feat: Introduce support for the list command to retrieve container

      checkpoints

- If applied, this commit will introduce support for the list command
  to retrieve container checkpoints, enhance user accessibility to
  container-related information.

Signed-off-by: Parthiba-Hazra <[email protected]>

checkpointctl.go

@@ -29,6 +29,8 @@ func main() {
 
 	rootCommand.AddCommand(cmd.MemParse())
 
+	rootCommand.AddCommand(cmd.List())
+
 	rootCommand.Version = version
 
 	if err := rootCommand.Execute(); err != nil {

cmd/list.go

@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: Apache-2.0
+
+// This file is used to show the list of container checkpoints
+
+package cmd
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/checkpoint-restore/checkpointctl/internal"
+	"github.com/olekukonko/tablewriter"
+	"github.com/spf13/cobra"
+)
+
+var (
+	defaultCheckpointPath     = "/var/lib/kubelet/checkpoints/"
+	additionalCheckpointPaths []string
+)
+
+func List() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "list",
+		Short: "List checkpoints stored in the default and additional paths",
+		RunE:  list,
+	}
+
+	flags := cmd.Flags()
+	flags.StringSliceVarP(
+		&additionalCheckpointPaths,
+		"paths",
+		"p",
+		[]string{},
+		"Specify additional paths to include in checkpoint listing",
+	)
+
+	return cmd
+}
+
+func list(cmd *cobra.Command, args []string) error {
+	allPaths := append([]string{defaultCheckpointPath}, additionalCheckpointPaths...)
+	showTable := false
+
+	table := tablewriter.NewWriter(os.Stdout)
+	header := []string{
+		"Namespace",
+		"Pod",
+		"Container",
+		"Time Created",
+		"Checkpoint Name",
+	}
+
+	table.SetHeader(header)
+	table.SetAutoMergeCells(false)
+	table.SetRowLine(true)
+
+	for _, checkpointPath := range allPaths {
+		files, err := filepath.Glob(filepath.Join(checkpointPath, "checkpoint-*"))
+		if err != nil {
+			return err
+		}
+
+		if len(files) == 0 {
+			continue
+		}
+
+		showTable = true
+		fmt.Printf("Listing checkpoints in path: %s\n", checkpointPath)
+
+		for _, file := range files {
+			namespace, pod, container, timestamp, err := internal.ExtractConfigDump(file)
+			if err != nil {
+				log.Printf("Error extracting information from %s: %v\n", file, err)
+				continue
+			}
+
+			row := []string{
+				namespace,
+				pod,
+				container,
+				timestamp.Format(time.RFC822),
+				filepath.Base(file),
+			}
+
+			table.Append(row)
+		}
+	}
+
+	if showTable {
+		table.Render()
+	} else {
+		fmt.Println("No checkpoints found")
+	}
+
+	return nil
+}

docs/checkpointctl-list.adoc

@@ -0,0 +1,26 @@
+= checkpointctl-list(1)
+include::footer.adoc[]
+
+== Name
+
+*checkpointctl-list* - List checkpoints stored in the default and additional paths
+
+== Synopsis
+
+*checkpointctl list* [_OPTION_]... _FOLDER_...
+
+== Options
+
+*-h*, *--help*::
+  Show help for checkpointctl list
+
+*-p*, *--path*::
+  Specify additional paths to include in checkpoint listing
+
+== Default Path
+
+The default path for checking checkpoints is `/var/lib/kubelet/checkpoints/`.
+
+== See also
+
+checkpointctl(1)

internal/config_extractor.go

@@ -0,0 +1,55 @@
+package internal
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	metadata "github.com/checkpoint-restore/checkpointctl/lib"
+)
+
+func ExtractConfigDump(checkpointPath string) (namespace, pod, container string, timestamp time.Time, err error) {
+	tempDir, err := os.MkdirTemp("", "extracted-checkpoint")
+	if err != nil {
+		return "", "", "", time.Time{}, err
+	}
+	defer os.RemoveAll(tempDir)
+
+	filesToExtract := []string{"config.dump"}
+	if err := UntarFiles(checkpointPath, tempDir, filesToExtract); err != nil {
+		log.Printf("Error extracting files from archive %s: %v\n", checkpointPath, err)
+		return "", "", "", time.Time{}, err
+	}
+
+	configDumpPath := filepath.Join(tempDir, "config.dump")
+	content, err := os.ReadFile(configDumpPath)
+	if err != nil {
+		log.Printf("Error reading config.dump file: %v\n", err)
+		return "", "", "", time.Time{}, err
+	}
+
+	return extractConfigDumpContent(content)
+}
+
+func extractConfigDumpContent(content []byte) (namespace, pod, container string, timestamp time.Time, err error) {
+	var c metadata.ContainerConfig
+	if err := json.Unmarshal(content, &c); err != nil {
+		return "", "", "", time.Time{}, err
+	}
+
+	parts := strings.Split(c.Name, "_")
+
+	if len(parts) >= 4 {
+		container = parts[1]
+		pod = parts[2]
+		namespace = parts[3]
+	} else {
+		return "", "", "", time.Time{}, fmt.Errorf("invalid name format")
+	}
+
+	return namespace, pod, container, c.CheckpointedAt, nil
+}

internal/config_extractor_test.go

@@ -0,0 +1,51 @@
+package internal
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+)
+
+func TestExtractConfigDump(t *testing.T) {
+	tempDir, err := os.MkdirTemp("", "test-extract-config-dump")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tempDir)
+
+	checkpointFile := filepath.Join(tempDir, "checkpoint-123.tar")
+	if err := CreateTarWithFile(checkpointFile, "../test/data/list_config.dump/config.dump"); err != nil {
+		t.Fatal(err)
+	}
+
+	namespace, pod, container, timestamp, err := ExtractConfigDump(checkpointFile)
+	if err != nil {
+		t.Fatalf("ExtractConfigDump failed: %v", err)
+	}
+
+	expectedNamespace := "default"
+	expectedPod := "deployment-name"
+	expectedContainer := "container-name"
+	expectedTimestamp := time.Date(2024, 1, 28, 0, 10, 45, 673538606, time.FixedZone("", 19800))
+	if namespace != expectedNamespace || pod != expectedPod || container != expectedContainer || !timestamp.Equal(expectedTimestamp) {
+		t.Errorf("ExtractConfigDump returned unexpected values: namespace=%s, pod=%s, container=%s, timestamp=%v", namespace, pod, container, timestamp)
+	}
+}
+
+func TestExtractConfigDumpContent(t *testing.T) {
+	content := []byte(`{"id":"6924be1bd90c23f10e2667102b0ee0f74f09bba78b6661871e733cb3b1737821","name":"k8s_container-name_deployment-name_default_6975ee47-6765-45dc-9a2b-1e38d51031f7_0","checkpointedTime":"2024-01-28T00:10:45.673538606+05:30"}`)
+
+	namespace, pod, container, timestamp, err := extractConfigDumpContent(content)
+	if err != nil {
+		t.Fatalf("ExtractConfigDumpContent failed: %v", err)
+	}
+
+	expectedNamespace := "default"
+	expectedPod := "deployment-name"
+	expectedContainer := "container-name"
+	expectedTimestamp := time.Date(2024, 1, 28, 0, 10, 45, 673538606, time.FixedZone("", 19800))
+	if namespace != expectedNamespace || pod != expectedPod || container != expectedContainer || !timestamp.Equal(expectedTimestamp) {
+		t.Errorf("ExtractConfigDumpContent returned unexpected values: namespace=%s, pod=%s, container=%s, timestamp=%v", namespace, pod, container, timestamp)
+	}
+}

internal/utils.go

@@ -1,8 +1,10 @@
 package internal
 
 import (
+	"archive/tar"
 	"fmt"
 	"os"
+	"path/filepath"
 	"strings"
 	"time"
 
@@ -82,3 +84,34 @@ func CleanupTasks(tasks []Task) {
 		}
 	}
 }
+
+func CreateTarWithFile(tarPath string, filePath string) error {
+	file, err := os.Create(tarPath)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	tarWriter := tar.NewWriter(file)
+	defer tarWriter.Close()
+
+	fileInfo, err := os.Stat(filePath)
+	if err != nil {
+		return err
+	}
+	header, err := tar.FileInfoHeader(fileInfo, "")
+	if err != nil {
+		return err
+	}
+	header.Name = filepath.Base(filePath)
+	if err := tarWriter.WriteHeader(header); err != nil {
+		return err
+	}
+	content, err := os.ReadFile(filePath)
+	if err != nil {
+		return err
+	}
+	if _, err := tarWriter.Write(content); err != nil {
+		return err
+	}
+	return nil
+}

test/checkpointctl.bats

@@ -640,3 +640,43 @@ function teardown() {
 	run bash -c "$CHECKPOINTCTL inspect $TEST_TMP_DIR2/test.tar --format=json --sockets | test_socket_src_port"
 	[ "$status" -eq 0 ]
 }
+
+@test "Run checkpointctl list with empty directory" {
+    mkdir "$TEST_TMP_DIR1"/empty
+    checkpointctl list -p "$TEST_TMP_DIR1"/empty/
+    [ "$status" -eq 0 ]
+    [[ ${lines[0]} == *"No checkpoints found"* ]]
+}
+
+@test "Run checkpointctl list with non existing directory" {
+	checkpointctl list -p /does-not-exist
+	[ "$status" -eq 0 ]
+	[[ ${lines[0]} == *"No checkpoints found"* ]]
+}
+
+@test "Run checkpointctl list with empty tar file" {
+	touch "$TEST_TMP_DIR1"/checkpoint-nginx-empty.tar
+	checkpointctl list -p "$TEST_TMP_DIR1"/
+	[ "$status" -eq 0 ]
+	[[ "${lines[1]}" == *"Error reading config.dump file"* ]]
+	[[ "${lines[2]}" == *"Error extracting information"* ]]
+}
+
+@test "Run checkpointctl list with tar file with empty config.dump" {
+	touch "$TEST_TMP_DIR1"/config.dump
+	mkdir "$TEST_TMP_DIR1"/checkpoint
+	( cd "$TEST_TMP_DIR1" && tar cf "$TEST_TMP_DIR2"/checkpoint-empty-config.tar . )
+	checkpointctl list -p "$TEST_TMP_DIR2"
+	[ "$status" -eq 0 ]
+	[[ ${lines[1]} == *"Error extracting information from $TEST_TMP_DIR2/checkpoint-empty-config.tar: unexpected end of JSON input" ]]
+}
+
+@test "Run checkpointctl list with tar file with valid config.dump" {
+	cp data/list_config.dump/config.dump "$TEST_TMP_DIR1"
+	mkdir "$TEST_TMP_DIR1"/checkpoint
+	( cd "$TEST_TMP_DIR1" && tar cf "$TEST_TMP_DIR2"/checkpoint-valid-config.tar . )
+	checkpointctl list -p "$TEST_TMP_DIR2"
+	[ "$status" -eq 0 ]
+	[[ "${lines[4]}" == *"| default   | deployment-name | container-name |"* ]]
+	[[ "${lines[4]}" == *"| checkpoint-valid-config.tar |"* ]]
+}

test/data/list_config.dump/config.dump

@@ -0,0 +1,12 @@
+{
+  "id": "6924be1bd90c23f10e2667102b0ee0f74f09bba78b6661871e733cb3b1737821",
+  "name": "k8s_container-name_deployment-name_default_6975ee47-6765-45dc-9a2b-1e38d51031f7_0",
+  "rootfsImage": "docker.io/library/nginx@sha256:161ef4b1bf7effb350a2a9625cb2b59f69d54ec6059a8a155a1438d0439c593c",
+  "rootfsImageRef": "a8758716bb6aa4d90071160d27028fe4eaee7ce8166221a97d30440c8eac2be6",
+  "rootfsImageName": "docker.io/library/nginx:latest",
+  "runtime": "runc",
+  "createdTime": "2024-01-27T14:45:26.083444055Z",
+  "checkpointedTime": "2024-01-28T00:10:45.673538606+05:30",
+  "restoredTime": "0001-01-01T00:00:00Z",
+  "restored": false
+}