runtimes: enable log export feature

cmd/cluster/cluster.go

@@ -48,7 +48,8 @@ func NewCmdCluster() *cobra.Command {
 		NewCmdClusterStop(),
 		NewCmdClusterDelete(),
 		NewCmdClusterList(),
-		NewCmdClusterEdit())
+		NewCmdClusterEdit(),
+	)
 
 	// add flags
 

cmd/debug/debug.go

@@ -23,6 +23,8 @@ package debug
 
 import (
 	"fmt"
+	"os"
+	"path/filepath"
 
 	"github.com/spf13/cobra"
 	"sigs.k8s.io/yaml"
@@ -34,6 +36,10 @@ import (
 	"github.com/k3d-io/k3d/v5/pkg/types"
 )
 
+var nodeName string
+var exportPath string
+var components []string
+
 // NewCmdDebug returns a new cobra command
 func NewCmdDebug() *cobra.Command {
 	cmd := &cobra.Command{
@@ -50,6 +56,42 @@ func NewCmdDebug() *cobra.Command {
 	}
 
 	cmd.AddCommand(NewCmdDebugLoadbalancer())
+	cmd.AddCommand(NewCmdExportLogs())
+	return cmd
+}
+
+func NewCmdExportLogs() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:               "export-logs CLUSTER",
+		Short:             "Export logs of a k3d cluster",
+		Long:              "Export logs of a k3d cluster for all nodes or selective nodes using filters",
+		ValidArgsFunction: util.ValidArgsAvailableClusters,
+		Run: func(cmd *cobra.Command, args []string) {
+			if len(args) == 0 || len(args[0]) == 0 {
+				l.Log().Fatalln("Cluster name is required")
+			}
+			cluster, err := client.ClusterGet(cmd.Context(), runtimes.SelectedRuntime, &types.Cluster{Name: args[0]})
+			if err != nil {
+				l.Log().Fatalln(err)
+			}
+			exportPath = filepath.Join(exportPath, fmt.Sprintf("debug-logs-%s", cluster.Name))
+			for _, node := range cluster.Nodes {
+				if nodeName == "" || nodeName == node.Name {
+					if err := runtimes.SelectedRuntime.ExportLogsFromNode(cmd.Context(), node, exportPath, components); err != nil {
+						l.Log().Fatalln(err)
+					}
+				}
+			}
+		},
+	}
+
+	cwd, err := os.Getwd()
+	if err != nil {
+		l.Log().Fatalln(err)
+	}
+
+	cmd.Flags().StringVarP(&nodeName, "node", "n", "", "Node name to export logs from")
+	cmd.Flags().StringVarP(&exportPath, "path", "p", cwd, "Path to export the logs to")
 
 	return cmd
 }

cmd/node/node.go

@@ -47,7 +47,8 @@ func NewCmdNode() *cobra.Command {
 		NewCmdNodeStop(),
 		NewCmdNodeDelete(),
 		NewCmdNodeList(),
-		NewCmdNodeEdit())
+		NewCmdNodeEdit(),
+	)
 
 	// add flags
 

pkg/runtimes/docker/docker.go

@@ -29,6 +29,7 @@ import (
 	"os"
 
 	l "github.com/k3d-io/k3d/v5/pkg/logger"
+	k3d "github.com/k3d-io/k3d/v5/pkg/types"
 )
 
 type Docker struct{}
@@ -42,6 +43,32 @@ func (d Docker) ID() string {
 	return "docker"
 }
 
+type commandInfo struct {
+	Command  []string
+	FileName string
+}
+
+var roleBasedExportPath = map[k3d.Role][]string{
+	k3d.ServerRole: {"/var/log", "/var/lib/rancher/k3s/agent/containerd/containerd.log"},
+	k3d.AgentRole:  {"/var/log", "/var/lib/rancher/k3s/agent/containerd/containerd.log"},
+}
+
+var roleBasedCommandsToExecute = map[k3d.Role][]commandInfo{
+	k3d.ServerRole: {
+		{Command: []string{"crictl", "images"}, FileName: "crictl-images.log"},
+		{Command: []string{"crictl", "ps", "-a"}, FileName: "crictl-ps.log"},
+		{Command: []string{"kubectl", "cluster-info"}, FileName: "cluster-info.log"},
+		{Command: []string{"kubectl", "version"}, FileName: "kubectl-version.log"},
+		{Command: []string{"kubectl", "get", "node", "-o", "yaml"}, FileName: "kubectl-get-node.yaml"},
+		{Command: []string{"ps", "-aef"}, FileName: "ps-aef.log"},
+	},
+	k3d.AgentRole: {
+		{Command: []string{"crictl", "images"}, FileName: "crictl-images.log"},
+		{Command: []string{"crictl", "ps", "-a"}, FileName: "crictl-ps.log"},
+		{Command: []string{"ps", "-aef"}, FileName: "ps-aef.log"},
+	},
+}
+
 // GetHost returns the docker daemon host
 func (d Docker) GetHost() string {
 	// a) docker-machine

pkg/runtimes/docker/node.go

@@ -29,6 +29,8 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"os"
+	"path/filepath"
 	"time"
 
 	"github.com/docker/docker/api/types"
@@ -493,3 +495,48 @@ func (d Docker) RenameNode(ctx context.Context, node *k3d.Node, newName string)
 
 	return docker.ContainerRename(ctx, container.ID, newName)
 }
+
+func (d Docker) ExportLogsFromNode(ctx context.Context, node *k3d.Node, dstPath string, components []string) error {
+	destinationPath := filepath.Join(dstPath, node.Name)
+
+	err := os.MkdirAll(destinationPath, os.FileMode(os.ModePerm))
+	if err != nil {
+		return fmt.Errorf("failed to create destination directory '%s': %w", destinationPath, err)
+	}
+	c, err := getNodeContainer(ctx, node)
+	if err != nil {
+		return fmt.Errorf("failed to get container for node '%s': %w", node.Name, err)
+	}
+
+	// create docker client
+	docker, err := GetDockerClient()
+	if err != nil {
+		return fmt.Errorf("failed to get docker client: %w", err)
+	}
+	defer docker.Close()
+
+	reader, err := docker.ContainerLogs(ctx, c.ID, container.LogsOptions{Details: true, ShowStdout: true, ShowStderr: true})
+	if err != nil {
+		return fmt.Errorf("failed to get logs from container '%s': %w", c.ID, err)
+	}
+	defer reader.Close()
+
+	err = readerToFile(reader, filepath.Join(dstPath, fmt.Sprintf("%s.log", node.Name)))
+	if err != nil {
+		return fmt.Errorf("failed to write logs to file: %w", err)
+	}
+
+	for _, srcPath := range roleBasedExportPath[node.Role] {
+		contentReader, _, err := docker.CopyFromContainer(ctx, c.ID, srcPath)
+		if err != nil {
+			return fmt.Errorf("failed to copy files from container '%s': %w", c.ID, err)
+		}
+		if err := untarReader(ctx, docker, c.ID, contentReader, destinationPath); err != nil {
+			return fmt.Errorf("failed to untar files from container '%s': %w", c.ID, err)
+		}
+	}
+	for _, command := range roleBasedCommandsToExecute[node.Role] {
+		d.executeCommandInContainer(ctx, docker, c.ID, command.Command, filepath.Join(destinationPath, command.FileName))
+	}
+	return nil
+}

pkg/runtimes/docker/util.go

@@ -23,11 +23,13 @@ package docker
 
 import (
 	"archive/tar"
+	"bufio"
 	"bytes"
 	"context"
 	"fmt"
 	"io"
 	"os"
+	"path/filepath"
 	"regexp"
 	"strings"
 
@@ -36,6 +38,7 @@ import (
 	"github.com/docker/cli/cli/command"
 	"github.com/docker/cli/cli/flags"
 	"github.com/docker/docker/api/types/filters"
+	"github.com/docker/docker/api/types/strslice"
 	"github.com/docker/docker/client"
 	"github.com/docker/docker/pkg/archive"
 	l "github.com/k3d-io/k3d/v5/pkg/logger"
@@ -180,6 +183,51 @@ func (d Docker) ReadFromNode(ctx context.Context, path string, node *k3d.Node) (
 	return reader, err
 }
 
+func (d Docker) executeCommandInContainer(ctx context.Context, cli client.APIClient, containerID string, command []string, outputFilePath string) error {
+	execConfig := container.ExecOptions{
+		Cmd:          strslice.StrSlice(command),
+		AttachStdout: true,
+		AttachStderr: true,
+		Tty:          false,
+	}
+
+	execIDResp, err := cli.ContainerExecCreate(ctx, containerID, execConfig)
+	if err != nil {
+		return fmt.Errorf("error creating exec instance: %v", err)
+	}
+
+	resp, err := cli.ContainerExecAttach(ctx, execIDResp.ID, container.ExecStartOptions{Tty: false})
+	if err != nil {
+		return fmt.Errorf("error attaching to exec instance: %v", err)
+	}
+	defer resp.Close()
+
+	outputFile, err := os.Create(outputFilePath)
+	if err != nil {
+		return fmt.Errorf("error creating output file: %v", err)
+	}
+	defer outputFile.Close()
+
+	writer := bufio.NewWriter(outputFile)
+
+	var stdoutBuf bytes.Buffer
+
+	_, err = io.Copy(&stdoutBuf, resp.Reader)
+	if err != nil {
+		return fmt.Errorf("Error copying stdout: %v", err)
+	}
+
+	if _, err := writer.WriteString(stdoutBuf.String()); err != nil {
+		return fmt.Errorf("Error writing stdout to file: %v", err)
+	}
+
+	if err := writer.Flush(); err != nil {
+		return fmt.Errorf("Error flushing writer: %v", err)
+	}
+
+	return nil
+}
+
 // GetDockerClient returns a docker client
 func GetDockerClient() (client.APIClient, error) {
 	dockerCli, err := command.NewDockerCli(command.WithStandardStreams())
@@ -211,3 +259,94 @@ func isAttachedToNetwork(node *k3d.Node, network string) bool {
 	}
 	return false
 }
+
+func readerToFile(reader io.Reader, target string) error {
+	file, err := os.OpenFile(target, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, os.FileMode(0600))
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	if _, err := io.Copy(file, reader); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func copyFile(tarReader *tar.Reader, target string, mode os.FileMode) error {
+	file, err := os.OpenFile(target, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, mode)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	if _, err := io.Copy(file, tarReader); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func copyOriginalContent(cli client.APIClient, ctx context.Context, containerID, linkTarget, target string) error {
+	reader, _, err := cli.CopyFromContainer(ctx, containerID, linkTarget)
+	if err != nil {
+		return err
+	}
+	defer reader.Close()
+
+	tarReader := tar.NewReader(reader)
+	header, err := tarReader.Next()
+	if err != nil {
+		return err
+	}
+
+	if header.Typeflag == tar.TypeReg {
+		if err := copyFile(tarReader, target, os.FileMode(header.Mode)); err != nil {
+			return err
+		}
+	} else if header.Typeflag == tar.TypeDir {
+		if err := untarReader(ctx, cli, containerID, reader, target); err != nil {
+			return err
+		}
+	} else {
+		return fmt.Errorf("unsupported symlink target file type: %v", header.Typeflag)
+	}
+
+	return nil
+}
+
+func untarReader(ctx context.Context, cli client.APIClient, containerID string, reader io.Reader, dstPath string) error {
+	tarReader := tar.NewReader(reader)
+
+	for {
+		header, err := tarReader.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+
+		target := filepath.Join(dstPath, header.Name)
+
+		switch header.Typeflag {
+		case tar.TypeDir:
+			if err := os.MkdirAll(target, os.FileMode(header.Mode)); err != nil {
+				return err
+			}
+		case tar.TypeReg:
+			if err := copyFile(tarReader, target, os.FileMode(header.Mode)); err != nil {
+				return err
+			}
+		case tar.TypeSymlink:
+			linkTarget := header.Linkname
+			if err := copyOriginalContent(cli, ctx, containerID, linkTarget, target); err != nil {
+				return err
+			}
+		default:
+			return fmt.Errorf("unsupported file type: %v", header.Typeflag)
+		}
+	}
+
+	return nil
+}

pkg/runtimes/runtime.go

@@ -81,6 +81,7 @@ type Runtime interface {
 	DisconnectNodeFromNetwork(context.Context, *k3d.Node, string) error // @param context, node, network name
 	Info() (*runtimeTypes.RuntimeInfo, error)
 	GetNetwork(context.Context, *k3d.ClusterNetwork) (*k3d.ClusterNetwork, error) // @param context, network (so we can filter by name or by id)
+	ExportLogsFromNode(context.Context, *k3d.Node, string, []string) error        // @param context, node, source, destination, components (This is meant for future use once we identify what/how to filter)
 }
 
 // GetRuntime checks, if a given name is represented by an implemented k3d runtime and returns it