Clean up environment before each test run

Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>

Makefile

@@ -245,8 +245,12 @@ test-local:
 .PHONY: test-e2e
 test-e2e: ## Runs all Thanos e2e docker-based e2e tests from test/e2e. Required access to docker daemon.
 test-e2e: docker
+	@echo ">> cleaning docker environment."
+	@docker system prune -f --volumes
+	@echo ">> cleaning e2e test garbage."
+	@rm -rf ./test/e2e/e2e_integration_test*
 	@echo ">> running /test/e2e tests."
-	@go test -failfast -timeout 5m -v ./test/e2e/...
+	@go test -failfast -parallel 1 -timeout 5m -v ./test/e2e/...
 
 .PHONY: install-deps
 install-deps: ## Installs dependencies for integration tests. It installs supported versions of Prometheus and alertmanager to test against in integration tests.

test/e2e/rule_test.go

@@ -263,8 +263,6 @@ func TestRule_AlertmanagerHTTPClient(t *testing.T) {
 }
 
 func TestRule(t *testing.T) {
-	t.Skip("TODO(kakkoyun")
-
 	s, err := e2e.NewScenario("e2e_test_rule")
 	testutil.Ok(t, err)
 	defer s.Close()