Enable non-org autoscaler to read scale-config from any repo

terraform-aws-github-runner/modules/runners/lambdas/runners/src/scale-runners/config.test.ts

@@ -193,7 +193,7 @@ describe('Config', () => {
     expect(Config.Instance.mustHaveIssuesLabels).toEqual([]);
     expect(Config.Instance.runnerGroupName).toBeUndefined();
     expect(Config.Instance.runnersExtraLabels).toBeUndefined();
-    expect(Config.Instance.scaleConfigRepo).toEqual('test-infra');
+    expect(Config.Instance.scaleConfigRepo).toEqual('');
     expect(Config.Instance.scaleConfigRepoPath).toEqual('.github/scale-config.yml');
     expect(Config.Instance.secretsManagerSecretsId).toBeUndefined();
     expect(Config.Instance.shuffledAwsRegionInstances).toEqual([]);

terraform-aws-github-runner/modules/runners/lambdas/runners/src/scale-runners/config.ts

@@ -97,7 +97,7 @@ export class Config {
     this.runnerGroupName = process.env.RUNNER_GROUP_NAME;
     this.runnersExtraLabels = process.env.RUNNER_EXTRA_LABELS;
     /* istanbul ignore next */
-    this.scaleConfigRepo = process.env.SCALE_CONFIG_REPO || 'test-infra';
+    this.scaleConfigRepo = process.env.SCALE_CONFIG_REPO || '';
     this.scaleConfigRepoPath = process.env.SCALE_CONFIG_REPO_PATH || '.github/scale-config.yml';
     this.secretsManagerSecretsId = process.env.SECRETSMANAGER_SECRETS_ID;
     this.sSMParamCleanupAgeDays = Number(process.env.SSM_PARAM_CLEANUP_AGE_DAYS || '7');

terraform-aws-github-runner/modules/runners/lambdas/runners/src/scale-runners/scale-down.test.ts

@@ -1256,57 +1256,118 @@ describe('scale-down', () => {
     describe('repo runners', () => {
       const runnerType = 'runnerTypeDef';
       const owner = 'the-org';
-      const repo: Repo = {
+      const runnerRepo: Repo = {
         owner: owner,
         repo: 'a-repo',
       };
-      const repoKey = `${owner}/a-repo`;
+      const runnerRepoKey = `${owner}/a-repo`;
 
-      beforeEach(() => {
-        jest.spyOn(Config, 'Instance', 'get').mockImplementation(
-          () =>
-            ({
-              ...baseConfig,
-              enableOrganizationRunners: false,
-            } as unknown as Config),
-        );
-      });
+      describe('When no scaleConfigRepo is set, the runner repo is used as the source for scale config', () => {
 
-      it('is_ephemeral === undefined', async () => {
-        const mockedGetRunnerTypes = mocked(getRunnerTypes);
+        beforeEach(() => {
+          jest.spyOn(Config, 'Instance', 'get').mockImplementation(
+            () =>
+              ({
+                ...baseConfig,
+                enableOrganizationRunners: false,
+              } as unknown as Config),
+          );
+        });
 
-        mockedGetRunnerTypes.mockResolvedValueOnce(new Map([[runnerType, {} as RunnerType]]));
+        it('is_ephemeral === undefined', async () => {
+          const mockedGetRunnerTypes = mocked(getRunnerTypes);
 
-        expect(await isEphemeralRunner({ runnerType: runnerType, repo: repoKey } as RunnerInfo, metrics)).toEqual(
-          false,
-        );
+          mockedGetRunnerTypes.mockResolvedValueOnce(new Map([[runnerType, {} as RunnerType]]));
 
-        expect(mockedGetRunnerTypes).toBeCalledTimes(1);
-        expect(mockedGetRunnerTypes).toBeCalledWith(repo, metrics);
-      });
+          expect(await isEphemeralRunner({ runnerType: runnerType, repo: runnerRepoKey } as RunnerInfo, metrics)).toEqual(
+            false,
+          );
 
-      it('is_ephemeral === true', async () => {
-        const mockedGetRunnerTypes = mocked(getRunnerTypes);
+          expect(mockedGetRunnerTypes).toBeCalledTimes(1);
+          expect(mockedGetRunnerTypes).toBeCalledWith(runnerRepo, metrics);
+        });
 
-        mockedGetRunnerTypes.mockResolvedValueOnce(new Map([[runnerType, { is_ephemeral: true } as RunnerType]]));
+        it('is_ephemeral === true', async () => {
+          const mockedGetRunnerTypes = mocked(getRunnerTypes);
 
-        expect(await isEphemeralRunner({ runnerType: runnerType, repo: repoKey } as RunnerInfo, metrics)).toEqual(true);
+          mockedGetRunnerTypes.mockResolvedValueOnce(new Map([[runnerType, { is_ephemeral: true } as RunnerType]]));
 
-        expect(mockedGetRunnerTypes).toBeCalledTimes(1);
-        expect(mockedGetRunnerTypes).toBeCalledWith(repo, metrics);
+          expect(await isEphemeralRunner({ runnerType: runnerType, repo: runnerRepoKey } as RunnerInfo, metrics)).toEqual(true);
+
+          expect(mockedGetRunnerTypes).toBeCalledTimes(1);
+          expect(mockedGetRunnerTypes).toBeCalledWith(runnerRepo, metrics);
+        });
+
+        it('is_ephemeral === false', async () => {
+          const mockedGetRunnerTypes = mocked(getRunnerTypes);
+
+          mockedGetRunnerTypes.mockResolvedValueOnce(new Map([[runnerType, { is_ephemeral: false } as RunnerType]]));
+
+          expect(await isEphemeralRunner({ runnerType: runnerType, repo: runnerRepoKey } as RunnerInfo, metrics)).toEqual(
+            false,
+          );
+
+          expect(mockedGetRunnerTypes).toBeCalledTimes(1);
+          expect(mockedGetRunnerTypes).toBeCalledWith(runnerRepo, metrics);
+        });
       });
 
-      it('is_ephemeral === false', async () => {
-        const mockedGetRunnerTypes = mocked(getRunnerTypes);
+      describe("When a scaleConfigRepo is set, it's used as the source for scale config", () => {
+        const centralRepoName = 'central-repo'; // to be the test-infra equivalent
+        const centralRepo: Repo = {
+          owner: owner,
+          repo: centralRepoName,
+        };
 
-        mockedGetRunnerTypes.mockResolvedValueOnce(new Map([[runnerType, { is_ephemeral: false } as RunnerType]]));
+        beforeEach(() => {
+          jest.spyOn(Config, 'Instance', 'get').mockImplementation(
+            () =>
+              ({
+                ...baseConfig,
+                enableOrganizationRunners: false,
+                scaleConfigRepo: centralRepoName,
+              } as unknown as Config),
+          );
+        });
+
+        it('is_ephemeral === undefined', async () => {
+          const mockedGetRunnerTypes = mocked(getRunnerTypes);
+
+          mockedGetRunnerTypes.mockResolvedValueOnce(new Map([[runnerType, {} as RunnerType]]));
+
+          expect(await isEphemeralRunner({ runnerType: runnerType, repo: runnerRepoKey } as RunnerInfo, metrics)).toEqual(
+            false,
+          );
+
+          expect(mockedGetRunnerTypes).toBeCalledTimes(1);
+          expect(mockedGetRunnerTypes).toBeCalledWith(centralRepo, metrics);
+        });
+
+        it('is_ephemeral === true', async () => {
+          const mockedGetRunnerTypes = mocked(getRunnerTypes);
+
+          mockedGetRunnerTypes.mockResolvedValueOnce(new Map([[runnerType, { is_ephemeral: true } as RunnerType]]));
+
+          expect(await isEphemeralRunner({ runnerType: runnerType, repo: runnerRepoKey } as RunnerInfo, metrics)).toEqual(true);
+
+          expect(mockedGetRunnerTypes).toBeCalledTimes(1);
+          expect(mockedGetRunnerTypes).toBeCalledWith(centralRepo, metrics);
+        });
+
+        it('is_ephemeral === false', async () => {
+          const mockedGetRunnerTypes = mocked(getRunnerTypes);
+
+          mockedGetRunnerTypes.mockResolvedValueOnce(new Map([[runnerType, { is_ephemeral: false } as RunnerType]]));
+
+          expect(await isEphemeralRunner({ runnerType: runnerType, repo: runnerRepoKey } as RunnerInfo, metrics)).toEqual(
+            false,
+          );
+
+          expect(mockedGetRunnerTypes).toBeCalledTimes(1);
+          expect(mockedGetRunnerTypes).toBeCalledWith(centralRepo, metrics);
+        });
 
-        expect(await isEphemeralRunner({ runnerType: runnerType, repo: repoKey } as RunnerInfo, metrics)).toEqual(
-          false,
-        );
 
-        expect(mockedGetRunnerTypes).toBeCalledTimes(1);
-        expect(mockedGetRunnerTypes).toBeCalledWith(repo, metrics);
       });
     });
   });

terraform-aws-github-runner/modules/runners/lambdas/runners/src/scale-runners/scale-down.ts

@@ -373,7 +373,7 @@ export async function isEphemeralRunner(ec2runner: RunnerInfo, metrics: ScaleDow
   }
 
   const repo: Repo = (() => {
-    if (Config.Instance.enableOrganizationRunners) {
+    if (Config.Instance.scaleConfigRepo) {
       return {
         owner: ec2runner.org !== undefined ? (ec2runner.org as string) : getRepo(ec2runner.repo as string).owner,
         repo: Config.Instance.scaleConfigRepo,

terraform-aws-github-runner/modules/runners/lambdas/runners/src/scale-runners/scale-up.ts

@@ -60,7 +60,7 @@ export async function scaleUp(
   const runnerTypes = await getRunnerTypes(
     {
       owner: repo.owner,
-      repo: Config.Instance.enableOrganizationRunners ? Config.Instance.scaleConfigRepo : repo.repo,
+      repo: Config.Instance.scaleConfigRepo || repo.repo,
     },
     metrics,
   );

terraform-aws-github-runner/modules/runners/scale-down.tf

@@ -26,6 +26,16 @@ resource "aws_lambda_function" "scale_down" {
   tags              = local.tags
   memory_size       = 2048
 
+  lifecycle {
+    precondition {
+      # Enforce that a value for scale_config_repo is set when enable_organization_runners is set to true.
+      # Setting the value is optional when not using organization runners since we'll default to the
+      # job's repository.
+      condition     = var.enable_organization_runners == true ? var.scale_config_repo != "" : true
+      error_message = "scale_config_repo is required when enable_organization_runners is set to true"
+    }
+  }
+
   environment {
     variables = {
       AWS_REGION_INSTANCES            = join(",", var.aws_region_instances)

terraform-aws-github-runner/modules/runners/scale-up.tf

@@ -28,6 +28,16 @@ resource "aws_lambda_function" "scale_up" {
   memory_size                    = 2048
   publish                        = true
 
+  lifecycle {
+    precondition {
+      # Enforce that a value for scale_config_repo is set when enable_organization_runners is set to true.
+      # Setting the value is optional when not using organization runners since we'll default to the
+      # job's repository.
+      condition     = var.enable_organization_runners == true ? var.scale_config_repo != "" : true
+      error_message = "scale_config_repo is required when enable_organization_runners is set to true"
+    }
+  }
+
   environment {
     variables = {
       CANT_HAVE_ISSUES_LABELS              = join(",", var.cant_have_issues_labels)

terraform-aws-github-runner/variables.tf

@@ -346,8 +346,8 @@ variable "cant_have_issues_labels" {
 }
 
 variable "scale_config_repo" {
-  description = "Repository to fetch scale config from if `enable_organization_runners` is set to true. Otherwise the job's repo will be used"
-  default     = "" # Internally defaults to 'test-infra'
+  description = "Repository to fetch scale config from.  Optional if `enable_organization_runners` is set to false, in which case the job's repo will be used"
+  default     = ""
   type        = string
 }