feat: supports multiple namespaces for k8s (#3848)

docs/guide/k8s.md

@@ -139,6 +139,9 @@ spec:
               value: "default"
 ```
 
+> [!NOTE]
+> Dozzle supports multiple namespaces, you can set the `DOZZLE_NAMESPACES` environment variable to a comma separated list of namespaces. When multiple namespaces are specified, Dozzle will monitor each namespace separately and combine the results.
+
 ### Labels and Filters
 
 `DOZZLE_FILTER` behave similarlty to Docker filters. You can limit the scope of Dozzle using the `DOZZLE_FILTER` environment variable. For example, to scope only to `env=prod`:

internal/k8s/client.go

@@ -2,9 +2,11 @@ package k8s
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"strings"
+	"sync"
 	"time"
 
 	"os"
@@ -13,9 +15,13 @@ import (
 	"github.com/amir20/dozzle/internal/utils"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/watch"
 
 	"github.com/rs/zerolog/log"
 
+	"github.com/samber/lo"
+	lop "github.com/samber/lo/parallel"
+
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/kubernetes/scheme"
 	"k8s.io/client-go/rest"
@@ -25,15 +31,19 @@ import (
 
 type K8sClient struct {
 	Clientset *kubernetes.Clientset
-	namespace string
+	namespace []string
 	config    *rest.Config
 	host      container.Host
 }
 
-func NewK8sClient(namespace string) (*K8sClient, error) {
+func NewK8sClient(namespace []string) (*K8sClient, error) {
 	var config *rest.Config
 	var err error
 
+	if len(namespace) == 0 {
+		namespace = []string{metav1.NamespaceAll}
+	}
+
 	// Check if we're running in cluster
 	if os.Getenv("KUBERNETES_SERVICE_HOST") != "" {
 		config, err = rest.InClusterConfig()
@@ -116,15 +126,36 @@ func (k *K8sClient) ListContainers(ctx context.Context, labels container.Contain
 		}
 		log.Debug().Str("selector", selector).Msg("Listing containers with labels")
 	}
-	pods, err := k.Clientset.CoreV1().Pods(k.namespace).List(ctx, metav1.ListOptions{LabelSelector: selector})
+	containerList := lop.Map(k.namespace, func(namespace string, index int) lo.Tuple2[[]container.Container, error] {
+		pods, err := k.Clientset.CoreV1().Pods(namespace).List(ctx, metav1.ListOptions{LabelSelector: selector})
 		if err != nil {
-		return nil, err
+			return lo.T2[[]container.Container, error](nil, fmt.Errorf("failed to list pods in namespace %s: %w", namespace, err))
 		}
-
 		var containers []container.Container
 		for _, pod := range pods.Items {
 			containers = append(containers, podToContainers(&pod)...)
 		}
+		return lo.T2[[]container.Container, error](containers, nil)
+	})
+
+	var containers []container.Container
+	var lastError error
+	success := false
+	for _, t2 := range containerList {
+		items, err := t2.Unpack()
+		if err != nil {
+			log.Error().Err(err).Msg("failed to fetch containers")
+			lastError = err
+			continue
+		}
+		success = true
+		containers = append(containers, items...)
+	}
+
+	if !success {
+		return nil, lastError
+	}
+
 	return containers, nil
 }
 
@@ -193,12 +224,26 @@ func (k *K8sClient) ContainerLogsBetweenDates(ctx context.Context, id string, st
 }
 
 func (k *K8sClient) ContainerEvents(ctx context.Context, ch chan<- container.ContainerEvent) error {
-	watch, err := k.Clientset.CoreV1().Pods(k.namespace).Watch(ctx, metav1.ListOptions{})
+	watchers := lo.Map(k.namespace, func(namespace string, index int) watch.Interface {
+		watcher, err := k.Clientset.CoreV1().Pods(namespace).Watch(ctx, metav1.ListOptions{})
 		if err != nil {
-		return err
+			log.Error().Err(err).Msg("Failed to watch pods")
+			return nil
+		}
+		return watcher
+	})
+
+	if len(watchers) == 0 {
+		return errors.New("no namespaces to watch")
 	}
 
-	for event := range watch.ResultChan() {
+	wg := sync.WaitGroup{}
+	wg.Add(len(watchers))
+
+	for _, watcher := range watchers {
+		go func(w watch.Interface) {
+			defer wg.Done()
+			for event := range w.ResultChan() {
 				log.Debug().Interface("event.type", event.Type).Msg("Received kubernetes event")
 				pod, ok := event.Object.(*corev1.Pod)
 				if !ok {
@@ -225,6 +270,10 @@ func (k *K8sClient) ContainerEvents(ctx context.Context, ch chan<- container.Con
 					}
 				}
 			}
+		}(watcher)
+	}
+
+	wg.Wait()
 
 	return nil
 }

internal/k8s/stats_collector.go

@@ -7,6 +7,8 @@ import (
 	"time"
 
 	"github.com/amir20/dozzle/internal/container"
+	lop "github.com/samber/lo/parallel"
+
 	"github.com/puzpuzpuz/xsync/v4"
 	"github.com/rs/zerolog/log"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -95,9 +97,10 @@ func (sc *K8sStatsCollector) Start(parentCtx context.Context) bool {
 	for {
 		select {
 		case <-ticker.C:
-			metricList, err := sc.metrics.MetricsV1beta1().PodMetricses(sc.client.namespace).List(ctx, metav1.ListOptions{})
+			lop.ForEach(sc.client.namespace, func(item string, index int) {
+				metricList, err := sc.metrics.MetricsV1beta1().PodMetricses(item).List(ctx, metav1.ListOptions{})
 				if err != nil {
-				panic(err.Error())
+					log.Panic().Err(err).Msg("failed to get pod metrics")
 				}
 				for _, pod := range metricList.Items {
 					for _, c := range pod.Containers {
@@ -117,6 +120,7 @@ func (sc *K8sStatsCollector) Start(parentCtx context.Context) bool {
 						})
 					}
 				}
+			})
 		case <-ctx.Done():
 			return true
 		}

internal/support/cli/args.go

@@ -31,7 +31,7 @@ type Args struct {
 	Mode             string              `arg:"env:DOZZLE_MODE" default:"server" help:"sets the mode to run in (server, swarm)"`
 	TimeoutString    string              `arg:"--timeout,env:DOZZLE_TIMEOUT" default:"10s" help:"sets the timeout for docker client"`
 	Timeout          time.Duration       `arg:"-"`
-	Namespace        string              `arg:"env:DOZZLE_NAMESPACE" default:"" help:"sets the namespace to use in k8s"`
+	Namespace        []string            `arg:"env:DOZZLE_NAMESPACE" help:"sets the namespace to use in k8s"`
 	Healthcheck      *HealthcheckCmd     `arg:"subcommand:healthcheck" help:"checks if the server is running"`
 	Generate         *GenerateCmd        `arg:"subcommand:generate" help:"generates a configuration file for simple auth"`
 	Agent            *AgentCmd           `arg:"subcommand:agent" help:"starts the agent"`
@@ -72,6 +72,10 @@ func ParseArgs() (Args, interface{}) {
 		args.RemoteHost[i] = strings.TrimSpace(value)
 	}
 
+	for i, value := range args.Namespace {
+		args.Namespace[i] = strings.TrimSpace(value)
+	}
+
 	if args.TimeoutString != "" {
 		timeout, err := time.ParseDuration(args.TimeoutString)
 		if err != nil {