[9.0] [CI] Prefer local moon cache (#238109)

.buildkite/pipelines/on_merge.yml

@@ -17,6 +17,20 @@ steps:
           limit: 1
   - wait
 
+  - command: .buildkite/scripts/steps/store_cache.sh
+    label: Store Cache for build
+    timeout_in_minutes: 10
+    id: store_cache
+    soft_fail: true
+    depends_on:
+      - terrazzo-initial-pipeline-upload
+    agents:
+      image: family/kibana-ubuntu-2404
+      imageProject: elastic-images-prod
+      provider: gcp
+      machineType: n2-standard-2
+      diskSizeGb: 95
+
   - command: .buildkite/scripts/steps/on_merge_build_and_metrics.sh
     label: Build Kibana Distribution
     agents:

.buildkite/pipelines/pull_request/base.yml

@@ -2,12 +2,24 @@ steps:
   - command: .buildkite/scripts/lifecycle/pre_build.sh
     label: Pre-Build
     timeout_in_minutes: 10
+    id: pre_build
     agents:
       machineType: n2-standard-2
       diskSizeGb: 100
 
   - wait
 
+  - command: .buildkite/scripts/steps/store_cache.sh
+    label: Store Cache for build
+    timeout_in_minutes: 10
+    id: store_cache
+    soft_fail: true
+    depends_on:
+      - terrazzo-initial-pipeline-upload
+    agents:
+      machineType: n2-standard-2
+      diskSizeGb: 95
+
   - command: .buildkite/scripts/steps/build_kibana.sh
     label: Build Kibana Distribution
     agents:

.buildkite/scripts/bootstrap.sh

@@ -23,10 +23,16 @@ if [[ "$(pwd)" != *"/local-ssd/"* && "$(pwd)" != "/dev/shm"* ]]; then
     echo "Using ~/.kibana/.yarn-local-mirror as a starting point"
     mv ~/.kibana/.yarn-local-mirror ./
   fi
-  if [[ -d ~/.kibana-moon-cache ]]; then
+  # Check if there's a cache artifact uploaded from a previous step
+  if (buildkite-agent artifact download --step "store_cache" "moon-cache.tar.gz" ~/); then
+    echo "Found moon-cache.tar.gz artifact, extracting to ./.moon/cache"
+    mkdir -p ./.moon/cache
+    echo "Extracting moon-cache.tar.gz to ./.moon/cache"
+    tar -xzf ~/moon-cache.tar.gz -C ./
+  elif [[ -d ~/.kibana-moon-cache ]]; then
     echo "Using ~/.moon/cache as a starting point"
     mkdir -p ./.moon/cache
-    mv ~/.kibana-moon-cache ./.moon/cache
+    mv ~/.kibana-moon-cache/* ./.moon/cache
   fi
 fi
 

.buildkite/scripts/steps/store_cache.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+source .buildkite/scripts/common/util.sh
+
+export MOON_CACHE=write
+.buildkite/scripts/bootstrap.sh
+echo "--- Archive moon cache"
+if [[ ! -d .moon/cache ]]; then
+  echo "No moon cache directory found, skipping archive"
+  exit 0
+else
+  tar -czf ~/moon-cache.tar.gz .moon/cache || echo "Failed to archive moon cache"
+  cd ~/
+  buildkite-agent artifact upload moon-cache.tar.gz || echo "Failed to upload moon cache"
+  echo "Moon cache archived as moon-cache.tar.gz"
+fi