From: Adrian Reber <areber@redhat.com>
Date: Sat, 2 Aug 2025 13:08:20 +0000
Subject: Replace olekukonko/tablewriter with text/tabwriter

Drop external tablewriter dependency in favor of Go's built-in text/tabwriter
package to reduce dependencies and simplify maintenance.

Changes:
- Replace tablewriter.NewWriter() with tabwriter.NewWriter() in all table
  display functions
- Update table formatting logic to use tab-separated output with headers
  and separator lines
- Remove olekukonko/tablewriter and related dependencies from go.mod
- Update test expectations to match new table output format
- Fix test line number references after table format changes

All tests pass with the new implementation.

Assisted-by: Claude AI for dependency replacement and test updates
Signed-off-by: Adrian Reber <areber@redhat.com>
Signed-off-by: Radostin Stoyanov <rstoyano@redhat.com>
---
 README.md               | 36 +++++++++++++++++-----------------
 cmd/list.go             | 14 +++++++-------
 cmd/memparse.go         | 50 +++++++++++++++++++++++++-----------------------
 internal/container.go   | 15 ++++++++-------
 internal/utils.go       | 51 +++++++++++++++++++++++++++++++++++++++++++++++++
 test/checkpointctl.bats | 30 +++++++++++++++++------------
 6 files changed, 127 insertions(+), 69 deletions(-)

diff --git a/README.md b/README.md
index 9c4320f..99b2a98 100644
--- a/README.md
+++ b/README.md
@@ -30,24 +30,25 @@ To display an overview of a checkpoint archive you can just use
 ```console
 $ checkpointctl show /tmp/dump.tar
 
-+-----------------+------------------------------------------+--------------+---------+----------------------+--------+------------+-------------------+
-|    CONTAINER    |                  IMAGE                   |      ID      | RUNTIME |       CREATED        | ENGINE | CHKPT SIZE | ROOT FS DIFF SIZE |
-+-----------------+------------------------------------------+--------------+---------+----------------------+--------+------------+-------------------+
-| magical_murdock | quay.io/adrianreber/wildfly-hello:latest | f11d11844af0 | crun    | 2023-02-28T09:43:52Z | Podman | 338.2 MiB  | 177.0 KiB         |
-+-----------------+------------------------------------------+--------------+---------+----------------------+--------+------------+-------------------+
+Displaying container checkpoint data from /root/dump.tar
+
+CONTAINER  IMAGE                             ID            RUNTIME  CREATED               ENGINE  CHKPT SIZE ROOT FS DIFF SIZE
+---------  -----                             --            -------  -------               ------  ---------- -----------------
+looper     docker.io/library/busybox:latest  8b5c2ca15082  crun     2021-09-28T10:03:56Z  Podman  130.8 KiB  204 B
 ```
 
 For a checkpoint archive created by Kubernetes with *CRI-O* the output would
 look like this:
 
 ```console
-$ checkpointctl show /var/lib/kubelet/checkpoints/checkpoint-counters_default-counter-2023-02-13T16\:20\:09Z.tar
+$ checkpointctl show /var/lib/kubelet/checkpoints/checkpoint-counters_default-counter-2025-05-22T14\:31\:35Z.tar
+
+Displaying container checkpoint data from /var/lib/kubelet/checkpoints/checkpoint-counters_default-counter-2025-05-22T14:31:35Z.tar
+
+CONTAINER  IMAGE                               ID            RUNTIME  CREATED                         ENGINE  IP         CHKPT SIZE  ROOT FS DIFF SIZE
+---------  -----                               --            -------  -------                         ------  --         ----------  -----------------
+counter    quay.io/adrianreber/counter:latest  29ed106ef467  runc     2025-05-22T14:31:24.818422898Z  CRI-O   10.0.0.70  9.2 MiB     2.0 KiB
 
-+-----------+------------------------------------+--------------+---------+--------------------------------+--------+------------+------------+
-| CONTAINER |               IMAGE                |      ID      | RUNTIME |            CREATED             | ENGINE |     IP     | CHKPT SIZE |
-+-----------+------------------------------------+--------------+---------+--------------------------------+--------+------------+------------+
-| counter   | quay.io/adrianreber/counter:latest | 7eb9680287f1 | runc    | 2023-02-13T16:12:25.843774934Z | CRI-O  | 10.88.0.24 | 8.5 MiB    |
-+-----------+------------------------------------+--------------+---------+--------------------------------+--------+------------+------------+
 ```
 
 ### `inspect` sub-command
@@ -88,7 +89,7 @@ $ checkpointctl memparse /tmp/jira.tar.gz  --pid=1 | less
 
 Displaying memory pages content for Process ID 1 from checkpoint: /tmp/jira.tar.gz
 
-Address           Hexadecimal                                       ASCII
+ADDRESS           HEXADECIMAL                                       ASCII
 -------------------------------------------------------------------------------------
 00005633bb080000  f3 0f 1e fa 48 83 ec 08 48 8b 05 d1 4f 00 00 48  |....H...H...O..H|
 00005633bb080010  85 c0 74 02 ff d0 48 83 c4 08 c3 00 00 00 00 00  |..t...H.........|
@@ -145,13 +146,10 @@ $ sudo checkpointctl memparse /tmp/jira.tar.gz
 
 Displaying processes memory sizes from /tmp/jira.tar.gz
 
-+-----+--------------+-------------+
-| PID | PROCESS NAME | MEMORY SIZE |
-+-----+--------------+-------------+
-|   1 | tini         | 100.0 KiB   |
-+-----+--------------+-------------+
-|   2 | java         | 553.5 MiB   |
-+-----+--------------+-------------+
+PID  PROCESS NAME  MEMORY SIZE  SHARED MEMORY SIZE
+---  ------------  -----------  ------------------
+1    tini          100.0 KiB    0 B
+2    java          553.5 MiB    0 B
 ```
 
 In this example, given the large size of the java process, it is better to write its output to a file.
diff --git a/cmd/list.go b/cmd/list.go
index a562a54..f3f280c 100644
--- a/cmd/list.go
+++ b/cmd/list.go
@@ -12,7 +12,6 @@ import (
 	"time"
 
 	"github.com/checkpoint-restore/checkpointctl/internal"
-	"github.com/olekukonko/tablewriter"
 	"github.com/spf13/cobra"
 )
 
@@ -38,7 +37,7 @@ func list(cmd *cobra.Command, args []string) error {
 	}()
 	showTable := false
 
-	table := tablewriter.NewWriter(os.Stdout)
+	w := internal.GetNewTabWriter(os.Stdout)
 	header := []string{
 		"Namespace",
 		"Pod",
@@ -48,9 +47,7 @@ func list(cmd *cobra.Command, args []string) error {
 		"Checkpoint Name",
 	}
 
-	table.SetHeader(header)
-	table.SetAutoMergeCells(false)
-	table.SetRowLine(true)
+	var rows [][]string
 
 	for _, checkpointPath := range allPaths {
 		files, err := filepath.Glob(filepath.Join(checkpointPath, "checkpoint-*"))
@@ -81,7 +78,7 @@ func list(cmd *cobra.Command, args []string) error {
 				filepath.Base(file),
 			}
 
-			table.Append(row)
+			rows = append(rows, row)
 		}
 	}
 
@@ -90,6 +87,9 @@ func list(cmd *cobra.Command, args []string) error {
 		return nil
 	}
 
-	table.Render()
+	internal.WriteTableHeader(w, header)
+	internal.WriteTableRows(w, rows)
+
+	w.Flush()
 	return nil
 }
diff --git a/cmd/memparse.go b/cmd/memparse.go
index 8f69ec1..51c85fb 100644
--- a/cmd/memparse.go
+++ b/cmd/memparse.go
@@ -14,7 +14,6 @@ import (
 	"github.com/checkpoint-restore/checkpointctl/internal"
 	metadata "github.com/checkpoint-restore/checkpointctl/lib"
 	"github.com/checkpoint-restore/go-criu/v7/crit"
-	"github.com/olekukonko/tablewriter"
 	"github.com/spf13/cobra"
 )
 
@@ -116,21 +115,16 @@ func memparse(cmd *cobra.Command, args []string) error {
 
 // Display processes memory sizes within the given container checkpoints.
 func showProcessMemorySizeTables(tasks []internal.Task) error {
-	// Initialize the table
-	table := tablewriter.NewWriter(os.Stdout)
 	header := []string{
 		"PID",
 		"Process name",
 		"Memory size",
 		"Shared memory size",
 	}
-	table.SetHeader(header)
-	table.SetAutoMergeCells(false)
-	table.SetRowLine(true)
 
 	// Function to recursively traverse the process tree and populate the table rows
-	var traverseTree func(*crit.PsTree, string) error
-	traverseTree = func(root *crit.PsTree, checkpointOutputDir string) error {
+	var traverseTree func(*crit.PsTree, string, *[][]string) error
+	traverseTree = func(root *crit.PsTree, checkpointOutputDir string, rows *[][]string) error {
 		memReader, err := crit.NewMemoryReader(
 			filepath.Join(checkpointOutputDir, metadata.CheckpointDirectory),
 			root.PID, pageSize,
@@ -152,15 +146,16 @@ func showProcessMemorySizeTables(tasks []internal.Task) error {
 			return err
 		}
 
-		table.Append([]string{
+		row := []string{
 			fmt.Sprintf("%d", root.PID),
 			root.Comm,
 			metadata.ByteToString(memSize),
 			metadata.ByteToString(shmemSize),
-		})
+		}
+		*rows = append(*rows, row)
 
 		for _, child := range root.Children {
-			if err := traverseTree(child, checkpointOutputDir); err != nil {
+			if err := traverseTree(child, checkpointOutputDir, rows); err != nil {
 				return err
 			}
 		}
@@ -168,8 +163,8 @@ func showProcessMemorySizeTables(tasks []internal.Task) error {
 	}
 
 	for _, task := range tasks {
-		// Clear the table before processing each checkpoint task
-		table.ClearRows()
+		w := internal.GetNewTabWriter(os.Stdout)
+		var rows [][]string
 
 		c := crit.New(nil, nil, filepath.Join(task.OutputDir, "checkpoint"), false, false)
 		psTree, err := c.ExplorePs()
@@ -178,12 +173,16 @@ func showProcessMemorySizeTables(tasks []internal.Task) error {
 		}
 
 		// Populate the table rows
-		if err := traverseTree(psTree, task.OutputDir); err != nil {
+		if err := traverseTree(psTree, task.OutputDir, &rows); err != nil {
 			return err
 		}
 
 		fmt.Printf("\nDisplaying processes memory sizes from %s\n\n", task.CheckpointFilePath)
-		table.Render()
+
+		internal.WriteTableHeader(w, header)
+		internal.WriteTableRows(w, rows)
+
+		w.Flush()
 	}
 
 	return nil
@@ -348,21 +347,24 @@ func printMemorySearchResultForPID(task internal.Task) error {
 		return nil
 	}
 
-	table := tablewriter.NewWriter(os.Stdout)
-	table.SetHeader([]string{"Address", "Match", "Instance"})
-	table.SetAutoMergeCells(false)
-	table.SetRowLine(true)
+	w := internal.GetNewTabWriter(os.Stdout)
+	header := []string{"Address", "Match", "Instance"}
 
+	internal.WriteTableHeader(w, header)
+
+	// Build rows
+	var rows [][]string
 	for i, result := range results {
-		table.Append([]string{
-			fmt.Sprintf(
-				"%016x", result.Vaddr),
+		row := []string{
+			fmt.Sprintf("%016x", result.Vaddr),
 			result.Match,
 			fmt.Sprintf("%d", i+1),
-		})
+		}
+		rows = append(rows, row)
 	}
 
-	table.Render()
+	internal.WriteTableRows(w, rows)
 
+	w.Flush()
 	return nil
 }
diff --git a/internal/container.go b/internal/container.go
index 791785d..ace2e56 100644
--- a/internal/container.go
+++ b/internal/container.go
@@ -18,7 +18,6 @@ import (
 	metadata "github.com/checkpoint-restore/checkpointctl/lib"
 	"github.com/checkpoint-restore/go-criu/v7/crit"
 	"github.com/containers/storage/pkg/archive"
-	"github.com/olekukonko/tablewriter"
 	spec "github.com/opencontainers/runtime-spec/specs-go"
 )
 
@@ -107,7 +106,8 @@ func getCheckpointInfo(task Task) (*checkpointInfo, error) {
 }
 
 func ShowContainerCheckpoints(tasks []Task) error {
-	table := tablewriter.NewWriter(os.Stdout)
+	w := GetNewTabWriter(os.Stdout)
+
 	header := []string{
 		"Container",
 		"Image",
@@ -121,6 +121,8 @@ func ShowContainerCheckpoints(tasks []Task) error {
 		header = append(header, "IP", "MAC", "CHKPT Size", "Root Fs Diff Size")
 	}
 
+	var rows [][]string
+
 	for _, task := range tasks {
 		info, err := getCheckpointInfo(task)
 		if err != nil {
@@ -167,14 +169,13 @@ func ShowContainerCheckpoints(tasks []Task) error {
 			row = append(row, metadata.ByteToString(info.archiveSizes.rootFsDiffTarSize))
 		}
 
-		table.Append(row)
+		rows = append(rows, row)
 	}
 
-	table.SetHeader(header)
-	table.SetAutoMergeCells(false)
-	table.SetRowLine(true)
-	table.Render()
+	WriteTableHeader(w, header)
+	WriteTableRows(w, rows)
 
+	w.Flush()
 	return nil
 }
 
diff --git a/internal/utils.go b/internal/utils.go
index fc70d9b..1aeb779 100644
--- a/internal/utils.go
+++ b/internal/utils.go
@@ -2,8 +2,10 @@ package internal
 
 import (
 	"fmt"
+	"io"
 	"os"
 	"strings"
+	"text/tabwriter"
 	"time"
 
 	metadata "github.com/checkpoint-restore/checkpointctl/lib"
@@ -82,3 +84,52 @@ func CleanupTasks(tasks []Task) {
 		}
 	}
 }
+
+// Constant values are based on kubectl's tabwriter settings:
+// https://github.com/kubernetes/cli-runtime/blob/master/pkg/printers/tabwriter.go
+const (
+	tabwriterMinWidth = 6
+	tabwriterWidth    = 4
+	tabwriterPadding  = 3
+	tabwriterPadChar  = ' '
+	tabwriterFlags    = 0
+)
+
+// GetNewTabWriter returns a tabwriter that translates tabbed columns in input into properly aligned text.
+func GetNewTabWriter(output io.Writer) *tabwriter.Writer {
+	return tabwriter.NewWriter(output, tabwriterMinWidth, tabwriterWidth, tabwriterPadding, tabwriterPadChar, tabwriterFlags)
+}
+
+// WriteTableHeader writes the header row and separator line for a table
+func WriteTableHeader(w *tabwriter.Writer, header []string) {
+	// Print header
+	for i, h := range header {
+		if i > 0 {
+			fmt.Fprint(w, "\t")
+		}
+		fmt.Fprint(w, strings.ToUpper(h))
+	}
+	fmt.Fprintln(w)
+
+	// Print separator line
+	for i := range header {
+		if i > 0 {
+			fmt.Fprint(w, "\t")
+		}
+		fmt.Fprint(w, strings.Repeat("-", len(header[i])))
+	}
+	fmt.Fprintln(w)
+}
+
+// WriteTableRows writes the data rows for a table
+func WriteTableRows(w *tabwriter.Writer, rows [][]string) {
+	for _, row := range rows {
+		for i, cell := range row {
+			if i > 0 {
+				fmt.Fprint(w, "\t")
+			}
+			fmt.Fprint(w, cell)
+		}
+		fmt.Fprintln(w)
+	}
+}
diff --git a/test/checkpointctl.bats b/test/checkpointctl.bats
index 9f3fe15..ca43641 100644
--- a/test/checkpointctl.bats
+++ b/test/checkpointctl.bats
@@ -92,7 +92,7 @@ function teardown() {
 	( cd "$TEST_TMP_DIR1" && tar cf "$TEST_TMP_DIR2"/test.tar . )
 	checkpointctl show "$TEST_TMP_DIR2"/test.tar
 	[ "$status" -eq 0 ]
-	[[ ${lines[4]} == *"Podman"* ]]
+	[[ ${lines[3]} == *"Podman"* ]]
 }
 
 @test "Run checkpointctl show with tar file from containerd with valid config.dump and valid spec.dump and checkpoint directory" {
@@ -102,7 +102,7 @@ function teardown() {
 	( cd "$TEST_TMP_DIR1" && tar cf "$TEST_TMP_DIR2"/test.tar . )
 	checkpointctl show "$TEST_TMP_DIR2"/test.tar
 	[ "$status" -eq 0 ]
-	[[ ${lines[4]} == *"containerd"* ]]
+	[[ ${lines[3]} == *"containerd"* ]]
 }
 
 @test "Run checkpointctl show with tar file with valid config.dump and valid spec.dump (CRI-O) and no checkpoint directory" {
@@ -121,7 +121,7 @@ function teardown() {
 	( cd "$TEST_TMP_DIR1" && tar cf "$TEST_TMP_DIR2"/test.tar . )
 	checkpointctl show "$TEST_TMP_DIR2"/test.tar
 	[ "$status" -eq 0 ]
-	[[ ${lines[4]} == *"CRI-O"* ]]
+	[[ ${lines[3]} == *"CRI-O"* ]]
 }
 
 @test "Run checkpointctl show with tar file compressed" {
@@ -131,7 +131,7 @@ function teardown() {
 	( cd "$TEST_TMP_DIR1" && tar czf "$TEST_TMP_DIR2"/test.tar.gz . )
 	checkpointctl show "$TEST_TMP_DIR2"/test.tar.gz
 	[ "$status" -eq 0 ]
-	[[ ${lines[4]} == *"Podman"* ]]
+	[[ ${lines[3]} == *"Podman"* ]]
 }
 
 @test "Run checkpointctl show with tar file corrupted" {
@@ -165,7 +165,7 @@ function teardown() {
 	( cd "$TEST_TMP_DIR1" && tar cf "$TEST_TMP_DIR2"/test.tar . )
 	checkpointctl show "$TEST_TMP_DIR2"/test.tar
 	[ "$status" -eq 0 ]
-	[[ ${lines[2]} == *"ROOT FS DIFF SIZE"* ]]
+	[[ ${lines[1]} == *"ROOT FS DIFF SIZE"* ]]
 }
 
 @test "Run checkpointctl show with multiple tar files" {
@@ -175,8 +175,8 @@ function teardown() {
 	( cd "$TEST_TMP_DIR1" && tar cf "$TEST_TMP_DIR2"/test1.tar .  && tar cf "$TEST_TMP_DIR2"/test2.tar . )
 	checkpointctl show "$TEST_TMP_DIR2"/*.tar
 	[ "$status" -eq 0 ]
+	[[ ${lines[2]} == *"Podman"* ]]
 	[[ ${lines[3]} == *"Podman"* ]]
-	[[ ${lines[5]} == *"Podman"* ]]
 }
 
 @test "Run checkpointctl inspect with invalid format" {
@@ -546,7 +546,7 @@ function teardown() {
 	( cd "$TEST_TMP_DIR1" && tar cf "$TEST_TMP_DIR2"/test.tar . )
 	checkpointctl memparse "$TEST_TMP_DIR2"/test.tar
 	[ "$status" -eq 0 ]
-	[[ ${lines[4]} == *"piggie"* ]]
+	[[ ${lines[3]} == *"piggie"* ]]
 }
 
 @test "Run checkpointctl memparse with tar file and missing pstree.img" {
@@ -644,7 +644,7 @@ function teardown() {
 	( cd "$TEST_TMP_DIR1" && tar cf "$TEST_TMP_DIR2"/test.tar . )
 	checkpointctl memparse --search-regex='HOME=([^?]+)' "$TEST_TMP_DIR2"/test.tar --pid=1
 	[ "$status" -eq 0 ]
-	[[ ${lines[3]} == *"HOME"* ]]
+	[[ ${lines[2]} == *"HOME"* ]]
 }
 
 @test "Run checkpointctl memparse with tar file and invalid PID" {
@@ -763,8 +763,14 @@ function teardown() {
 	( cd "$TEST_TMP_DIR1" && tar cf "$TEST_TMP_DIR2"/checkpoint-valid-config-modified.tar . )
 	checkpointctl list "$TEST_TMP_DIR2"
 	[ "$status" -eq 0 ]
-	[[ "${lines[4]}" == *"| default   | modified-pod-name | container-name | CRI-O  |"* ]]
-	[[ "${lines[4]}" == *"| checkpoint-valid-config-modified.tar |"* ]]
-	[[ "${lines[6]}" == *"| default   | pod-name          | container-name | CRI-O  |"* ]]
-	[[ "${lines[6]}" == *"| checkpoint-valid-config.tar          |"* ]]
+	[[ "${lines[3]}" == *"default"* ]]
+	[[ "${lines[3]}" == *"modified-pod-name"* ]]
+	[[ "${lines[3]}" == *"container-name"* ]]
+	[[ "${lines[3]}" == *"CRI-O"* ]]
+	[[ "${lines[3]}" == *"checkpoint-valid-config-modified.tar"* ]]
+	[[ "${lines[4]}" == *"default"* ]]
+	[[ "${lines[4]}" == *"pod-name"* ]]
+	[[ "${lines[4]}" == *"container-name"* ]]
+	[[ "${lines[4]}" == *"CRI-O"* ]]
+	[[ "${lines[4]}" == *"checkpoint-valid-config.tar"* ]]
 }