Add support for git commit sha (#587)

* Add support for git commit sha

copying solution from tektoncd pipeline: tektoncd/pipeline#555
Credit to @dibbles on the original PR

* Add verification of default SA creation in e2e

- Previous e2e test failed as namespace did not have default SA. Now the
test setup verifies this exists

cmd/git-init/main.go

@@ -42,15 +42,17 @@ func run(logger *zap.SugaredLogger, cmd string, args ...string) {
 	}
 }
 
-func runOrFail(logger *zap.SugaredLogger, cmd string, args ...string) {
+func runOrFail(logger *zap.SugaredLogger, cmd string, args ...string) error {
 	c := exec.Command(cmd, args...)
 	var output bytes.Buffer
 	c.Stderr = &output
 	c.Stdout = &output
 
 	if err := c.Run(); err != nil {
-		logger.Fatalf("Unexpected error running %v %v: %v\n%v", cmd, args, err, output.String())
+		logger.Errorf("Unexpected error running %v %v: %v\n%v", cmd, args, err, output.String())
+		return err
 	}
+	return nil
 }
 
 func main() {
@@ -86,8 +88,15 @@ func main() {
 	}
 
 	run(logger, "git", "remote", "add", "origin", *url)
-	runOrFail(logger, "git", "fetch", "--depth=1", "--recurse-submodules=yes", "origin", *revision)
-	runOrFail(logger, "git", "reset", "--hard", "FETCH_HEAD")
+	err = runOrFail(logger, "git", "fetch", "--depth=1", "--recurse-submodules=yes", "origin", *revision)
+	if err != nil {
+		// Fetch can fail if an old commitid was used so try git pull, performing regardless of error
+		// as no guarantee that the same error is returned by all git servers gitlab, github etc...
+		run(logger, "git", "pull", "--recurse-submodules=yes", "origin")
+		runOrFail(logger, "git", "checkout", *revision)
+	} else {
+		runOrFail(logger, "git", "reset", "--hard", "FETCH_HEAD")
+	}
 
 	logger.Infof("Successfully cloned %q @ %q in path %q", *url, *revision, dir)
 }

test/e2e/e2e.go

@@ -32,6 +32,7 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	kuberrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/apimachinery/pkg/watch"
 	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
 	"k8s.io/client-go/tools/clientcmd"
@@ -108,6 +109,20 @@ func createTestNamespace(t *testing.T) (string, *clients) {
 	return buildTestNamespace, clients
 }
 
+func verifyDefaultServiceAccountCreation(namespace string, t *testing.T, c *clients) {
+	defaultSA := "default"
+	t.Logf("Verify SA %q is created in namespace %q", defaultSA, namespace)
+	if err := wait.PollImmediate(interval, timeout, func() (bool, error) {
+		_, err := c.kubeClient.Kube.CoreV1().ServiceAccounts(namespace).Get(defaultSA, metav1.GetOptions{})
+		if err != nil && kuberrors.IsNotFound(err) {
+			return false, nil
+		}
+		return true, err
+	}); err != nil {
+		t.Fatalf("Failed to get SA %q in namespace %q for tests: %s", defaultSA, namespace, err)
+	}
+}
+
 func newClients(configPath string, clusterName string, namespace string) (*clients, error) {
 	overrides := clientcmd.ConfigOverrides{}
 	// Override the cluster name if provided.
@@ -204,7 +219,7 @@ func initialize(t *testing.T) (string, *clients) {
 	}
 
 	buildTestNamespace, clients := createTestNamespace(t)
-
+	verifyDefaultServiceAccountCreation(buildTestNamespace, t, clients)
 	// Cleanup namespace
 	test.CleanupOnInterrupt(func() { teardownNamespace(t, clients, buildTestNamespace) }, t.Logf)
 

test/git-source/1-commitid.yaml

@@ -0,0 +1,26 @@
+# Copyright 2019 The Knative Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+apiVersion: build.knative.dev/v1alpha1
+kind: Build
+metadata:
+  name: test-git-commitid
+  labels:
+    expect: succeeded
+spec:
+  source:
+    git:
+      url: https://github.com/bazelbuild/rules_docker
+      revision: 4025a58c156a4ba0fd3606df50051423043495bf
+  template:
+    name: dump-workspace-template