[chore] make contrib tests more efficient (#12490)

Instead of having each test group edit modules, tidy and generate, do it
once and share the output in each subtest to save 5 minutes per branch.

Author: atoulme

.github/workflows/contrib-tests.yml

@@ -17,8 +17,26 @@ concurrency:
 permissions: read-all
 
 jobs:
+  contrib-tests-prepare:
+    runs-on: ubuntu-latest
+    if: ${{ !contains(github.event.pull_request.labels.*.name, 'Skip Contrib Tests') }}
+    steps:
+      - name: Checkout Repo
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - name: Prepare Contrib Tests
+        run: |
+          contrib_path=/tmp/opentelemetry-collector-contrib
+          git clone --depth=1 https://github.com/open-telemetry/opentelemetry-collector-contrib.git $contrib_path
+          make CONTRIB_PATH=$contrib_path prepare-contrib
+      - uses: actions/upload-artifact@v4
+        with:
+          name: contrib
+          path: /tmp/opentelemetry-collector-contrib/
+          include-hidden-files: true
+
   contrib-tests-matrix:
     runs-on: ubuntu-latest
+    needs: [contrib-tests-prepare]
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'Skip Contrib Tests') }}
     strategy:
       fail-fast: false
@@ -40,16 +58,20 @@ jobs:
     steps:
       - name: Checkout Repo
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - name: Download contrib
+        uses: actions/download-artifact@v4
+        with:
+          name: contrib
+          path: /tmp/contrib
       - name: Setup Go
         uses: actions/setup-go@f111f3307d8850f501ac008e886eec1fd1932a34 # v5.3.0
         with:
           go-version: ~1.23.6
           cache: false
-      - name: Run Contrib Tests
+      - name: Run tests
         run: |
-          contrib_path=/tmp/opentelemetry-collector-contrib
-          git clone --depth=1 https://github.com/open-telemetry/opentelemetry-collector-contrib.git $contrib_path
-          make CONTRIB_PATH=$contrib_path SKIP_RESTORE_CONTRIB=true GROUP=${{ matrix.group }} check-contrib
+          chmod +x /tmp/contrib/.tools/*
+          make CONTRIB_PATH=/tmp/contrib SKIP_RESTORE_CONTRIB=true GROUP=${{ matrix.group }} check-contrib
 
   contrib_tests:
     runs-on: ubuntu-latest

Makefile

@@ -261,17 +261,19 @@ gensemconv: $(SEMCONVGEN) $(SEMCONVKIT)
 
 ALL_MOD_PATHS := "" $(ALL_MODULES:.%=%)
 
-# Checks that the HEAD of the contrib repo checked out in CONTRIB_PATH compiles
-# against the current version of this repo.
-.PHONY: check-contrib
-check-contrib:
+.PHONY: prepare-contrib
+prepare-contrib:
 	@echo Setting contrib at $(CONTRIB_PATH) to use this core checkout
 	@$(MAKE) -j2 -C $(CONTRIB_PATH) for-all CMD="$(GOCMD) mod edit \
 		$(addprefix -replace ,$(join $(ALL_MOD_PATHS:%=go.opentelemetry.io/collector%=),$(ALL_MOD_PATHS:%=$(CURDIR)%)))"
 	@$(MAKE) -j2 -C $(CONTRIB_PATH) gotidy
 
 	@$(MAKE) generate-contrib
 
+# Checks that the HEAD of the contrib repo checked out in CONTRIB_PATH compiles
+# against the current version of this repo.
+.PHONY: check-contrib
+check-contrib:
 	@echo -e "\nRunning tests"
 	@$(MAKE) -C $(CONTRIB_PATH) gotest