feat(pipedream): allow rollback final_pipeline override

README.md

@@ -149,6 +149,19 @@ local pipedream_config = {
     stage: 'example_stage',
     # The elastic agent profile to run the rollback pipeline as
     elastic_profile_id: 'example_profile',
+    # (Optional) The stage on the source-of-truth pipeline that the rollback
+    # material watches. Defaults to that pipeline's final stage
+    # (`pipeline-complete`). Set to an earlier stage (e.g. 'deploy-primary')
+    # so a SHA becomes rollback-eligible without waiting for the trailing
+    # noop stage.
+    # final_stage: 'deploy-primary',
+    # (Optional) Which group pipeline is the source of truth for rollback
+    # revisions. Defaults to the last group in the chain (e.g. `st`). Set to a
+    # group name (e.g. 'us') to anchor rollback eligibility on an earlier group
+    # when the tail group is flaky and would otherwise starve the rollback
+    # target pool. Trade-off: an upstream-anchored target may not have been
+    # validated on the downstream groups the rollback then deploys it to.
+    # final_pipeline: 'us',
   },
 
   # Set to true to auto-deploy changes (defaults to true)

libs/pipedream.libsonnet

@@ -137,7 +137,22 @@ local pipedream_trigger_pipeline(pipedream_config) =
 local pipedream_rollback_pipeline(pipedream_config, service_pipelines, trigger_pipeline) =
   if std.objectHas(pipedream_config, 'rollback') then
     local name = pipedream_config.name;
-    local final_pipeline = service_pipelines[std.length(service_pipelines) - 1];
+    // The rollback material's "source of truth" pipeline. By default this is
+    // the last pipeline in the chain (the final group, e.g. `st`), so a SHA is
+    // only rollback-eligible once it has deployed all the way through. Set
+    // `rollback.final_pipeline` to a group name (e.g. 'us') to anchor rollback
+    // eligibility on an earlier group instead — useful when the tail group is
+    // flaky and would otherwise starve the rollback target pool. Note the
+    // trade-off: anchoring upstream means a rollback target may not have been
+    // validated on the downstream groups it then gets deployed to.
+    local final_pipeline =
+      if std.objectHas(pipedream_config.rollback, 'final_pipeline') then
+        local target = pipeline_name(name, pipedream_config.rollback.final_pipeline);
+        local matches = std.filter(function(p) p.name == target, service_pipelines);
+        assert std.length(matches) > 0 : "Rollback final_pipeline '" + target + "' not found in service pipelines";
+        matches[0]
+      else
+        service_pipelines[std.length(service_pipelines) - 1];
 
     // Rollbacks work by calling two devinfra-deployment-infra scripts:
     //    gocd-pause-and-cancel-pipelines

test/pipedream.js

@@ -150,6 +150,40 @@ test("rollback: invalid final stage errors", (t) => {
   );
 });
 
+test("rollback: final_pipeline anchors material on an earlier group", async (t) => {
+  const got = await render_fixture(
+    "pipedream/rollback-final-pipeline-override.jsonnet",
+    false,
+  );
+
+  const r = got.pipelines["rollback-example"];
+  t.truthy(r);
+  // Material watches the `us` group's final stage, not the default last group.
+  t.truthy(r.materials["deploy-example-us-pipeline-complete"]);
+  t.is(
+    r.materials["deploy-example-us-pipeline-complete"].pipeline,
+    "deploy-example-us",
+  );
+  t.is(
+    r.materials["deploy-example-us-pipeline-complete"].stage,
+    "pipeline-complete",
+  );
+  // Rollback still re-runs every region pipeline.
+  t.truthy(
+    r.environment_variables.REGION_PIPELINE_FLAGS.includes("deploy-example-st"),
+  );
+});
+
+test("rollback: unknown final_pipeline errors", (t) => {
+  const err = t.throws(() =>
+    get_fixture_content(
+      "pipedream/rollback-bad-final-pipeline.failing.jsonnet",
+      false,
+    ),
+  );
+  t.true(err.message.includes("not found in service pipelines"));
+});
+
 test("conflicting stage properties across regions errors", (t) => {
   const err = t.throws(() =>
     get_fixture_content(

test/testdata/fixtures/pipedream/rollback-bad-final-pipeline.failing.jsonnet

@@ -0,0 +1,43 @@
+local pipedream = import '../../../../libs/pipedream.libsonnet';
+
+// final_pipeline names a group that doesn't exist -> should error at compile
+// time rather than producing a rollback pipeline with a dangling material.
+
+local pipedream_config = {
+  name: 'example',
+  auto_deploy: true,
+  rollback: {
+    material_name: 'example_repo',
+    stage: 'deploy',
+    elastic_profile_id: 'example',
+    final_pipeline: 'this-group-does-not-exist',
+  },
+};
+
+local sample = {
+  pipeline(region):: {
+    materials: {
+      example_repo: {
+        git: 'git@github.com:getsentry/example.git',
+        branch: 'master',
+        destination: 'example',
+      },
+    },
+    stages: [
+      {
+        deploy: {
+          jobs: {
+            deploy: {
+              elastic_profile_id: 'example',
+              tasks: [
+                { script: './deploy.sh --region=' + region },
+              ],
+            },
+          },
+        },
+      },
+    ],
+  },
+};
+
+pipedream.render(pipedream_config, sample.pipeline)

test/testdata/fixtures/pipedream/rollback-final-pipeline-override.jsonnet

@@ -0,0 +1,44 @@
+local pipedream = import '../../../../libs/pipedream.libsonnet';
+
+// Anchor the rollback material on the `us` group instead of the default last
+// group (`st`). A SHA becomes rollback-eligible once `us` reaches its final
+// stage, so a flaky tail group no longer starves the rollback target pool.
+
+local pipedream_config = {
+  name: 'example',
+  auto_deploy: true,
+  rollback: {
+    material_name: 'example_repo',
+    stage: 'deploy',
+    elastic_profile_id: 'example',
+    final_pipeline: 'us',
+  },
+};
+
+local sample = {
+  pipeline(region):: {
+    materials: {
+      example_repo: {
+        git: 'git@github.com:getsentry/example.git',
+        branch: 'master',
+        destination: 'example',
+      },
+    },
+    stages: [
+      {
+        deploy: {
+          jobs: {
+            deploy: {
+              elastic_profile_id: 'example',
+              tasks: [
+                { script: './deploy.sh --region=' + region },
+              ],
+            },
+          },
+        },
+      },
+    ],
+  },
+};
+
+pipedream.render(pipedream_config, sample.pipeline)