[admin] Use OTEL helper instead of tlscfg

cmd/internal/flags/admin.go

@@ -5,17 +5,16 @@
 
 import (
 	"context"
-	"crypto/tls"
 	"errors"
 	"flag"
 	"fmt"
-	"io"
 	"net"
 	"net/http"
 	"net/http/pprof"
 	"time"
 
 	"github.com/spf13/viper"
+	"go.opentelemetry.io/collector/config/confighttp"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
 
@@ -35,22 +34,22 @@
 
 // AdminServer runs an HTTP server with admin endpoints, such as healthcheck at /, /metrics, etc.
 type AdminServer struct {
-	logger               *zap.Logger
-	adminHostPort        string
-	hc                   *healthcheck.HealthCheck
-	mux                  *http.ServeMux
-	server               *http.Server
-	tlsCfg               *tls.Config
-	tlsCertWatcherCloser io.Closer
+	logger    *zap.Logger
+	hc        *healthcheck.HealthCheck
+	mux       *http.ServeMux
+	server    *http.Server
+	serverCfg *confighttp.ServerConfig
 }
 
 // NewAdminServer creates a new admin server.
 func NewAdminServer(hostPort string) *AdminServer {
 	return &AdminServer{
-		adminHostPort: hostPort,
-		logger:        zap.NewNop(),
-		hc:            healthcheck.New(),
-		mux:           http.NewServeMux(),
+		logger: zap.NewNop(),
+		hc:     healthcheck.New(),
+		mux:    http.NewServeMux(),
+		serverCfg: &confighttp.ServerConfig{
+			Endpoint: hostPort,
+		},
 	}
 }
 
@@ -67,29 +66,26 @@
 
 // AddFlags registers CLI flags.
 func (s *AdminServer) AddFlags(flagSet *flag.FlagSet) {
-	flagSet.String(adminHTTPHostPort, s.adminHostPort, fmt.Sprintf("The host:port (e.g. 127.0.0.1%s or %s) for the admin server, including health check, /metrics, etc.", s.adminHostPort, s.adminHostPort))
+	flagSet.String(adminHTTPHostPort, s.serverCfg.Endpoint, fmt.Sprintf("The host:port (e.g. 127.0.0.1%s or %s) for the admin server, including health check, /metrics, etc.", s.serverCfg.Endpoint, s.serverCfg.Endpoint))
 	tlsAdminHTTPFlagsConfig.AddFlags(flagSet)
 }
 
 // InitFromViper initializes the server with properties retrieved from Viper.
 func (s *AdminServer) initFromViper(v *viper.Viper, logger *zap.Logger) error {
 	s.setLogger(logger)
 
-	s.adminHostPort = v.GetString(adminHTTPHostPort)
-	var tlsAdminHTTP tlscfg.Options
+	s.serverCfg.Endpoint = v.GetString(adminHTTPHostPort)
 	tlsAdminHTTP, err := tlsAdminHTTPFlagsConfig.InitFromViper(v)
+	tlsAdminHTTPConfig := tlsAdminHTTP.ToOtelServerConfig()
 	if err != nil {
 		return fmt.Errorf("failed to parse admin server TLS options: %w", err)
 	}
-	if tlsAdminHTTP.Enabled {
-		tlsCfg, err := tlsAdminHTTP.Config(s.logger) // This checks if the certificates are correctly provided
+	if tlsAdminHTTPConfig != nil {
+		s.serverCfg.TLSSetting = tlsAdminHTTPConfig
+		_, err = s.serverCfg.TLSSetting.LoadTLSConfig(context.Background())
 		if err != nil {
 			return err
 		}
-		s.tlsCfg = tlsCfg
-		s.tlsCertWatcherCloser = &tlsAdminHTTP
-	} else {
-		s.tlsCertWatcherCloser = io.NopCloser(nil)
 	}
 	return nil
 }
@@ -101,7 +97,7 @@
 
 // Serve starts HTTP server.
 func (s *AdminServer) Serve() error {
-	l, err := net.Listen("tcp", s.adminHostPort)
+	l, err := net.Listen("tcp", s.serverCfg.Endpoint)
 	if err != nil {
 		s.logger.Error("Admin server failed to listen", zap.Error(err))
 		return err
@@ -127,13 +123,18 @@
 		ErrorLog:          errorLog,
 		ReadHeaderTimeout: 2 * time.Second,
 	}
-	if s.tlsCfg != nil {
-		s.server.TLSConfig = s.tlsCfg
+	if s.serverCfg.TLSSetting != nil {
+		tlsConfig, err := s.serverCfg.TLSSetting.LoadTLSConfig(context.Background())
+		if err != nil {
+			s.logger.Error("failed to load tls config", zap.Error(err))
+			s.hc.Set(healthcheck.Broken)
+		}
+		s.server.TLSConfig = tlsConfig
 	}
-	s.logger.Info("Starting admin HTTP server", zap.String("http-addr", s.adminHostPort))
+	s.logger.Info("Starting admin HTTP server", zap.String("http-addr", s.serverCfg.Endpoint))
 	go func() {
 		var err error
-		if s.tlsCfg != nil {
+		if s.serverCfg.TLSSetting != nil {
 			err = s.server.ServeTLS(l, "", "")
 		} else {
 			err = s.server.Serve(l)
@@ -160,7 +161,6 @@
 // Close stops the HTTP server
 func (s *AdminServer) Close() error {
 	return errors.Join(
-		s.tlsCertWatcherCloser.Close(),
 		s.server.Shutdown(context.Background()),
 	)
 }

cmd/internal/flags/admin_test.go

@@ -4,6 +4,7 @@
 package flags
 
 import (
+	"context"
 	"crypto/tls"
 	"fmt"
 	"net"
@@ -133,9 +134,8 @@ func TestAdminServerTLS(t *testing.T) {
 			adminServer.Serve()
 			defer adminServer.Close()
 
-			clientTLSCfg, err0 := test.clientTLS.Config(zap.NewNop())
+			clientTLSCfg, err0 := test.clientTLS.ToOtelClientConfig().LoadTLSConfig(context.Background())
 			require.NoError(t, err0)
-			defer test.clientTLS.Close()
 			dialer := &net.Dialer{Timeout: 2 * time.Second}
 			conn, clientError := tls.DialWithDialer(dialer, "tcp", fmt.Sprintf("localhost:%d", ports.CollectorAdminHTTP), clientTLSCfg)
 			require.NoError(t, clientError)