Log in to DockerHub during staging before starting build

gcb/stage/cloudbuild.yaml

@@ -15,6 +15,7 @@ secrets:
 - kmsKeyName: projects/k8s-releng-prod/locations/global/keyRings/release/cryptoKeys/encrypt-0
   secretEnv:
     GITHUB_TOKEN: CiQAIkWjMMb2OjCHCt1hHer4ZBqqD1Mj7+dfTpvkkuzS64nrGm0SUQBLz1D+4Zwp6te6JByO/zvGpHMhW6/i3BJMRYXtNTkyBGMnZuH+J3gQfhcGL2HXjr75lHaCxF4bxPr45xen5D/Kk1+paL+XpOU3KJIADy7uGQ==
+    DOCKERHUB_TOKEN: CiQAIkWjMJDKU6Hu3pJIBf31dIl7xJQQEiccN7k1cCzGadGoT2gSTQBLz1D+uc9PMusYnFvXtJi25OqEUktDJs28d09jDyj9gcyTx9iX/JvOE3Dn2qnhrjwrUMk5bBhFjR7dHCr4mJgEVD5dXrd6yLGbDBu2
 
 steps:
 - name: gcr.io/cloud-builders/git
@@ -50,6 +51,7 @@ steps:
   - "TOOL_REF=${_TOOL_REF}"
   secretEnv:
   - GITHUB_TOKEN
+  - DOCKERHUB_TOKEN
   args:
   - "bin/krel"
   - "stage"

pkg/anago/stage.go

@@ -137,6 +137,7 @@ type stageImpl interface {
 	CommitEmpty(repo *git.Repo, msg string) error
 	Tag(repo *git.Repo, name, message string) error
 	CheckReleaseBucket(options *build.Options) error
+	DockerHubLogin() error
 	MakeCross(version string) error
 	GenerateChangelog(options *changelog.Options) error
 	StageLocalSourceTree(
@@ -216,6 +217,10 @@ func (d *defaultStageImpl) MakeCross(version string) error {
 	return build.NewMake().MakeCross(version)
 }
 
+func (d *defaultStageImpl) DockerHubLogin() error {
+	return release.DockerHubLogin()
+}
+
 func (d *defaultStageImpl) GenerateChangelog(options *changelog.Options) error {
 	return changelog.New(options).Run()
 }
@@ -459,6 +464,12 @@ func (d *DefaultStage) TagRepository() error {
 }
 
 func (d *DefaultStage) Build() error {
+	// Log in to Docker Hub to avoid getting rate limited
+	if err := d.impl.DockerHubLogin(); err != nil {
+		return errors.Wrap(err, "loging into Docker Hub")
+	}
+
+	// Call MakeCross for each of the versions we are building
 	for _, version := range d.state.versions.Ordered() {
 		if err := d.impl.MakeCross(version); err != nil {
 			return errors.Wrap(err, "build artifacts")

pkg/anago/stage_test.go

@@ -402,6 +402,12 @@ func TestBuild(t *testing.T) {
 			},
 			shouldError: true,
 		},
+		{ // DockerHubLogin fails
+			prepare: func(mock *anagofakes.FakeStageImpl) {
+				mock.DockerHubLoginReturns(err)
+			},
+			shouldError: true,
+		},
 	} {
 		opts := anago.DefaultStageOptions()
 		sut := anago.NewDefaultStage(opts)

pkg/release/release.go

@@ -130,6 +130,9 @@ const (
 	// Publishing bot issue repository
 	PubBotRepoOrg  = "k8s-release-robot"
 	PubBotRepoName = "sig-release"
+
+	DockerHubEnvKey   = "DOCKERHUB_TOKEN" // Env var containing the docker key
+	DockerHubUserName = "k8sreleng"       // Docker Hub username
 )
 
 var (
@@ -679,3 +682,23 @@ func CreatePubBotBranchIssue(branchName string) error {
 	logrus.Infof("Publishing bot issue created #%d!", issue.GetNumber())
 	return nil
 }
+
+// Calls docker login to log into docker hub using a token from the environment
+func DockerHubLogin() error {
+	// Check the environment  variable is set
+	if os.Getenv(DockerHubEnvKey) == "" {
+		return errors.New("Unable to find docker token in the environment")
+	}
+	// Pipe the token into docker login
+	cmd := command.New(
+		"docker", "login", fmt.Sprintf("--username=%s", DockerHubUserName),
+		"--password", os.Getenv(DockerHubEnvKey),
+	)
+	// Run docker login:
+	if err := cmd.RunSuccess(); err != nil {
+		errStr := strings.ReplaceAll(err.Error(), os.Getenv(DockerHubEnvKey), "**********")
+		return errors.Wrap(errors.New(errStr), "logging into Docker Hub")
+	}
+	logrus.Infof("User %s successfully logged into Docker Hub", DockerHubUserName)
+	return nil
+}