chore(kuma-dp) extensible DP server (#1513)

Signed-off-by: Jakub Dyszkiewicz <jakub.dyszkiewicz@gmail.com>

app/kuma-cp/cmd/run.go

@@ -6,8 +6,6 @@ import (
 
 	"github.com/spf13/cobra"
 
-	"github.com/kumahq/kuma/pkg/dns"
-
 	api_server "github.com/kumahq/kuma/pkg/api-server"
 	"github.com/kumahq/kuma/pkg/clusterid"
 	"github.com/kumahq/kuma/pkg/config"
@@ -17,14 +15,18 @@ import (
 	"github.com/kumahq/kuma/pkg/core/bootstrap"
 	"github.com/kumahq/kuma/pkg/defaults"
 	"github.com/kumahq/kuma/pkg/diagnostics"
+	"github.com/kumahq/kuma/pkg/dns"
 	dp_server "github.com/kumahq/kuma/pkg/dp-server"
 	"github.com/kumahq/kuma/pkg/gc"
+	"github.com/kumahq/kuma/pkg/hds"
 	"github.com/kumahq/kuma/pkg/insights"
 	kds_global "github.com/kumahq/kuma/pkg/kds/global"
 	kds_remote "github.com/kumahq/kuma/pkg/kds/remote"
 	mads_server "github.com/kumahq/kuma/pkg/mads/server"
 	metrics "github.com/kumahq/kuma/pkg/metrics/components"
+	sds_server "github.com/kumahq/kuma/pkg/sds/server"
 	kuma_version "github.com/kumahq/kuma/pkg/version"
+	"github.com/kumahq/kuma/pkg/xds"
 )
 
 var (
@@ -94,6 +96,18 @@ func newRunCmdWithOpts(opts runCmdOpts) *cobra.Command {
 					runLog.Error(err, "unable to set up clusterID")
 					return err
 				}
+				if err := xds.Setup(rt); err != nil {
+					runLog.Error(err, "unable to set up XDS")
+					return err
+				}
+				if err := sds_server.Setup(rt); err != nil {
+					runLog.Error(err, "unable to set up SDS")
+					return err
+				}
+				if err := hds.Setup(rt); err != nil {
+					runLog.Error(err, "unable to set up HDS")
+					return err
+				}
 				if err := dp_server.SetupServer(rt); err != nil {
 					runLog.Error(err, "unable to set up DP Server")
 					return err
@@ -123,6 +137,18 @@ func newRunCmdWithOpts(opts runCmdOpts) *cobra.Command {
 					runLog.Error(err, "unable to set up GC")
 					return err
 				}
+				if err := xds.Setup(rt); err != nil {
+					runLog.Error(err, "unable to set up XDS")
+					return err
+				}
+				if err := sds_server.Setup(rt); err != nil {
+					runLog.Error(err, "unable to set up SDS")
+					return err
+				}
+				if err := hds.Setup(rt); err != nil {
+					runLog.Error(err, "unable to set up HDS")
+					return err
+				}
 				if err := dp_server.SetupServer(rt); err != nil {
 					runLog.Error(err, "unable to set up DP Server")
 					return err

app/kuma-dp/cmd/context.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/kumahq/kuma/app/kuma-dp/pkg/dataplane/envoy"
+	kumadp "github.com/kumahq/kuma/pkg/config/app/kuma-dp"
 	"github.com/kumahq/kuma/pkg/core/runtime/component"
 	leader_memory "github.com/kumahq/kuma/pkg/plugins/leader/memory"
 )
@@ -14,14 +15,17 @@ import (
 type RootContext struct {
 	ComponentManager   component.Manager
 	BootstrapGenerator envoy.BootstrapConfigFactoryFunc
+	Config             *kumadp.Config
 }
 
 func DefaultRootContext() *RootContext {
+	config := kumadp.DefaultConfig()
 	return &RootContext{
 		ComponentManager: component.NewManager(leader_memory.NewNeverLeaderElector()),
 		BootstrapGenerator: envoy.NewRemoteBootstrapGenerator(&http.Client{
 			Timeout:   10 * time.Second,
 			Transport: &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: true}},
 		}),
+		Config: &config,
 	}
 }

app/kuma-dp/cmd/run.go

@@ -6,14 +6,14 @@ import (
 	"path/filepath"
 
 	kumadp_config "github.com/kumahq/kuma/app/kuma-dp/pkg/config"
+	"github.com/kumahq/kuma/pkg/core/resources/model/rest"
 
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 
 	"github.com/kumahq/kuma/app/kuma-dp/pkg/dataplane/accesslogs"
 	"github.com/kumahq/kuma/app/kuma-dp/pkg/dataplane/envoy"
 	"github.com/kumahq/kuma/pkg/config"
-	kuma_dp "github.com/kumahq/kuma/pkg/config/app/kuma-dp"
 	config_types "github.com/kumahq/kuma/pkg/config/types"
 	"github.com/kumahq/kuma/pkg/core"
 	util_net "github.com/kumahq/kuma/pkg/util/net"
@@ -22,26 +22,36 @@ import (
 
 var runLog = dataplaneLog.WithName("run")
 
+// PersistentPreRunE in root command sets the logger and initial config
+// PreRunE loads the Kuma DP config
+// PostRunE actually runs all the components with loaded config
+// To extend Kuma DP, plug your code in RunE. Use RootContext.Config and add components to RootContext.ComponentManager
 func newRunCmd(rootCtx *RootContext) *cobra.Command {
-	cfg := kuma_dp.DefaultConfig()
+	cfg := rootCtx.Config
+	var dp *rest.Resource
+	var tmpDir string
 	cmd := &cobra.Command{
 		Use:   "run",
 		Short: "Launch Dataplane (Envoy)",
 		Long:  `Launch Dataplane (Envoy).`,
-		RunE: func(cmd *cobra.Command, _ []string) error {
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return nil
+		},
+		PreRunE: func(cmd *cobra.Command, args []string) error {
 			// only support configuration via environment variables and args
-			if err := config.Load("", &cfg); err != nil {
+			if err := config.Load("", cfg); err != nil {
 				runLog.Error(err, "unable to load configuration")
 				return err
 			}
-			if conf, err := config.ToJson(&cfg); err == nil {
+			if conf, err := config.ToJson(cfg); err == nil {
 				runLog.Info("effective configuration", "config", string(conf))
 			} else {
 				runLog.Error(err, "unable to format effective configuration", "config", cfg)
 				return err
 			}
 
-			dp, err := readDataplaneResource(cmd, &cfg)
+			var err error
+			dp, err = readDataplaneResource(cmd, cfg)
 			if err != nil {
 				runLog.Error(err, "unable to read provided dataplane")
 				return err
@@ -62,16 +72,11 @@ func newRunCmd(rootCtx *RootContext) *cobra.Command {
 			}
 
 			if cfg.DataplaneRuntime.ConfigDir == "" {
-				tmpDir, err := ioutil.TempDir("", "kuma-dp-")
+				tmpDir, err = ioutil.TempDir("", "kuma-dp-")
 				if err != nil {
 					runLog.Error(err, "unable to create a temporary directory to store generated Envoy config at")
 					return err
 				}
-				defer func() {
-					if err := os.RemoveAll(tmpDir); err != nil {
-						runLog.Error(err, "unable to remove a temporary directory with a generated Envoy config")
-					}
-				}()
 				cfg.DataplaneRuntime.ConfigDir = tmpDir
 				runLog.Info("generated Envoy configuration will be stored in a temporary directory", "dir", tmpDir)
 			}
@@ -98,11 +103,20 @@ func newRunCmd(rootCtx *RootContext) *cobra.Command {
 				}
 				cfg.ControlPlane.CaCert = string(cert)
 			}
-
+			return nil
+		},
+		PostRunE: func(cmd *cobra.Command, _ []string) error {
+			if tmpDir != "" { // clean up temp dir if it was created
+				defer func() {
+					if err := os.RemoveAll(tmpDir); err != nil {
+						runLog.Error(err, "unable to remove a temporary directory with a generated Envoy config")
+					}
+				}()
+			}
 			shouldQuit := setupQuitChannel()
 
 			dataplane, err := envoy.New(envoy.Opts{
-				Config:    cfg,
+				Config:    *cfg,
 				Generator: rootCtx.BootstrapGenerator,
 				Dataplane: dp,
 				Stdout:    cmd.OutOrStdout(),