add option to store the loadbalancer logs

.github/workflows/k8s.yml

@@ -63,7 +63,7 @@ jobs:
     - name: Run cloud-provider-kind
       run: |
         make
-        nohup bin/cloud-provider-kind > ./_artifacts/ccm-kind.log 2>&1 &
+        nohup bin/cloud-provider-kind -v 2 --log-dir /_artifacts/loadbalancers > ./_artifacts/ccm-kind.log 2>&1 &
 
     - name: Create multi node cluster
       run: |
@@ -175,6 +175,7 @@ jobs:
       run: |
         /usr/local/bin/kind export logs --name ${{ env.KIND_CLUSTER_NAME}}  --loglevel=debug ./_artifacts/logs
         cp ./_artifacts/ccm-kind.log ./_artifacts/logs
+        cp ./_artifacts/loadbalancers/* ./_artifacts/logs
 
     - name: Upload logs
       if: always()
@@ -187,4 +188,4 @@ jobs:
       uses: mikepenz/action-junit-report@v2
       if: always()
       with:
-        report_paths: './_artifacts/*.xml'
+        report_paths: './_artifacts/*.xml'

cmd/app.go

@@ -4,24 +4,29 @@ import (
 	"context"
 	"flag"
 	"fmt"
-	"log"
 	"os"
 	"os/signal"
 	"strconv"
 	"syscall"
 
 	"k8s.io/component-base/logs"
+	"k8s.io/klog/v2"
 
+	"sigs.k8s.io/cloud-provider-kind/pkg/config"
 	"sigs.k8s.io/cloud-provider-kind/pkg/controller"
 	kindcmd "sigs.k8s.io/kind/pkg/cmd"
 )
 
 var (
-	flagV int
+	flagV         int
+	enableLogDump bool
+	logDumpDir    string
 )
 
 func init() {
 	flag.IntVar(&flagV, "v", 2, "Verbosity level")
+	flag.BoolVar(&enableLogDump, "log-dump", false, "store logs toa temporal directory or to the directory specified with log-dir flag")
+	flag.StringVar(&logDumpDir, "log-dir", "", "store logs to the specified directory")
 
 	flag.Usage = func() {
 		fmt.Fprint(os.Stderr, "Usage: cloud-provider-kind [options]\n\n")
@@ -33,7 +38,7 @@ func Main() {
 	// Parse command line flags and arguments
 	flag.Parse()
 	flag.VisitAll(func(flag *flag.Flag) {
-		log.Printf("FLAG: --%s=%q", flag.Name, flag.Value)
+		klog.Infof("FLAG: --%s=%q", flag.Name, flag.Value)
 	})
 
 	// trap Ctrl+C and call cancel on the context
@@ -51,14 +56,14 @@ func Main() {
 	go func() {
 		select {
 		case <-signalCh:
-			log.Printf("Exiting: received signal")
+			klog.Infof("Exiting: received signal")
 			cancel()
 		case <-ctx.Done():
 			// cleanup
 		}
 	}()
 
-	// initializet loggers, kind logger and klog
+	// initialize loggers, kind logger and klog
 	logger := kindcmd.NewLogger()
 	type verboser interface {
 		SetVerbosity(int)
@@ -72,5 +77,26 @@ func Main() {
 	if err != nil {
 		logger.Errorf("error setting klog verbosity to %d : %v", flagV, err)
 	}
+
+	// initialize log directory
+	if enableLogDump {
+		if logDumpDir == "" {
+			dir, err := os.MkdirTemp(os.TempDir(), "kind-provider-")
+			if err != nil {
+				klog.Fatal(err)
+			}
+			logDumpDir = dir
+		}
+
+		if _, err := os.Stat(logDumpDir); os.IsNotExist(err) {
+			if err := os.MkdirAll(logDumpDir, 0755); err != nil {
+				klog.Fatalf("directory %s does not exist", logDumpDir)
+			}
+		}
+		config.DefaultConfig.EnableLogDump = true
+		config.DefaultConfig.LogDir = logDumpDir
+		klog.Infof("**** Dumping load balancers logs to: %s", logDumpDir)
+	}
+
 	controller.New(logger).Run(ctx)
 }

pkg/config/config.go

@@ -0,0 +1,10 @@
+package config
+
+// DefaultConfig is a global variable that is initialized at startup with the flags options.
+// It can not be modified after that.
+var DefaultConfig = &Config{}
+
+type Config struct {
+	EnableLogDump bool
+	LogDir        string
+}

pkg/container/container.go

@@ -4,7 +4,9 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"os"
 	"os/exec"
+	"path"
 	"strings"
 
 	"k8s.io/klog/v2"
@@ -43,6 +45,31 @@ func init() {
 	}
 }
 
+func Logs(name string, w io.Writer) error {
+	cmd := exec.Command(containerRuntime, []string{"logs", name}...)
+	cmd.Stderr = w
+	cmd.Stdout = w
+	err := cmd.Run()
+	if err != nil {
+		return fmt.Errorf("failed to get container logs: %w", err)
+	}
+	return nil
+}
+
+func LogDump(containerName string, dir string) error {
+	f, err := os.Create(path.Join(dir, containerName+".log"))
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	err = Logs(containerName, f)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
 func Create(name string, args []string) error {
 	if err := exec.Command(containerRuntime, append([]string{"run", "--name", name}, args...)...).Run(); err != nil {
 		return err

pkg/loadbalancer/server.go

@@ -15,6 +15,7 @@ import (
 	cloudprovider "k8s.io/cloud-provider"
 	"k8s.io/klog/v2"
 	"k8s.io/utils/ptr"
+	"sigs.k8s.io/cloud-provider-kind/pkg/config"
 	"sigs.k8s.io/cloud-provider-kind/pkg/constants"
 	"sigs.k8s.io/cloud-provider-kind/pkg/container"
 )
@@ -90,6 +91,7 @@ func (s *Server) GetLoadBalancerName(ctx context.Context, clusterName string, se
 func (s *Server) EnsureLoadBalancer(ctx context.Context, clusterName string, service *v1.Service, nodes []*v1.Node) (*v1.LoadBalancerStatus, error) {
 	name := loadBalancerName(clusterName, service)
 	if !container.IsRunning(name) {
+		klog.Infof("container %s for loadbalancer is not running", name)
 		if container.Exist(name) {
 			err := container.Delete(name)
 			if err != nil {
@@ -143,6 +145,13 @@ func (s *Server) EnsureLoadBalancerDeleted(ctx context.Context, clusterName stri
 	if s.tunnelManager != nil {
 		err1 = s.tunnelManager.removeTunnels(containerName)
 	}
+	// Before deleting the load balancer store the logs if required
+	if config.DefaultConfig.EnableLogDump {
+		klog.V(2).Infof("storing logs for loadbalancer %s", containerName)
+		if err := container.LogDump(containerName, config.DefaultConfig.LogDir); err != nil {
+			klog.Infof("error trying to store logs for load balancer %s : %v", containerName, err)
+		}
+	}
 	err2 = container.Delete(containerName)
 	return errors.Join(err1, err2)
 }