/raw/my/path/to/file.yaml?job=myJob',
+      );
+    });
+    it('should fail on unfamiliar or non-Gitlab urls', async () => {
+      await expect(
+        (gitlabProcessor as any).getGitlabFetchUrl(
+          'https://gitlab.com/some/random/endpoint',
+        ),
+      ).rejects.toThrow('Please provide full path to yaml file from GitLab');
+    });
+  });
+
+  describe('getGitlabArtifactFetchUrl', () => {
+    beforeEach(() => {
+      worker.use(
+        rest.get(
+          '*/api/v4/projects/group%2Fsubgroup%2Fproject',
+          (_, res, ctx) => res(ctx.status(200), ctx.json({ id: 12345 })),
+        ),
+      );
+      worker.use(
+        rest.get(
+          '*/api/v4/projects/groupA%2Fsubgroup%2Fproject',
+          (_, res, ctx) => res(ctx.status(404)),
+        ),
+      );
+    });
+    it('should reject urls that are not for the job artifacts API', async () => {
+      await expect(
+        (gitlabProcessor as any).getGitlabArtifactFetchUrl(
+          new URL('https://gitlab.com/some/url'),
+        ),
+      ).rejects.toThrow('Unable to process url as an GitLab artifact');
+    });
+    it('should work for job artifact urls', async () => {
+      await expect(
+        (gitlabProcessor as any).getGitlabArtifactFetchUrl(
+          new URL(
+            'https://gitlab.com/group/subgroup/project/-/jobs/artifacts/branch/raw/my/path/to/file.yaml?job=myJob',
+          ),
+        ),
+      ).resolves.toEqual(
+        new URL(
+          'https://gitlab.com/api/v4/projects/12345/jobs/artifacts/branch/raw/my/path/to/file.yaml?job=myJob',
+        ),
+      );
+    });
+    it('errors in mapping the project ID should be captured', async () => {
+      await expect(
+        (gitlabProcessor as any).getGitlabArtifactFetchUrl(
+          new URL(
+            'https://gitlab.com/groupA/subgroup/project/-/jobs/artifacts/branch/raw/my/path/to/file.yaml?job=myJob',
+          ),
+        ),
+      ).rejects.toThrow(/^Unable to translate GitLab artifact URL:/);
+    });
+  });
 });

packages/backend-common/src/reading/GitlabUrlReader.ts

@@ -73,7 +73,7 @@ export class GitlabUrlReader implements UrlReader {
     options?: ReadUrlOptions,
   ): Promise<ReadUrlResponse> {
     const { etag, signal } = options ?? {};
-    const builtUrl = await getGitLabFileFetchUrl(url, this.integration.config);
+    const builtUrl = await this.getGitlabFetchUrl(url);
 
     let response: Response;
     try {
@@ -256,4 +256,66 @@ export class GitlabUrlReader implements UrlReader {
     const { host, token } = this.integration.config;
     return `gitlab{host=${host},authed=${Boolean(token)}}`;
   }
+
+  private async getGitlabFetchUrl(target: string): Promise<string> {
+    // If the target is for a job artifact then go down that path
+    const targetUrl = new URL(target);
+    if (targetUrl.pathname.includes('/-/jobs/artifacts/')) {
+      return this.getGitlabArtifactFetchUrl(targetUrl).then(value =>
+        value.toString(),
+      );
+    }
+    // Default to the old behavior of assuming the url is for a file
+    return getGitLabFileFetchUrl(target, this.integration.config);
+  }
+
+  // convert urls of the form:
+  //    https://example.com/<namespace>/<project>/-/jobs/artifacts/<ref>/raw/<path_to_file>?job=<job_name>
+  // to urls of the form:
+  //    https://example.com/api/v4/projects/:id/jobs/artifacts/:ref_name/raw/*artifact_path?job=<job_name>
+  private async getGitlabArtifactFetchUrl(target: URL): Promise<URL> {
+    if (!target.pathname.includes('/-/jobs/artifacts/')) {
+      throw new Error('Unable to process url as an GitLab artifact');
+    }
+    try {
+      const [namespaceAndProject, ref] =
+        target.pathname.split('/-/jobs/artifacts/');
+      const projectPath = new URL(target);
+      projectPath.pathname = namespaceAndProject;
+      const projectId = await this.resolveProjectToId(projectPath);
+      const relativePath = getGitLabIntegrationRelativePath(
+        this.integration.config,
+      );
+      const newUrl = new URL(target);
+      newUrl.pathname = `${relativePath}/api/v4/projects/${projectId}/jobs/artifacts/${ref}`;
+      return newUrl;
+    } catch (e) {
+      throw new Error(
+        `Unable to translate GitLab artifact URL: ${target}, ${e}`,
+      );
+    }
+  }
+
+  private async resolveProjectToId(pathToProject: URL): Promise<number> {
+    let project = pathToProject.pathname;
+    // Check relative path exist and remove it if so
+    const relativePath = getGitLabIntegrationRelativePath(
+      this.integration.config,
+    );
+    if (relativePath) {
+      project = project.replace(relativePath, '');
+    }
+    // Trim an initial / if it exists
+    project = project.replace(/^\//, '');
+    const result = await fetch(
+      `${
+        pathToProject.origin
+      }${relativePath}/api/v4/projects/${encodeURIComponent(project)}`,
+    );
+    const data = await result.json();
+    if (!result.ok) {
+      throw new Error(`Gitlab error: ${data.error}, ${data.error_description}`);
+    }
+    return Number(data.id);
+  }
 }