[ci] Conditonal webpack bundle reports (#136215)

* [ci] Conditonal webpack bundle reports

* fix

* spacing

* \n

* fix file path

.buildkite/pipelines/pull_request/base.yml

@@ -75,10 +75,3 @@ steps:
       automatic:
         - exit_status: '-1'
           limit: 3
-
-  - command: .buildkite/scripts/steps/webpack_bundle_analyzer/build_and_upload.sh
-    label: 'Build Webpack Bundle Analyzer reports'
-    agents:
-      queue: c2-16
-    key: webpack_bundle_analyzer
-    timeout_in_minutes: 60

.buildkite/pipelines/pull_request/webpack_bundle_analyzer.yml

@@ -0,0 +1,7 @@
+steps:
+  - command: .buildkite/scripts/steps/webpack_bundle_analyzer/build_and_upload.sh
+    label: 'Build Webpack Bundle Analyzer reports'
+    agents:
+      queue: n2-4-spot
+    key: webpack_bundle_analyzer
+    timeout_in_minutes: 60

.buildkite/scripts/pipelines/pull_request/pipeline.ts

@@ -126,6 +126,10 @@ const uploadPipeline = (pipelineContent: string | object) => {
       pipeline.push(getPipeline('.buildkite/pipelines/pull_request/deploy_cloud.yml'));
     }
 
+    if (GITHUB_PR_LABELS.includes('ci:build-webpack-bundle-analyzer')) {
+      pipeline.push(getPipeline('.buildkite/pipelines/pull_request/webpack_bundle_analyzer.yml'));
+    }
+
     pipeline.push(getPipeline('.buildkite/pipelines/pull_request/post_build.yml'));
 
     uploadPipeline(pipeline.join('\n'));

.buildkite/scripts/steps/webpack_bundle_analyzer/build_and_upload.sh

@@ -4,6 +4,8 @@ set -euo pipefail
 
 .buildkite/scripts/bootstrap.sh
 
+export NODE_OPTIONS="--max-old-space-size=8192"
+
 node scripts/build_kibana_platform_plugins.js --dist --profile
 
 mkdir -p built_assets/webpack_bundle_analyzer