Improve integration test speed

.github/workflows/integration.yml

@@ -6,6 +6,9 @@ on:
   push:
     branches: [main]
 
+permissions:
+  contents: read
+
 jobs:
   detect-integration-changes:
     runs-on: ubuntu-latest
@@ -38,20 +41,44 @@ jobs:
     env:
       # Compose can be slow on runners (Kafka + topic init + server build)
       INTEGRATION_READY_TIMEOUT: 120s
+      # BuildKit + compose build: better layer reuse; GHA cache requires buildx (see below).
+      DOCKER_BUILDKIT: 1
+      COMPOSE_DOCKER_CLI_BUILD: 1
 
     steps:
       - name: Checkout repo
         uses: actions/checkout@v4
 
+      - name: Cache Docker images
+        uses: ScribeMD/docker-cache@0.5.0
+        with:
+          key: docker-cache-${{ runner.os }}-${{ hashFiles('docker-compose.yml', 'docker-compose.dev.yml', 'testing/integration/docker-compose.integration.yml', 'testing/integration/docker-compose.ci-cache.yml') }}
+
+      # Enables type=gha BuildKit cache used in testing/integration/docker-compose.ci-cache.yml
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
       - name: Set up Go
         uses: actions/setup-go@v5
         with:
           go-version-file: go.mod
           cache: true
 
-      # make integration = docker compose up + go test -tags=integration (see testing/Makefile)
+      - name: Pull and run services
+        run: |
+          docker compose \
+            --project-directory "${{ github.workspace }}" \
+            -f docker-compose.dev.yml \
+            -f testing/integration/docker-compose.integration.yml \
+            -f testing/integration/docker-compose.ci-cache.yml \
+            up -d --build
+
+      # make integration = docker compose up + go test -tags=integration (see testing/Makefile).
+      # On GitHub Actions, Makefile adds docker-compose.ci-cache.yml for BuildKit GHA layer cache.
       - name: Run integration tests
-        run: make integration
+        run: |
+          cd testing/integration
+          go test -tags=integration -count=1 -parallel 8 -v ./...
 
       - name: Tear down Compose
         if: always()

testing/Makefile

@@ -5,18 +5,26 @@ _TESTING_ABS := $(abspath $(dir $(lastword $(MAKEFILE_LIST))))
 REPO_ROOT     := $(abspath $(_TESTING_ABS)/..)
 COMPOSE_BASE     := $(REPO_ROOT)/docker-compose.dev.yml
 COMPOSE_INT      := $(REPO_ROOT)/testing/integration/docker-compose.integration.yml
+COMPOSE_CI_CACHE := $(REPO_ROOT)/testing/integration/docker-compose.ci-cache.yml
 COMPOSE_LOAD     := $(REPO_ROOT)/testing/load/docker-compose.load.yml
 INTEGRATION_DIR  := $(REPO_ROOT)/testing/integration
 LOAD_DIR         := $(REPO_ROOT)/testing/load
 
+# GitHub Actions sets GITHUB_ACTIONS=true — use BuildKit GHA cache (type=gha) for image builds.
+ifeq ($(GITHUB_ACTIONS),true)
+COMPOSE_EXTRA := -f $(COMPOSE_CI_CACHE)
+else
+COMPOSE_EXTRA :=
+endif
+
 # Default to running all integration tests if no filter is provided
 TEST ?= all
 
 .PHONY: integration load teardown teardown-integration teardown-load _up_integration _up_load
 
 # Tear down Compose stacks (absolute -f paths; works from any cwd).
 teardown-integration:
-	docker compose --project-directory "$(REPO_ROOT)" -f $(COMPOSE_BASE) -f $(COMPOSE_INT) down
+	docker compose --project-directory "$(REPO_ROOT)" -f $(COMPOSE_BASE) -f $(COMPOSE_INT) $(COMPOSE_EXTRA) down
 
 teardown-load:
 	docker compose --project-directory "$(REPO_ROOT)" -f $(COMPOSE_BASE) -f $(COMPOSE_LOAD) down
@@ -30,11 +38,11 @@ teardown: teardown-integration teardown-load
 #   make integration TEST=create      (event creation flow only)
 integration: _up_integration
 ifeq ($(TEST),register)
-	cd $(INTEGRATION_DIR) && go test -tags=integration -v -run TestRegistration ./...
+	cd $(INTEGRATION_DIR) && go test -tags=integration -count=1 -parallel 8 -v -run TestRegistration ./...
 else ifeq ($(TEST),create)
-	cd $(INTEGRATION_DIR) && go test -tags=integration -v -run TestEventCreation ./...
+	cd $(INTEGRATION_DIR) && go test -tags=integration -count=1 -parallel 8 -v -run TestEventCreation ./...
 else
-	cd $(INTEGRATION_DIR) && go test -tags=integration -v ./...
+	cd $(INTEGRATION_DIR) && go test -tags=integration -count=1 -parallel 8 -v ./...
 endif
 
 # Flood the registration endpoint with concurrent requests via k6
@@ -49,6 +57,7 @@ _up_integration:
 		--project-directory "$(REPO_ROOT)" \
 		-f $(COMPOSE_BASE) \
 		-f $(COMPOSE_INT) \
+		$(COMPOSE_EXTRA) \
 		up -d --build
 
 # Spin up the stack with mock Clark for load tests (leaves containers running)

testing/integration/creation_test.go

@@ -12,6 +12,7 @@ import (
 // TestEventCreationFlow_CreateAndRetrieve creates an event and verifies it can be
 // fetched back with matching fields.
 func TestEventCreationFlow_CreateAndRetrieve(t *testing.T) {
+	t.Parallel()
 	body := defaultEvent("Create And Retrieve Test", 50)
 	eventID := createEvent(t, "admin-create-retrieve", body)
 
@@ -42,6 +43,7 @@ func TestEventCreationFlow_CreateAndRetrieve(t *testing.T) {
 // TestEventCreationFlow_Update creates an event, patches the name and location,
 // then verifies the updated values are returned.
 func TestEventCreationFlow_Update(t *testing.T) {
+	t.Parallel()
 	eventID := createEvent(t, "admin-update", defaultEvent("Update Test Original", 50))
 
 	patch, _ := json.Marshal(map[string]interface{}{
@@ -83,6 +85,7 @@ func TestEventCreationFlow_Update(t *testing.T) {
 // TestEventCreationFlow_Delete creates an event, deletes it, and verifies a
 // subsequent GET returns 404. Only draft or closed events may be deleted (see DeleteEventByID).
 func TestEventCreationFlow_Delete(t *testing.T) {
+	t.Parallel()
 	body := defaultEvent("Delete Test", 50)
 	body["status"] = "draft"
 	eventID := createEvent(t, "admin-delete", body)

testing/integration/docker-compose.ci-cache.yml

@@ -0,0 +1,16 @@
+# CI-only: enable BuildKit GitHub Actions cache for custom images (see .github/workflows/integration.yml).
+# Loaded when CI=true (GitHub Actions sets this automatically). Safe to omit locally.
+services:
+  server:
+    build:
+      cache_from:
+        - type=gha,scope=server
+      cache_to:
+        - type=gha,mode=max,scope=server
+
+  mock-clark:
+    build:
+      cache_from:
+        - type=gha,scope=mock-clark
+      cache_to:
+        - type=gha,mode=max,scope=mock-clark

testing/integration/registration_test.go

@@ -15,6 +15,7 @@ func isRegistrationSubmitted(status int) bool {
 // TestRegistrationFlow_BasicRegistration creates an event, registers a user,
 // and verifies the registration is accepted by the Kafka consumer.
 func TestRegistrationFlow_BasicRegistration(t *testing.T) {
+	t.Parallel()
 	eventID := createEvent(t, "admin-basic-reg", defaultEvent("Basic Registration Test", 100))
 
 	status, requestID := registerForEvent(eventID, "user-basic-reg", "Alice Smith", "alice@example.com")
@@ -37,6 +38,7 @@ func TestRegistrationFlow_BasicRegistration(t *testing.T) {
 // TestRegistrationFlow_DuplicateRegistration verifies that registering the same
 // user for the same event twice is rejected with 409.
 func TestRegistrationFlow_DuplicateRegistration(t *testing.T) {
+	t.Parallel()
 	eventID := createEvent(t, "admin-dup-reg", defaultEvent("Duplicate Registration Test", 100))
 
 	// first registration
@@ -60,6 +62,7 @@ func TestRegistrationFlow_DuplicateRegistration(t *testing.T) {
 // TestRegistrationFlow_CapacityFull creates an event with capacity 1, fills it,
 // then verifies a second user's registration is rejected as capacity_full.
 func TestRegistrationFlow_CapacityFull(t *testing.T) {
+	t.Parallel()
 	eventID := createEvent(t, "admin-cap-full", defaultEvent("Capacity Full Test", 1))
 
 	// register first user — should be accepted