feat(parser) add flag to log diff on failure

cli/ingress-controller/flags.go

@@ -28,6 +28,7 @@ import (
 	apiv1 "k8s.io/api/core/v1"
 
 	"github.com/kong/kubernetes-ingress-controller/pkg/annotations"
+	"github.com/kong/kubernetes-ingress-controller/pkg/util"
 )
 
 const (
@@ -80,6 +81,9 @@ type cliConfig struct {
 	LogLevel  string
 	LogFormat string
 
+	// Diagnostics
+	DumpConfig util.ConfigDumpMode
+
 	// k8s connection details
 	APIServerHost      string
 	KubeConfigFilePath string
@@ -199,6 +203,11 @@ trace, debug, info, warn, error, fatal and panic.`)
 		`Format of logs of the controller. Allowed values are 
 text and json.`)
 
+	// Diagnostics
+	flags.String("dump-config", "",
+		`Dump generated configuration to a temporary directory when set to "enabled".
+When set to "sensitive", dumps will include certificate+key pairs and credentials.`)
+
 	// k8s connection details
 	flags.String("apiserver-host", "",
 		`The address of the Kubernetes Apiserver to connect to in the format of 
@@ -311,6 +320,9 @@ func parseFlags() (cliConfig, error) {
 	config.LogLevel = viper.GetString("log-level")
 	config.LogFormat = viper.GetString("log-format")
 
+	// Diagnostics
+	config.DumpConfig = util.ParseConfigDumpMode(viper.GetString("dump-config"))
+
 	// k8s connection details
 	config.APIServerHost = viper.GetString("apiserver-host")
 	config.KubeConfigFilePath = viper.GetString("kubeconfig")

cli/ingress-controller/main.go

@@ -103,6 +103,8 @@ func controllerConfigFromCLIConfig(cliConfig cliConfig) controller.Configuration
 		UpdateStatus:           cliConfig.UpdateStatus,
 		UpdateStatusOnShutdown: cliConfig.UpdateStatusOnShutdown,
 		ElectionID:             cliConfig.ElectionID,
+
+		DumpConfig: cliConfig.DumpConfig,
 	}
 }
 
@@ -453,8 +455,17 @@ func main() {
 
 	store := store.New(cacheStores, cliConfig.IngressClass, cliConfig.ProcessClasslessIngressV1Beta1,
 		cliConfig.ProcessClasslessIngressV1, cliConfig.ProcessClasslessKongConsumer, log.WithField("component", "store"))
+
+	var dumpDir string
+	if cliConfig.DumpConfig > 0 {
+		var err error
+		dumpDir, err = ioutil.TempDir("", "controller")
+		if err != nil {
+			log.Fatalf("failed to create a dump directory: %v", err)
+		}
+	}
 	kong, err := controller.NewKongController(ctx, &controllerConfig, updateChannel,
-		store)
+		store, dumpDir)
 	if err != nil {
 		log.Fatalf("failed to create a controller: %v", err)
 	}

cli/ingress-controller/main_test.go

@@ -82,6 +82,7 @@ func TestHandleSigterm(t *testing.T) {
 		channels.NewRingChannel(1024),
 		store.New(store.CacheStores{}, conf.IngressClass, conf.ProcessClasslessIngressV1Beta1,
 			conf.ProcessClasslessIngressV1, conf.ProcessClasslessKongConsumer, logrus.New()),
+		"", // dump dir, not used in this test
 	)
 
 	exitCh := make(chan int, 1)

internal/ingress/controller/controller.go

@@ -91,6 +91,8 @@ type Configuration struct {
 	EnableKnativeIngressSupport bool
 
 	Logger logrus.FieldLogger
+
+	DumpConfig util.ConfigDumpMode
 }
 
 // sync collects all the pieces required to assemble the configuration file and
@@ -129,7 +131,8 @@ func (n *KongController) syncIngress(interface{}) error {
 func NewKongController(ctx context.Context,
 	config *Configuration,
 	updateCh *channels.RingChannel,
-	store store.Storer) (*KongController, error) {
+	store store.Storer,
+	dumpDir string) (*KongController, error) {
 	eventBroadcaster := record.NewBroadcaster()
 	eventBroadcaster.StartRecordingToSink(&v1core.EventSinkImpl{
 		Interface: config.KubeClient.CoreV1().Events(config.Namespace),
@@ -152,6 +155,8 @@ func NewKongController(ctx context.Context,
 	n.syncQueue = task.NewTaskQueue(n.syncIngress,
 		config.Logger.WithField("component", "sync-queue"))
 
+	n.dumpDir = dumpDir
+
 	electionID := config.ElectionID + "-" + config.IngressClass
 
 	electionConfig := election.Config{
@@ -231,6 +236,8 @@ type KongController struct {
 	PluginSchemaStore PluginSchemaStore
 
 	Logger logrus.FieldLogger
+
+	dumpDir string
 }
 
 // Start starts a new master process running in foreground, blocking until the next call to

internal/ingress/controller/kong.go

@@ -22,7 +22,9 @@ import (
 	"crypto/sha256"
 	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"net/http"
+	"path/filepath"
 	"reflect"
 	"sort"
 	"strings"
@@ -72,8 +74,28 @@ func (n *KongController) OnUpdate(ctx context.Context, state *kongstate.KongStat
 	} else {
 		err = n.onUpdateDBMode(targetContent)
 	}
+	var target []byte
+	if n.cfg.DumpConfig == util.ConfigDumpModeSensitive {
+		target, _ = json.Marshal(targetContent)
+	} else if n.cfg.DumpConfig == util.ConfigDumpModeEnabled {
+		sanitizedState := state.SanitizedCopy()
+		target, _ = json.Marshal(n.toDeckContent(ctx, sanitizedState))
+	}
 	if err != nil {
+		if len(target) > 0 {
+			dumpErr := ioutil.WriteFile(filepath.Join(n.dumpDir, "target.json"), target, 0600)
+			if dumpErr != nil {
+				n.Logger.Warnf("failed to dump configuration: %s", dumpErr)
+			}
+		}
 		return err
+	} else {
+		if len(target) > 0 {
+			dumpErr := ioutil.WriteFile(filepath.Join(n.dumpDir, "last_good.json"), target, 0600)
+			if dumpErr != nil {
+				n.Logger.Warnf("failed to dump configuration: %s", dumpErr)
+			}
+		}
 	}
 	n.runningConfigHash = shaSum
 	n.Logger.Info("successfully synced configuration to kong")

pkg/util/types.go

@@ -29,3 +29,22 @@ type RawSSLCert struct {
 	Cert []byte
 	Key  []byte
 }
+
+type ConfigDumpMode int
+
+const (
+	ConfigDumpModeOff       ConfigDumpMode = iota
+	ConfigDumpModeEnabled   ConfigDumpMode = iota
+	ConfigDumpModeSensitive ConfigDumpMode = iota
+)
+
+func ParseConfigDumpMode(in string) ConfigDumpMode {
+	switch in {
+	case "enabled":
+		return ConfigDumpModeEnabled
+	case "sensitive":
+		return ConfigDumpModeSensitive
+	default:
+		return ConfigDumpModeOff
+	}
+}