[ci] mark PR stats as usable for metrics (#138297) (#138555)

(cherry picked from commit 92fb5dbafc)

Co-authored-by: Spencer <spencer@elastic.co>

.buildkite/pipeline-utils/ci-stats/client.ts

@@ -84,6 +84,9 @@ export class CiStatsClient {
         jenkinsJobId: process.env.BUILDKITE_BUILD_NUMBER,
         jenkinsUrl: process.env.BUILDKITE_BUILD_URL,
         prId: process.env.GITHUB_PR_NUMBER || null,
+        backfillJobIds: process.env.KIBANA_REUSABLE_BUILD_JOB_ID
+          ? [process.env.KIBANA_REUSABLE_BUILD_JOB_ID]
+          : [],
       },
     });
 
@@ -132,13 +135,12 @@ export class CiStatsClient {
     });
   };
 
-  getPrReport = async (buildId: string, backfillJobIds: string[] = []) => {
+  getPrReport = async (buildId: string) => {
     const resp = await this.request<CiStatsPrReport>({
-      path: `v3/pr_report`,
-      method: 'post',
-      body: {
+      method: 'GET',
+      path: `v2/pr_report`,
+      params: {
         buildId,
-        backfillJobIds,
       },
     });
 

.buildkite/pipelines/pull_request/base.yml

@@ -15,6 +15,30 @@ steps:
     if: "build.env('KIBANA_BUILD_ID') == null || build.env('KIBANA_BUILD_ID') == ''"
     timeout_in_minutes: 60
 
+  - command: .buildkite/scripts/steps/build_api_docs.sh
+    label: 'Build API Docs'
+    agents:
+      queue: n2-4-spot
+    key: build_api_docs
+    timeout_in_minutes: 60
+    retry:
+      automatic:
+        - exit_status: '-1'
+          limit: 3
+
+  - command: .buildkite/scripts/steps/ci_stats_ready.sh
+    label: Mark CI Stats as ready
+    agents:
+      queue: kibana-default
+    timeout_in_minutes: 10
+    depends_on:
+      - build
+      - build_api_docs
+    retry:
+      automatic:
+        - exit_status: '*'
+          limit: 1
+
   - command: .buildkite/scripts/steps/test/pick_test_group_run_order.sh
     label: 'Pick Test Group Run Order'
     agents:
@@ -61,14 +85,3 @@ steps:
     agents:
       queue: c2-8
     timeout_in_minutes: 60
-
-  - command: .buildkite/scripts/steps/build_api_docs.sh
-    label: 'Build API Docs'
-    agents:
-      queue: n2-4-spot
-    key: build_api_docs
-    timeout_in_minutes: 60
-    retry:
-      automatic:
-        - exit_status: '-1'
-          limit: 3