proxy supports configuring annotations, which will be displayed in the frps dashboard (#4000)

pkg/config/v1/proxy.go

@@ -105,9 +105,10 @@ type DomainConfig struct {
 }
 
 type ProxyBaseConfig struct {
-	Name      string         `json:"name"`
-	Type      string         `json:"type"`
-	Transport ProxyTransport `json:"transport,omitempty"`
+	Name        string            `json:"name"`
+	Type        string            `json:"type"`
+	Annotations map[string]string `json:"annotations,omitempty"`
+	Transport   ProxyTransport    `json:"transport,omitempty"`
 	// metadata info for each proxy
 	Metadatas    map[string]string  `json:"metadatas,omitempty"`
 	LoadBalancer LoadBalancerConfig `json:"loadBalancer,omitempty"`
@@ -138,6 +139,7 @@ func (c *ProxyBaseConfig) MarshalToMsg(m *msg.NewProxy) {
 	m.Group = c.LoadBalancer.Group
 	m.GroupKey = c.LoadBalancer.GroupKey
 	m.Metas = c.Metadatas
+	m.Annotations = c.Annotations
 }
 
 func (c *ProxyBaseConfig) UnmarshalFromMsg(m *msg.NewProxy) {
@@ -154,6 +156,7 @@ func (c *ProxyBaseConfig) UnmarshalFromMsg(m *msg.NewProxy) {
 	c.LoadBalancer.Group = m.Group
 	c.LoadBalancer.GroupKey = m.GroupKey
 	c.Metadatas = m.Metas
+	c.Annotations = m.Annotations
 }
 
 type TypedProxyConfig struct {

pkg/config/v1/validation/proxy.go

@@ -20,6 +20,7 @@ import (
 	"strings"
 
 	"github.com/samber/lo"
+	"k8s.io/apimachinery/pkg/util/validation"
 
 	v1 "github.com/fatedier/frp/pkg/config/v1"
 )
@@ -29,10 +30,12 @@ func validateProxyBaseConfigForClient(c *v1.ProxyBaseConfig) error {
 		return errors.New("name should not be empty")
 	}
 
+	if err := ValidateAnnotations(c.Annotations); err != nil {
+		return err
+	}
 	if !lo.Contains([]string{"", "v1", "v2"}, c.Transport.ProxyProtocolVersion) {
 		return fmt.Errorf("not support proxy protocol version: %s", c.Transport.ProxyProtocolVersion)
 	}
-
 	if !lo.Contains([]string{"client", "server"}, c.Transport.BandwidthLimitMode) {
 		return fmt.Errorf("bandwidth limit mode should be client or server")
 	}
@@ -61,7 +64,10 @@ func validateProxyBaseConfigForClient(c *v1.ProxyBaseConfig) error {
 	return nil
 }
 
-func validateProxyBaseConfigForServer(c *v1.ProxyBaseConfig, s *v1.ServerConfig) error {
+func validateProxyBaseConfigForServer(c *v1.ProxyBaseConfig) error {
+	if err := ValidateAnnotations(c.Annotations); err != nil {
+		return err
+	}
 	return nil
 }
 
@@ -161,7 +167,7 @@ func validateSUDPProxyConfigForClient(c *v1.SUDPProxyConfig) error {
 
 func ValidateProxyConfigurerForServer(c v1.ProxyConfigurer, s *v1.ServerConfig) error {
 	base := c.GetBaseConfig()
-	if err := validateProxyBaseConfigForServer(base, s); err != nil {
+	if err := validateProxyBaseConfigForServer(base); err != nil {
 		return err
 	}
 
@@ -231,3 +237,34 @@ func validateXTCPProxyConfigForServer(c *v1.XTCPProxyConfig, s *v1.ServerConfig)
 func validateSUDPProxyConfigForServer(c *v1.SUDPProxyConfig, s *v1.ServerConfig) error {
 	return nil
 }
+
+// ValidateAnnotations validates that a set of annotations are correctly defined.
+func ValidateAnnotations(annotations map[string]string) error {
+	if len(annotations) == 0 {
+		return nil
+	}
+
+	var errs error
+	for k := range annotations {
+		for _, msg := range validation.IsQualifiedName(strings.ToLower(k)) {
+			errs = AppendError(errs, fmt.Errorf("annotation key %s is invalid: %s", k, msg))
+		}
+	}
+	if err := ValidateAnnotationsSize(annotations); err != nil {
+		errs = AppendError(errs, err)
+	}
+	return errs
+}
+
+const TotalAnnotationSizeLimitB int = 256 * (1 << 10) // 256 kB
+
+func ValidateAnnotationsSize(annotations map[string]string) error {
+	var totalSize int64
+	for k, v := range annotations {
+		totalSize += (int64)(len(k)) + (int64)(len(v))
+	}
+	if totalSize > (int64)(TotalAnnotationSizeLimitB) {
+		return fmt.Errorf("annotations size %d is larger than limit %d", totalSize, TotalAnnotationSizeLimitB)
+	}
+	return nil
+}