feat(labels): support service and container labels, update labels and cpu/memory in-place

pkg/api/service.go

@@ -77,6 +77,9 @@ type ServiceSpec struct {
 	Configs []ConfigSpec
 	// Container defines the desired state of each container in the service.
 	Container ContainerSpec
+	// Labels are user-defined key-value metadata attached to the service. Unlike container labels, they're not
+	// applied to Docker containers. Keys must not use the reserved "uncloud." prefix.
+	Labels map[string]string
 	// Mode is the replication mode of the service. Default is ServiceModeReplicated if empty.
 	Mode string
 	Name string
@@ -157,6 +160,9 @@ func (s *ServiceSpec) Validate() error {
 	if err := s.Container.Validate(); err != nil {
 		return err
 	}
+	if err := ValidateLabels(s.Labels); err != nil {
+		return fmt.Errorf("invalid service labels: %w", err)
+	}
 
 	switch s.Mode {
 	case "", ServiceModeGlobal, ServiceModeReplicated:
@@ -243,6 +249,7 @@ func (s *ServiceSpec) Clone() ServiceSpec {
 		spec.Caddy = &caddyCopy
 	}
 	spec.Container = s.Container.Clone()
+	spec.Labels = maps.Clone(s.Labels)
 	spec.PreDeploy = s.PreDeploy.Clone()
 
 	if s.Ports != nil {
@@ -279,6 +286,10 @@ type ContainerSpec struct {
 	Image       string
 	// Run a custom init inside the container. If nil, use the daemon's configured settings.
 	Init *bool
+	// Labels are user-defined key-value metadata applied as Docker labels to each container in the service.
+	// Docker labels are immutable so changing them requires recreating the containers.
+	// Keys must not use the reserved "uncloud." prefix.
+	Labels map[string]string
 	// LogDriver overrides the default logging driver for the container. Each Docker daemon can have its own default.
 	LogDriver *LogDriver
 	// PidMode sets the PID namespace mode for the container. Currently only "" or "host" is supported.
@@ -333,6 +344,9 @@ func (s *ContainerSpec) Validate() error {
 	if _, err := reference.ParseDockerRef(s.Image); err != nil {
 		return fmt.Errorf("invalid image '%s': %w", s.Image, err)
 	}
+	if err := ValidateLabels(s.Labels); err != nil {
+		return fmt.Errorf("invalid container labels: %w", err)
+	}
 
 	for _, m := range s.VolumeMounts {
 		if err := m.Validate(); err != nil {
@@ -390,6 +404,7 @@ func (s *ContainerSpec) Clone() ContainerSpec {
 		hc.Test = slices.Clone(s.Healthcheck.Test)
 		spec.Healthcheck = &hc
 	}
+	spec.Labels = maps.Clone(s.Labels)
 	if s.LogDriver != nil {
 		logDriver := *s.LogDriver
 		if s.LogDriver.Options != nil {
@@ -428,6 +443,20 @@ func (s *ContainerSpec) Clone() ContainerSpec {
 	return spec
 }
 
+// ValidateLabels checks that label keys are non-empty and don't use the reserved Uncloud prefixes.
+func ValidateLabels(labels map[string]string) error {
+	for k := range labels {
+		if strings.TrimSpace(k) == "" {
+			return fmt.Errorf("label key must not be empty")
+		}
+		if strings.HasPrefix(k, LabelReservedPrefix) || strings.HasPrefix(k, LabelDaemonReservedPrefix) {
+			return fmt.Errorf("label '%s' cannot use the reserved prefix '%s' or '%s'",
+				k, LabelReservedPrefix, LabelDaemonReservedPrefix)
+		}
+	}
+	return nil
+}
+
 type EnvVars map[string]string
 
 // ToSlice converts the environment variables to a slice of strings in the format "key=value".