refactor: move table rendering into own funcs

The logic for rendering tables with the checkpoint data was all present
in a single function `showContainerCheckpoint()`. This has now been
refactored to provide each table its own function that can be called to
render it. This increases code maintainability going forward as more and
more tables are added to the `checkpointctl show` command.

Signed-off-by: Prajwal S N <prajwalnadig21@gmail.com>

container.go

@@ -17,6 +17,7 @@ import (
 
 	metadata "github.com/checkpoint-restore/checkpointctl/lib"
 	"github.com/checkpoint-restore/go-criu/v6/crit"
+	"github.com/checkpoint-restore/go-criu/v6/crit/images"
 	"github.com/containers/storage/pkg/archive"
 	"github.com/olekukonko/tablewriter"
 	spec "github.com/opencontainers/runtime-spec/specs-go"
@@ -66,10 +67,6 @@ func getCRIOInfo(_ *metadata.ContainerConfig, specDump *spec.Spec) (*containerIn
 }
 
 func showContainerCheckpoint(checkpointDirectory, input string) error {
-	var (
-		row []string
-		ci  *containerInfo
-	)
 	containerConfig, _, err := metadata.ReadContainerCheckpointConfigDump(checkpointDirectory)
 	if err != nil {
 		return err
@@ -79,11 +76,15 @@ func showContainerCheckpoint(checkpointDirectory, input string) error {
 		return err
 	}
 
+	var ci *containerInfo
 	switch m := specDump.Annotations["io.container.manager"]; m {
 	case "libpod":
 		ci = getPodmanInfo(containerConfig, specDump)
 	case "cri-o":
 		ci, err = getCRIOInfo(containerConfig, specDump)
+		if err != nil {
+			return fmt.Errorf("getting container checkpoint information failed: %w", err)
+		}
 	default:
 		containerdStatus, _, _ := metadata.ReadContainerCheckpointStatusFile(checkpointDirectory)
 		if containerdStatus == nil {
@@ -92,12 +93,40 @@ func showContainerCheckpoint(checkpointDirectory, input string) error {
 		ci = getContainerdInfo(containerdStatus, specDump)
 	}
 
+	// Fetch root fs diff size if available
+	archiveSizes, err := getArchiveSizes(input)
 	if err != nil {
-		return fmt.Errorf("getting container checkpoint information failed: %w", err)
+		return fmt.Errorf("failed to get archive sizes: %w", err)
 	}
 
 	fmt.Printf("\nDisplaying container checkpoint data from %s\n\n", input)
 
+	renderCheckpoint(ci, containerConfig, archiveSizes)
+
+	if mounts {
+		renderMounts(specDump)
+	}
+
+	if stats {
+		cpDir, err := os.Open(checkpointDirectory)
+		if err != nil {
+			return err
+		}
+		defer cpDir.Close()
+
+		// Get dump statistics with crit
+		dumpStats, err := crit.GetDumpStats(cpDir.Name())
+		if err != nil {
+			return fmt.Errorf("unable to display checkpointing statistics: %w", err)
+		}
+
+		renderDumpStats(dumpStats)
+	}
+
+	return nil
+}
+
+func renderCheckpoint(ci *containerInfo, containerConfig *metadata.ContainerConfig, archiveSizes *archiveSizes) {
 	table := tablewriter.NewWriter(os.Stdout)
 	header := []string{
 		"Container",
@@ -108,6 +137,7 @@ func showContainerCheckpoint(checkpointDirectory, input string) error {
 		"Engine",
 	}
 
+	var row []string
 	row = append(row, ci.Name)
 	row = append(row, containerConfig.RootfsImageName)
 	if len(containerConfig.ID) > 12 {
@@ -129,11 +159,6 @@ func showContainerCheckpoint(checkpointDirectory, input string) error {
 		row = append(row, ci.MAC)
 	}
 
-	archiveSizes, err := getArchiveSizes(input)
-	if err != nil {
-		return err
-	}
-
 	header = append(header, "CHKPT Size")
 	row = append(row, metadata.ByteToString(archiveSizes.checkpointSize))
 
@@ -148,66 +173,52 @@ func showContainerCheckpoint(checkpointDirectory, input string) error {
 	table.SetHeader(header)
 	table.Append(row)
 	table.Render()
+}
 
-	if showMounts {
-		table = tablewriter.NewWriter(os.Stdout)
-		table.SetHeader([]string{
-			"Destination",
-			"Type",
-			"Source",
-		})
-		// Get overview of mounts from spec.dump
-		for _, data := range specDump.Mounts {
-			table.Append([]string{
-				data.Destination,
-				data.Type,
-				func() string {
-					if fullPaths {
-						return data.Source
-					}
-					return shortenPath(data.Source)
-				}(),
-			})
-		}
-		fmt.Println("\nOverview of Mounts")
-		table.Render()
-	}
-
-	if printStats {
-		cpDir, err := os.Open(checkpointDirectory)
-		if err != nil {
-			return err
-		}
-		defer cpDir.Close()
-
-		// Get dump statistics with crit
-		dumpStatistics, err := crit.GetDumpStats(cpDir.Name())
-		if err != nil {
-			return fmt.Errorf("unable to display checkpointing statistics: %w", err)
-		}
-
-		table = tablewriter.NewWriter(os.Stdout)
-		table.SetHeader([]string{
-			"Freezing Time",
-			"Frozen Time",
-			"Memdump Time",
-			"Memwrite Time",
-			"Pages Scanned",
-			"Pages Written",
-		})
+func renderMounts(specDump *spec.Spec) {
+	table := tablewriter.NewWriter(os.Stdout)
+	table.SetHeader([]string{
+		"Destination",
+		"Type",
+		"Source",
+	})
+	// Get overview of mounts from spec.dump
+	for _, data := range specDump.Mounts {
 		table.Append([]string{
-			fmt.Sprintf("%d us", dumpStatistics.GetFreezingTime()),
-			fmt.Sprintf("%d us", dumpStatistics.GetFrozenTime()),
-			fmt.Sprintf("%d us", dumpStatistics.GetMemdumpTime()),
-			fmt.Sprintf("%d us", dumpStatistics.GetMemwriteTime()),
-			fmt.Sprintf("%d", dumpStatistics.GetPagesScanned()),
-			fmt.Sprintf("%d", dumpStatistics.GetPagesWritten()),
+			data.Destination,
+			data.Type,
+			func() string {
+				if fullPaths {
+					return data.Source
+				}
+				return shortenPath(data.Source)
+			}(),
 		})
-		fmt.Println("\nCRIU dump statistics")
-		table.Render()
 	}
+	fmt.Println("\nOverview of Mounts")
+	table.Render()
+}
 
-	return nil
+func renderDumpStats(dumpStats *images.DumpStatsEntry) {
+	table := tablewriter.NewWriter(os.Stdout)
+	table.SetHeader([]string{
+		"Freezing Time",
+		"Frozen Time",
+		"Memdump Time",
+		"Memwrite Time",
+		"Pages Scanned",
+		"Pages Written",
+	})
+	table.Append([]string{
+		fmt.Sprintf("%d us", dumpStats.GetFreezingTime()),
+		fmt.Sprintf("%d us", dumpStats.GetFrozenTime()),
+		fmt.Sprintf("%d us", dumpStats.GetMemdumpTime()),
+		fmt.Sprintf("%d us", dumpStats.GetMemwriteTime()),
+		fmt.Sprintf("%d", dumpStats.GetPagesScanned()),
+		fmt.Sprintf("%d", dumpStats.GetPagesWritten()),
+	})
+	fmt.Println("\nCRIU dump statistics")
+	table.Render()
 }
 
 func hasPrefix(path, prefix string) bool {