agent: setup grpc server with auto_encrypt certs and add -https-port (#7086)

* setup grpc server with TLS config used across consul.
* add -https-port flag

agent/agent.go

@@ -723,9 +723,9 @@ func (a *Agent) listenAndServeGRPC() error {
 	if a.config.HTTPSPort > 0 {
 		// gRPC uses the same TLS settings as the HTTPS API. If HTTPS is
 		// enabled then gRPC will require HTTPS as well.
-		a.grpcServer, err = a.xdsServer.GRPCServer(a.config.CertFile, a.config.KeyFile)
+		a.grpcServer, err = a.xdsServer.GRPCServer(a.tlsConfigurator)
 	} else {
-		a.grpcServer, err = a.xdsServer.GRPCServer("", "")
+		a.grpcServer, err = a.xdsServer.GRPCServer(nil)
 	}
 	if err != nil {
 		return err

agent/config/flags.go

@@ -79,6 +79,7 @@ func AddFlags(fs *flag.FlagSet, f *Flags) {
 	add(&f.Config.EncryptKey, "encrypt", "Provides the gossip encryption key.")
 	add(&f.Config.Ports.GRPC, "grpc-port", "Sets the gRPC API port to listen on (currently needed for Envoy xDS only).")
 	add(&f.Config.Ports.HTTP, "http-port", "Sets the HTTP API port to listen on.")
+	add(&f.Config.Ports.HTTPS, "https-port", "Sets the HTTPS API port to listen on.")
 	add(&f.Config.StartJoinAddrsLAN, "join", "Address of an agent to join at start time. Can be specified multiple times.")
 	add(&f.Config.StartJoinAddrsWAN, "join-wan", "Address of an agent to join -wan at start time. Can be specified multiple times.")
 	add(&f.Config.LogLevel, "log-level", "Log level of the agent.")

agent/config/flags_test.go

@@ -52,6 +52,14 @@ func TestParseFlags(t *testing.T) {
 			args:  []string{`-grpc-port`, `1`},
 			flags: Flags{Config: Config{Ports: Ports{GRPC: pInt(1)}}},
 		},
+		{
+			args:  []string{`-http-port`, `1`},
+			flags: Flags{Config: Config{Ports: Ports{HTTP: pInt(1)}}},
+		},
+		{
+			args:  []string{`-https-port`, `1`},
+			flags: Flags{Config: Config{Ports: Ports{HTTPS: pInt(1)}}},
+		},
 		{
 			args:  []string{`-serf-lan-port`, `1`},
 			flags: Flags{Config: Config{Ports: Ports{SerfLAN: pInt(1)}}},

agent/config/runtime.go

@@ -807,6 +807,7 @@ type RuntimeConfig struct {
 	// Setting this to a value <= 0 disables the endpoint.
 	//
 	// hcl: ports { https = int }
+	// flags: -https-port int
 	HTTPSPort int
 
 	// KeyFile is used to provide a TLS key that is used for serving TLS

agent/xds/server.go

@@ -25,6 +25,7 @@ import (
 	"github.com/hashicorp/consul/agent/connect"
 	"github.com/hashicorp/consul/agent/proxycfg"
 	"github.com/hashicorp/consul/agent/structs"
+	"github.com/hashicorp/consul/tlsutil"
 )
 
 // ADSStream is a shorter way of referring to this thing...
@@ -536,16 +537,15 @@ func (s *Server) Check(ctx context.Context, r *envoyauthz.CheckRequest) (*envoya
 
 // GRPCServer returns a server instance that can handle XDS and ext_authz
 // requests.
-func (s *Server) GRPCServer(certFile, keyFile string) (*grpc.Server, error) {
+func (s *Server) GRPCServer(tlsConfigurator *tlsutil.Configurator) (*grpc.Server, error) {
 	opts := []grpc.ServerOption{
 		grpc.MaxConcurrentStreams(2048),
 	}
-	if certFile != "" && keyFile != "" {
-		creds, err := credentials.NewServerTLSFromFile(certFile, keyFile)
-		if err != nil {
-			return nil, err
+	if tlsConfigurator != nil {
+		if tlsConfigurator.Cert() != nil {
+			creds := credentials.NewTLS(tlsConfigurator.IncomingGRPCConfig())
+			opts = append(opts, grpc.Creds(creds))
 		}
-		opts = append(opts, grpc.Creds(creds))
 	}
 	srv := grpc.NewServer(opts...)
 	envoydisco.RegisterAggregatedDiscoveryServiceServer(srv, s)

tlsutil/config.go

@@ -441,12 +441,7 @@ func (c *Configurator) commonTLSConfig(verifyIncoming bool) *tls.Config {
 	// autoEncrypt cert too so that a client can encrypt incoming
 	// connections without having a manual cert configured.
 	tlsConfig.GetCertificate = func(*tls.ClientHelloInfo) (*tls.Certificate, error) {
-		cert := c.manual.cert
-		if cert == nil {
-			cert = c.autoEncrypt.cert
-		}
-
-		return cert, nil
+		return c.Cert(), nil
 	}
 
 	// GetClientCertificate is used when acting as a client and responding
@@ -477,6 +472,17 @@ func (c *Configurator) commonTLSConfig(verifyIncoming bool) *tls.Config {
 	return tlsConfig
 }
 
+// This function acquires a read lock because it reads from the config.
+func (c *Configurator) Cert() *tls.Certificate {
+	c.RLock()
+	defer c.RUnlock()
+	cert := c.manual.cert
+	if cert == nil {
+		cert = c.autoEncrypt.cert
+	}
+	return cert
+}
+
 // This function acquires a read lock because it reads from the config.
 func (c *Configurator) VerifyIncomingRPC() bool {
 	c.RLock()
@@ -561,6 +567,22 @@ func (c *Configurator) VerifyServerHostname() bool {
 	return c.base.VerifyServerHostname || c.autoEncrypt.verifyServerHostname
 }
 
+// IncomingGRPCConfig generates a *tls.Config for incoming GRPC connections.
+func (c *Configurator) IncomingGRPCConfig() *tls.Config {
+	c.log("IncomingGRPCConfig")
+
+	// false has the effect that this config doesn't require a client cert
+	// verification. This is because there is no verify_incoming_grpc
+	// configuration option. And using verify_incoming would be backwards
+	// incompatible, because even if it was set before, it didn't have an
+	// effect on the grpc server.
+	config := c.commonTLSConfig(false)
+	config.GetConfigForClient = func(*tls.ClientHelloInfo) (*tls.Config, error) {
+		return c.IncomingGRPCConfig(), nil
+	}
+	return config
+}
+
 // IncomingRPCConfig generates a *tls.Config for incoming RPC connections.
 func (c *Configurator) IncomingRPCConfig() *tls.Config {
 	c.log("IncomingRPCConfig")

website/source/docs/agent/options.html.md

@@ -277,6 +277,10 @@ The options below are all specified on the command-line.
   to an environment which communicates the HTTP port through the environment e.g. PaaS like CloudFoundry, allowing
   you to set the port directly via a Procfile.
 
+* <a name="_https_port"></a><a href="#_https_port">`-https-port`</a> - the HTTPS API
+  port to listen on. Default -1 (https disabled). See [ports](#ports)
+  documentation for more detail.
+
 * <a name="_log_file"></a><a href="#_log_file">`-log-file`</a> - to redirect all the Consul agent log messages to a file. This can be specified with the complete path along with the name of the log. In case the path doesn't have the filename, the filename defaults to `consul-{timestamp}.log`. Can be combined with <a href="#_log_rotate_bytes"> -log-rotate-bytes</a> and <a href="#_log_rotate_duration"> -log-rotate-duration </a> for a fine-grained log rotation experience.
 
 * <a name="_log_rotate_bytes"></a><a href="#_log_rotate_bytes">`-log-rotate-bytes`</a> - to specify the number of bytes that should be written to a log before it needs to be rotated. Unless specified, there is no limit to the number of bytes that can be written to a log file.