Merge pull request #5416 from hashicorp/b-docker-email

Fix regression with requiring docker auth email

drivers/docker/driver_test.go

@@ -1664,6 +1664,60 @@ func TestDockerDriver_AuthConfiguration(t *testing.T) {
 	}
 }
 
+func TestDockerDriver_AuthFromTaskConfig(t *testing.T) {
+	if !tu.IsCI() {
+		t.Parallel()
+	}
+
+	cases := []struct {
+		Auth       DockerAuth
+		AuthConfig *docker.AuthConfiguration
+		Desc       string
+	}{
+		{
+			Auth:       DockerAuth{},
+			AuthConfig: nil,
+			Desc:       "Empty Config",
+		},
+		{
+			Auth: DockerAuth{
+				Username:   "foo",
+				Password:   "bar",
+				Email:      "foo@bar.com",
+				ServerAddr: "www.foobar.com",
+			},
+			AuthConfig: &docker.AuthConfiguration{
+				Username:      "foo",
+				Password:      "bar",
+				Email:         "foo@bar.com",
+				ServerAddress: "www.foobar.com",
+			},
+			Desc: "All fields set",
+		},
+		{
+			Auth: DockerAuth{
+				Username:   "foo",
+				Password:   "bar",
+				ServerAddr: "www.foobar.com",
+			},
+			AuthConfig: &docker.AuthConfiguration{
+				Username:      "foo",
+				Password:      "bar",
+				ServerAddress: "www.foobar.com",
+			},
+			Desc: "Email not set",
+		},
+	}
+
+	for _, c := range cases {
+		t.Run(c.Desc, func(t *testing.T) {
+			act, err := authFromTaskConfig(&TaskConfig{Auth: c.Auth})("test")
+			require.NoError(t, err)
+			require.Exactly(t, c.AuthConfig, act)
+		})
+	}
+}
+
 func TestDockerDriver_OOMKilled(t *testing.T) {
 	if !tu.IsCI() {
 		t.Parallel()

drivers/docker/utils.go

@@ -82,7 +82,8 @@ func firstValidAuth(repo string, backends []authBackend) (*docker.AuthConfigurat
 // authFromTaskConfig generates an authBackend for any auth given in the task-configuration
 func authFromTaskConfig(driverConfig *TaskConfig) authBackend {
 	return func(string) (*docker.AuthConfiguration, error) {
-		if len(driverConfig.Auth.Email) == 0 {
+		// If all auth fields are empty, return
+		if len(driverConfig.Auth.Username) == 0 && len(driverConfig.Auth.Password) == 0 && len(driverConfig.Auth.Email) == 0 && len(driverConfig.Auth.ServerAddr) == 0 {
 			return nil, nil
 		}
 		return &docker.AuthConfiguration{