Merge pull request #2 from pabateman/feature/add-cri-o

CRI-O support

.github/workflows/build-by-tag.yml

@@ -60,3 +60,6 @@ jobs:
         tag: ${{ github.ref }}
         overwrite: true
         file_glob: true
+
+    - name: Update new version in krew-index
+      uses: rajatjindal/krew-release-bot@v0.0.43

.krew.yaml

@@ -0,0 +1,50 @@
+apiVersion: krew.googlecontainertools.github.com/v1alpha2
+kind: Plugin
+metadata:
+  name: nsenter
+spec:
+  version: {{ .TagName }}
+  homepage: https://github.com/pabateman/kubectl-nsenter
+  shortDescription: "Run shell command in Pod's namespace on the node over SSH connection"
+  description: |
+    This plugin establishes a connection to node that's running the Pod over SSH and uses
+    nsenter to run commands in the container's namespace. You would need something
+    like this to run programs that are missing in the container image but presents on node.
+  caveats: |
+    * This plugin needs SSH access to nodes
+    * Remote user must have root access
+    * Nodes need to have 'nsenter'
+  platforms:
+  - selector:
+      matchLabels:
+        os: linux
+        arch: amd64
+    {{addURIAndSha "https://github.com/pabateman/kubectl-nsenter/releases/download/{{ .TagName }}/kubectl-nsenter-linux-amd64.tar.gz" .TagName }}
+    bin: kubectl-nsenter
+    files:
+      - from: kubectl-nsenter-linux-amd64
+        to: kubectl-nsenter
+      - from: LICENSE
+        to: .
+  - selector:
+      matchLabels:
+        os: darwin
+        arch: amd64
+    {{addURIAndSha "https://github.com/pabateman/kubectl-nsenter/releases/download/{{ .TagName }}/kubectl-nsenter-darwin-amd64.tar.gz" .TagName }}
+    bin: kubectl-nsenter
+    files:
+      - from: kubectl-nsenter-darwin-amd64
+        to: kubectl-nsenter
+      - from: LICENSE
+        to: .
+  - selector:
+      matchLabels:
+        os: darwin
+        arch: arm64
+    {{addURIAndSha "https://github.com/pabateman/kubectl-nsenter/releases/download/{{ .TagName }}/kubectl-nsenter-darwin-arm64.tar.gz" .TagName }}
+    bin: kubectl-nsenter
+    files:
+      - from: kubectl-nsenter-darwin-arm64
+        to: kubectl-nsenter
+      - from: LICENSE
+        to: .

cmd/kubectl-nsenter/main.go

@@ -13,7 +13,7 @@ import (
 func main() {
 	app := &cli.App{
 		Name:     "kubectl-nsenter",
-		Version:  "v0.1.0",
+		Version:  "v0.1.1",
 		Compiled: time.Now(),
 		Authors: []*cli.Author{
 			{
@@ -78,6 +78,11 @@ func main() {
 				DefaultText: "current shell auth sock",
 				Required:    false,
 			},
+			&cli.StringFlag{
+				Name:     "host",
+				Usage:    "override node ip",
+				Required: false,
+			},
 			&cli.StringFlag{
 				Name:     "port",
 				Aliases:  []string{"p"},

internal/nsenter/containerinfo.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 
 	"github.com/pkg/errors"
+	"github.com/urfave/cli/v2"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/tools/clientcmd"
@@ -18,41 +19,51 @@ type ContainerInfo struct {
 	ContainerRuntime string
 }
 
-func GetContainerInfo(kubeconfigFiles []string, contextOverride string, namespaceOverride string, pod string, container string) (*ContainerInfo, error) {
-
+func GetClientSet(clictx *cli.Context) (*kubernetes.Clientset, string, error) {
 	config := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(
-		&clientcmd.ClientConfigLoadingRules{Precedence: kubeconfigFiles},
+		&clientcmd.ClientConfigLoadingRules{Precedence: strings.Split(clictx.String("kubeconfig"), ":")},
 		&clientcmd.ConfigOverrides{
-			CurrentContext: contextOverride,
+			CurrentContext: clictx.String("context"),
 		})
 
-	var namespace string
-	var err error
-	if namespaceOverride == "" {
-		namespace, _, err = config.Namespace()
-		if err != nil {
-			return nil, errors.Wrap(err, "can't get current namespace")
-		}
-	} else {
-		namespace = namespaceOverride
-	}
-
 	clientConfig, err := config.ClientConfig()
 	if err != nil {
-		return nil, errors.Wrap(err, "can't build config")
+		return nil, "", errors.Wrap(err, "can't build config")
 	}
+
 	clientset, err := kubernetes.NewForConfig(clientConfig)
+	if err != nil {
+		return nil, "", errors.Wrap(err, "can't build client")
+	}
+
+	namespace, _, err := config.Namespace()
+	if err != nil {
+		return nil, "", errors.Wrap(err, "can't get current namespace")
+	}
+
+	return clientset, namespace, nil
+}
+
+func GetContainerInfo(clictx *cli.Context) (*ContainerInfo, error) {
+
+	kubeClient, namespace, err := GetClientSet(clictx)
 	if err != nil {
 		return nil, errors.Wrap(err, "can't build client")
 	}
 
-	podSpec, err := clientset.CoreV1().Pods(namespace).Get(context.TODO(), pod, metav1.GetOptions{})
+	if clictx.String("namespace") != "" {
+		namespace = clictx.String("namespace")
+	}
+
+	podSpec, err := kubeClient.CoreV1().Pods(namespace).Get(context.TODO(), clictx.Args().First(), metav1.GetOptions{})
 	if err != nil {
 		return nil, errors.Wrap(err, "can't get pod spec")
 	}
 
 	var containerID string
 	var containerRuntime string
+	container := clictx.String("container")
+
 	if container != "" {
 		for _, containerStatus := range podSpec.Status.ContainerStatuses {
 			if containerStatus.Name == container {

internal/nsenter/nsenter.go

@@ -26,27 +26,19 @@ func requestPassword(user, host string) (string, error) {
 }
 
 func Nsenter(clictx *cli.Context) error {
-	container := clictx.String("container")
-	kubeconfigPath := clictx.String("kubeconfig")
-	contextOverride := clictx.String("context")
-	namespaceOverride := clictx.String("namespace")
 	podName := clictx.Args().First()
 	if podName == "" {
 		fmt.Println("you must specify pod name!")
 		return cli.ShowAppHelp(clictx)
 	}
+
 	command := clictx.Args().Tail()
 	if len(command) == 0 {
 		fmt.Println("you must provide a command!")
 		return cli.ShowAppHelp(clictx)
 	}
-	kubeconfigFiles := strings.Split(kubeconfigPath, ":")
-	containerInfo, err := GetContainerInfo(
-		kubeconfigFiles,
-		contextOverride,
-		namespaceOverride,
-		podName,
-		container)
+
+	containerInfo, err := GetContainerInfo(clictx)
 	if err != nil {
 		return errors.WithMessage(err, "can't get container info")
 	}
@@ -74,6 +66,10 @@ func Nsenter(clictx *cli.Context) error {
 		}
 	}
 
+	if clictx.String("host") != "" {
+		containerInfo.NodeIP = clictx.String("host")
+	}
+
 	sshPort := clictx.String("port")
 	sshHost := net.JoinHostPort(containerInfo.NodeIP, sshPort)
 
@@ -112,7 +108,7 @@ func Nsenter(clictx *cli.Context) error {
 	switch containerInfo.ContainerRuntime {
 	case "docker":
 		pidDiscoverCommand = fmt.Sprintf("sudo docker inspect %s --format {{.State.Pid}}", containerInfo.ContainerID)
-	case "containerd":
+	case "containerd", "cri-o":
 		pidDiscoverCommand = fmt.Sprintf("sudo crictl inspect --output go-template --template={{.info.pid}} %s", containerInfo.ContainerID)
 	default:
 		return fmt.Errorf("unsupported container runtime")