Allow to define namespaces for Kubernetes

Use annotations instead of labels for Kubernetes
Add Kubernetes provider doc

pkg/k8s/client.go

@@ -8,6 +8,7 @@ import (
 	"github.com/crazy-max/diun/v4/pkg/utl"
 	"github.com/pkg/errors"
 	"github.com/rs/zerolog/log"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/clientcmd"
@@ -15,39 +16,46 @@ import (
 
 // Client represents an active kubernetes object
 type Client struct {
-	ctx context.Context
-	API *kubernetes.Clientset
+	ctx        context.Context
+	namespaces []string
+	API        *kubernetes.Clientset
 }
 
 // Options holds kubernetes client object options
 type Options struct {
-	Endpoint    string
-	Token       string
-	TokenFile   string
-	TLSCAFile   string
-	TLSInsecure *bool
+	Endpoint         string
+	Token            string
+	TokenFile        string
+	CertAuthFilePath string
+	TLSInsecure      *bool
+	Namespaces       []string
 }
 
 // New initializes a new Kubernetes client
 func New(opts Options) (*Client, error) {
 	var err error
-	var cl *kubernetes.Clientset
+	var api *kubernetes.Clientset
 
 	switch {
 	case os.Getenv("KUBERNETES_SERVICE_HOST") != "" && os.Getenv("KUBERNETES_SERVICE_PORT") != "":
 		log.Debug().Msgf("Creating in-cluster Kubernetes provider client %s", opts.Endpoint)
-		cl, err = newInClusterClient(opts)
+		api, err = newInClusterClient(opts)
 	case os.Getenv("KUBECONFIG") != "":
 		log.Debug().Msgf("Creating cluster-external Kubernetes provider client from KUBECONFIG %s", os.Getenv("KUBECONFIG"))
-		cl, err = newExternalClusterClientFromFile(opts, os.Getenv("KUBECONFIG"))
+		api, err = newExternalClusterClientFromFile(opts, os.Getenv("KUBECONFIG"))
 	default:
 		log.Debug().Msgf("Creating cluster-external Kubernetes provider client %s", opts.Endpoint)
-		cl, err = newExternalClusterClient(opts)
+		api, err = newExternalClusterClient(opts)
+	}
+
+	if len(opts.Namespaces) == 0 {
+		opts.Namespaces = []string{metav1.NamespaceAll}
 	}
 
 	return &Client{
-		ctx: context.Background(),
-		API: cl,
+		ctx:        context.Background(),
+		namespaces: opts.Namespaces,
+		API:        api,
 	}, err
 }
 
@@ -76,7 +84,6 @@ func newExternalClusterClientFromFile(opts Options, file string) (*kubernetes.Cl
 		configFromFlags.TLSClientConfig.Insecure = *opts.TLSInsecure
 	}
 
-	configFromFlags.TLSClientConfig.Insecure = true
 	return kubernetes.NewForConfig(configFromFlags)
 }
 
@@ -97,8 +104,8 @@ func newExternalClusterClient(opts Options) (*kubernetes.Clientset, error) {
 		BearerToken: opts.Token,
 	}
 
-	if opts.TLSCAFile != "" {
-		caData, err := ioutil.ReadFile(opts.TLSCAFile)
+	if opts.CertAuthFilePath != "" {
+		caData, err := ioutil.ReadFile(opts.CertAuthFilePath)
 		if err != nil {
 			return nil, errors.Wrap(err, "Failed to read CA file")
 		}

pkg/k8s/pod.go

@@ -9,14 +9,19 @@ import (
 
 // PodList returns Kubernetes pods
 func (c *Client) PodList(opts metav1.ListOptions) ([]v1.Pod, error) {
-	pods, err := c.API.CoreV1().Pods("").List(c.ctx, opts)
-	if err != nil {
-		return nil, err
+	var podList []v1.Pod
+
+	for _, ns := range c.namespaces {
+		pods, err := c.API.CoreV1().Pods(ns).List(c.ctx, opts)
+		if err != nil {
+			return nil, err
+		}
+		podList = append(podList, pods.Items...)
 	}
 
-	sort.Slice(pods.Items, func(i, j int) bool {
-		return pods.Items[i].Name < pods.Items[j].Name
+	sort.Slice(podList, func(i, j int) bool {
+		return podList[i].Name < podList[j].Name
 	})
 
-	return pods.Items, nil
+	return podList, nil
 }

pkg/k8s/pod_test.go

@@ -0,0 +1,37 @@
+package k8s_test
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/crazy-max/diun/v4/pkg/k8s"
+	"github.com/crazy-max/diun/v4/pkg/utl"
+	"github.com/stretchr/testify/assert"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+func TestPodList(t *testing.T) {
+	if os.Getenv("CI") != "" {
+		t.Skip("Skipping testing in CI environment")
+	}
+
+	os.Setenv("KUBECONFIG", "./.dev/minikube.config")
+
+	kc, err := k8s.New(k8s.Options{
+		TLSInsecure: utl.NewTrue(),
+	})
+	assert.NoError(t, err)
+	assert.NotNil(t, kc)
+
+	pods, err := kc.PodList(metav1.ListOptions{})
+	assert.NoError(t, err)
+	assert.NotNil(t, pods)
+	assert.True(t, len(pods) > 0)
+
+	for _, pod := range pods {
+		for _, ctn := range pod.Spec.Containers {
+			fmt.Println(pod.Name, ctn.Image)
+		}
+	}
+}