Major refactoring & implement standalone mode

cmd/remote-work-processor/cmd_options.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"flag"
+	"io"
+	"log"
+	"os"
+)
+
+type Options struct {
+	DisplayVersion bool
+	StandaloneMode bool
+	InstanceId     string
+	MaxConnRetries uint
+}
+
+const (
+	standaloneModeOpt = "standalone-mode"
+	instanceIdOpt     = "instance-id"
+	connRetriesOpt    = "conn-retries"
+	versionOpt        = "version"
+)
+
+func (opts *Options) BindFlags(fs *flag.FlagSet) {
+	hostname := getHashedHostname()
+
+	fs.BoolVar(&opts.StandaloneMode, standaloneModeOpt, false,
+		"Whether to run the Remote Work Processor in Standalone mode")
+	fs.StringVar(&opts.InstanceId, instanceIdOpt, hostname,
+		"Instance Identifier for the Remote Work Processor (only applicable for Standalone mode)")
+	fs.UintVar(&opts.MaxConnRetries, connRetriesOpt, 3, "Number of retries for gRPC connection to AutoPi server")
+	fs.BoolVar(&opts.DisplayVersion, versionOpt, false, "Display binary version and exit")
+}
+
+func getHashedHostname() string {
+	hostname, err := os.Hostname()
+	if err != nil {
+		log.Printf("could not get hostname: %v\n", err)
+	} else {
+		hasher := sha256.New()
+		io.WriteString(hasher, hostname)
+		hostname = hex.EncodeToString(hasher.Sum(nil))
+	}
+	return hostname
+}

cmd/remote-work-processor/main.go

@@ -17,80 +17,149 @@
 package main
 
 import (
-	// "flag"
-	// "os"
-
-	// Import all Kubernetes client auth plugins (e.g. Azure, GCP, OIDC, etc.)
-	// to ensure that exec-entrypoint and run can make use of them.
-
+	"context"
+	"flag"
+	"fmt"
+	"github.com/SAP/remote-work-processor/internal/grpc"
+	"github.com/SAP/remote-work-processor/internal/grpc/processors"
+	"github.com/SAP/remote-work-processor/internal/kubernetes/controller"
+	meta "github.com/SAP/remote-work-processor/internal/kubernetes/metadata"
+	"k8s.io/apimachinery/pkg/runtime"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	"log"
 	"os"
-
+	"os/signal"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/log/zap"
+	"syscall"
+	// Import all Kubernetes client auth plugins (e.g. Azure, GCP, OIDC, etc.)
+	// to ensure that exec-entrypoint and run can make use of them.
 	_ "k8s.io/client-go/plugin/pkg/client/auth"
 	"k8s.io/client-go/rest"
-	"k8s.io/client-go/tools/clientcmd"
-
-	"k8s.io/apimachinery/pkg/runtime"
-	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
-	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
-
-	// "sigs.k8s.io/controller-runtime/pkg/healthz"
-	// "sigs.k8s.io/controller-runtime/pkg/log/zap"
-	// "github.com/SAP/remote-work-processor/kubernetes/controllers"
-	"github.com/SAP/remote-work-processor/internal/grpc"
-	"github.com/SAP/remote-work-processor/internal/grpc/processors"
-	"github.com/SAP/remote-work-processor/internal/kubernetes/controller"
-	"github.com/SAP/remote-work-processor/internal/kubernetes/metadata"
 	//+kubebuilder:scaffold:imports
 )
 
 var (
-	scheme = runtime.NewScheme()
+	// Version of the Remote Work Processor.
+	// Injected at linking time via ldflags.
+	Version string
+	// BuildDate of the Remote Work Processor.
+	// Injected at linking time via ldflags.
+	BuildDate string
 )
 
-func init() {
-	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
-	//+kubebuilder:scaffold:scheme
-}
-
 func main() {
-	metadata.InitRemoteWorkProcessorMetadata()
-	config := getKubeConfig()
+	opts := setupFlagsAndLogger()
 
-	e := controller.CreateManagerEngine(scheme, config)
-	processors.InitProcessorFactory(e)
-	grpc.InitRemoteWorkProcessorGrpcClient()
+	if opts.DisplayVersion {
+		fmt.Printf("rwp-%s Built: %s\n", Version, BuildDate)
+		return
+	}
 
-	opc := grpc.Client.Receive()
+	rootCtx, _ := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
 
-	for {
-		op := <-opc
-		p, err := processors.Factory.CreateProcessor(op)
-		if err != nil {
-			log.Fatalf("Error occurred while creating operation processor: %v\n", err)
-		}
+	rwpMetadata := meta.LoadMetadata(opts.InstanceId, Version)
+	grpcClient := grpc.NewClient(rwpMetadata, opts.StandaloneMode)
+	var drainChan chan struct{}
 
-		res := <-p.Process()
-		if res.Err != nil {
-			log.Fatalf("Error occurred while processing operation: %v\n", err)
-		}
+	var factory processors.ProcessorFactory
+
+	if opts.StandaloneMode {
+		factory = processors.NewStandaloneProcessorFactory()
+	} else {
+		config := getKubeConfig()
+		scheme := runtime.NewScheme()
+		utilruntime.Must(clientgoscheme.AddToScheme(scheme))
+		//+kubebuilder:scaffold:scheme
 
-		if res.Result != nil {
-			grpc.Client.Send(res.Result)
+		drainChan = make(chan struct{}, 1)
+		engine := controller.CreateManagerEngine(scheme, config, grpcClient)
+		factory = processors.NewKubernetesProcessorFactory(engine, drainChan)
+	}
+
+	connAttemptChan := make(chan struct{}, 1)
+	connAttemptChan <- struct{}{}
+	var connAttempts uint = 0
+
+Loop:
+	for connAttempts < opts.MaxConnRetries {
+		select {
+		case <-rootCtx.Done():
+			break Loop
+		case <-connAttemptChan:
+			err := grpcClient.InitSession(rootCtx, rwpMetadata.SessionID())
+			if err != nil {
+				signalRetry(&connAttempts, connAttemptChan, err)
+			}
+		default:
+			operation, err := grpcClient.ReceiveMsg()
+			if err != nil {
+				signalRetry(&connAttempts, connAttemptChan, err)
+				continue
+			}
+			if operation == nil {
+				// this flow is only when the backend closes the gRPC connection
+				connAttemptChan <- struct{}{}
+				// do not increment the retries, as this isn't a failure
+				continue
+			}
+
+			processor, err := factory.CreateProcessor(operation)
+			if err != nil {
+				log.Printf("error creating operation processor: %v\n", err)
+				continue
+			}
+
+			msg, err := processor.Process(rootCtx)
+			//TODO: not every error needs session reestablishment; make a custom error struct and only
+			// recreation the session based on error type
+			if err != nil {
+				//TODO: check how the backed handles the case when the client doesn't send a "confirm" message
+				// ensure there are retries in case there isn't a confirmation
+				signalRetry(&connAttempts, connAttemptChan, fmt.Errorf("error processing operation: %v", err))
+				continue
+			}
+			if msg == nil {
+				continue
+			}
+
+			if err = grpcClient.Send(msg); err != nil {
+				signalRetry(&connAttempts, connAttemptChan, err)
+			}
 		}
 	}
+
+	if !opts.StandaloneMode {
+		// wait for context cancellation to be propagated to the k8s manager
+		<-drainChan
+	}
 }
 
-func getKubeConfig() *rest.Config {
-	rules := clientcmd.NewDefaultClientConfigLoadingRules()
-	overrides := &clientcmd.ConfigOverrides{}
+func setupFlagsAndLogger() *Options {
+	opts := &Options{}
+	opts.BindFlags(flag.CommandLine)
 
-	kubeConfig := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(rules, overrides)
+	zapOpts := zap.Options{}
+	zapOpts.BindFlags(flag.CommandLine)
 
-	config, err := kubeConfig.ClientConfig()
+	flag.Parse()
+	ctrl.SetLogger(zap.New(zap.UseFlagOptions(&zapOpts)))
+	return opts
+}
+
+func getKubeConfig() *rest.Config {
+	config, err := rest.InClusterConfig()
 	if err != nil {
-		os.Exit(1)
+		log.Fatalln("Could not create kubeconfig:", err)
 	}
-
 	return config
 }
+
+func signalRetry(attempts *uint, retryChan chan<- struct{}, err error) {
+	if err != nil {
+		log.Println(err)
+	}
+	retryChan <- struct{}{}
+	*attempts++
+}

go.mod

@@ -4,7 +4,6 @@ go 1.20
 
 require (
 	github.com/itchyny/gojq v0.12.12
-	github.com/pkg/errors v0.9.1
 	google.golang.org/grpc v1.55.0
 	google.golang.org/protobuf v1.30.0
 	k8s.io/apimachinery v0.26.1
@@ -20,6 +19,7 @@ require (
 	github.com/evanphx/json-patch/v5 v5.6.0 // indirect
 	github.com/fsnotify/fsnotify v1.6.0 // indirect
 	github.com/go-logr/logr v1.2.3 // indirect
+	github.com/go-logr/zapr v1.2.3 // indirect
 	github.com/go-openapi/jsonpointer v0.19.5 // indirect
 	github.com/go-openapi/jsonreference v0.20.0 // indirect
 	github.com/go-openapi/swag v0.19.14 // indirect
@@ -39,11 +39,15 @@ require (
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
 	github.com/prometheus/client_golang v1.14.0 // indirect
 	github.com/prometheus/client_model v0.3.0 // indirect
 	github.com/prometheus/common v0.37.0 // indirect
 	github.com/prometheus/procfs v0.8.0 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
+	go.uber.org/atomic v1.7.0 // indirect
+	go.uber.org/multierr v1.6.0 // indirect
+	go.uber.org/zap v1.24.0 // indirect
 	golang.org/x/net v0.8.0 // indirect
 	golang.org/x/oauth2 v0.6.0 // indirect
 	golang.org/x/sys v0.6.0 // indirect

go.sum

@@ -38,6 +38,8 @@ github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751/go.mod h1:LOuy
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/alecthomas/units v0.0.0-20190717042225-c3de453c63f4/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d/go.mod h1:rBZYJk541a8SKzHPHnH3zbiI+7dagKZ0cgpgrD7Fyho=
+github.com/benbjohnson/clock v1.1.0 h1:Q92kusRqC1XV2MjkWETPvjJVqKetz1OzxZB7mHJLju8=
+github.com/benbjohnson/clock v1.1.0/go.mod h1:J11/hYXuz8f4ySSvYwY0FKfm+ezbsZBKZxNJlLklBHA=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
 github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
@@ -81,9 +83,11 @@ github.com/go-logfmt/logfmt v0.4.0/go.mod h1:3RMwSq7FuexP4Kalkev3ejPJsZTpXXBr9+V
 github.com/go-logfmt/logfmt v0.5.0/go.mod h1:wCYkCAKZfumFQihp8CzCvQ3paCTfi41vtzG1KdI/P7A=
 github.com/go-logfmt/logfmt v0.5.1/go.mod h1:WYhtIu8zTZfxdn5+rREduYbwxfcBr/Vr6KEVveWlfTs=
 github.com/go-logr/logr v1.2.0/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
 github.com/go-logr/logr v1.2.3 h1:2DntVwHkVopvECVRSlL5PSo9eG+cAkDCuckLubN+rq0=
 github.com/go-logr/logr v1.2.3/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
 github.com/go-logr/zapr v1.2.3 h1:a9vnzlIBPQBBkeaR9IuMUfmVOrQlkoC4YfPoFkX3T7A=
+github.com/go-logr/zapr v1.2.3/go.mod h1:eIauM6P8qSvTw5o2ez6UEAfGjQKrxQTl5EoK+Qa2oG4=
 github.com/go-openapi/jsonpointer v0.19.3/go.mod h1:Pl9vOtqEWErmShwVjC8pYs9cog34VGT37dQOVbmoatg=
 github.com/go-openapi/jsonpointer v0.19.5 h1:gZr+CIYByUqjcgeLXnQu2gHYQC9o73G2XUeOFYEICuY=
 github.com/go-openapi/jsonpointer v0.19.5/go.mod h1:Pl9vOtqEWErmShwVjC8pYs9cog34VGT37dQOVbmoatg=
@@ -260,6 +264,7 @@ github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UV
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.0 h1:pSgiaMZlXftHpm5L7V1+rVB+AZJydKsMxsQBIJw4PKk=
 github.com/yuin/goldmark v1.1.25/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
@@ -271,9 +276,14 @@ go.opencensus.io v0.22.2/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.22.3/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.22.4/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.uber.org/atomic v1.7.0 h1:ADUqmZGgLDDfbSL9ZmPxKTybcoEYHgpYfELNoN+7hsw=
+go.uber.org/atomic v1.7.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
+go.uber.org/goleak v1.1.10/go.mod h1:8a7PlsEVH3e/a/GLqe5IIrQx6GzcnRmZEufDUTk4A7A=
 go.uber.org/goleak v1.2.0 h1:xqgm/S+aQvhWFTtR0XK3Jvg7z8kGV8P4X14IzwN3Eqk=
 go.uber.org/multierr v1.6.0 h1:y6IPFStTAIT5Ytl7/XYmHvzXQ7S3g/IeZW9hyZ5thw4=
+go.uber.org/multierr v1.6.0/go.mod h1:cdWPpRnG4AhwMwsgIHip0KRBQjJy5kYEpYjJxpXp9iU=
+go.uber.org/zap v1.19.0/go.mod h1:xg/QME4nWcxGxrpdeYfq7UvYrLh66cuVKdrbD1XF/NI=
 go.uber.org/zap v1.24.0 h1:FiJd5l1UOLj0wCgbSE0rwwXHzEdAZS6hiiSnxJN/D60=
+go.uber.org/zap v1.24.0/go.mod h1:2kMP+WWQ8aoFoedH3T2sq6iJ2yDWpHbP0f6MQbS9Gkg=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20190510104115-cbcb75029529/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
@@ -438,6 +448,7 @@ golang.org/x/tools v0.0.0-20190628153133-6cdbf07be9d0/go.mod h1:/rFqwRUd4F7ZHNgw
 golang.org/x/tools v0.0.0-20190816200558-6889da9d5479/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20190911174233-4f2ddba30aff/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20191012152004-8de300cfc20a/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20191108193012-7d206e10da11/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20191113191852-77e3bb0ad9e7/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20191115202509-3a792d9c32b2/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
@@ -574,6 +585,7 @@ gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=

internal/cache/cache.go

@@ -1,14 +1,11 @@
 package cache
 
-type Cache[K comparable, V any] interface {
+type MapCache[K comparable, V any] interface {
 	Read(k K) V
 	Write(k K, v V) V
 	Remove(k K)
 	Size() int
-}
 
-type MapCache[K comparable, V any] interface {
-	Cache[K, V]
 	FromMap(m map[K]V) MapCache[K, V]
 	ToMap() map[K]V
 }