kubeadm: Add the option to cleanup the tmp directory

The `tmp` is created by `kubeadm` but is never removed, the
size is expected to be expanded as time goes by.

Add one bool option to cleanup the `tmp` dir, the flag is
off by default.

Signed-off-by: Dave Chen <dave.chen@arm.com>

cmd/kubeadm/app/cmd/options/constant.go

@@ -148,4 +148,7 @@ const (
 
 	// Print the addon manifests to STDOUT instead of installing them.
 	PrintManifest = "print-manifest"
+
+	// CleanupTmpDir flag indicates whether reset will cleanup the tmp dir
+	CleanupTmpDir = "cleanup-tmp-dir"
 )

cmd/kubeadm/app/cmd/phases/reset/cleanupnode.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"path"
 	"path/filepath"
 
 	"github.com/pkg/errors"
@@ -47,6 +48,7 @@ func NewCleanupNodePhase() workflow.Phase {
 		InheritFlags: []string{
 			options.CertificatesDir,
 			options.NodeCRISocket,
+			options.CleanupTmpDir,
 		},
 	}
 }
@@ -103,7 +105,12 @@ func runCleanupNode(c workflow.RunData) error {
 	if certsDir != kubeadmapiv1.DefaultCertificatesDir {
 		klog.Warningf("[reset] WARNING: Cleaning a non-default certificates directory: %q\n", certsDir)
 	}
+
 	dirsToClean = append(dirsToClean, certsDir)
+	if r.CleanupTmpDir() {
+		tempDir := path.Join(kubeadmconstants.KubernetesDir, kubeadmconstants.TempDirForKubeadm)
+		dirsToClean = append(dirsToClean, tempDir)
+	}
 	resetConfigDir(kubeadmconstants.KubernetesDir, dirsToClean, r.DryRun())
 
 	if r.Cfg() != nil && features.Enabled(r.Cfg().FeatureGates, features.RootlessControlPlane) {

cmd/kubeadm/app/cmd/phases/reset/cleanupnode_test.go

@@ -142,6 +142,17 @@ func TestConfigDirCleaner(t *testing.T) {
 				"test-path",
 			},
 		},
+		"cleanup temp directory": {
+			setupDirs: []string{
+				"tmp",
+			},
+			setupFiles: []string{
+				"tmp/kubeadm-init-dryrun2845575027",
+			},
+			verifyExists: []string{
+				"tmp",
+			},
+		},
 	}
 
 	for name, test := range tests {
@@ -176,6 +187,7 @@ func TestConfigDirCleaner(t *testing.T) {
 			dirsToClean := []string{
 				filepath.Join(tmpDir, test.resetDir),
 				filepath.Join(tmpDir, kubeadmconstants.ManifestsSubDirName),
+				filepath.Join(tmpDir, kubeadmconstants.TempDirForKubeadm),
 			}
 			resetConfigDir(tmpDir, dirsToClean, false)
 
@@ -185,6 +197,7 @@ func TestConfigDirCleaner(t *testing.T) {
 			assertNotExists(t, filepath.Join(tmpDir, kubeadmconstants.KubeletKubeConfigFileName))
 			assertDirEmpty(t, filepath.Join(tmpDir, "manifests"))
 			assertDirEmpty(t, filepath.Join(tmpDir, "pki"))
+			assertDirEmpty(t, filepath.Join(tmpDir, "tmp"))
 
 			// Verify the files as requested by the test:
 			for _, path := range test.verifyExists {

cmd/kubeadm/app/cmd/phases/reset/data.go

@@ -36,4 +36,5 @@ type resetData interface {
 	Client() clientset.Interface
 	CertificatesDir() string
 	CRISocketPath() string
+	CleanupTmpDir() bool
 }

cmd/kubeadm/app/cmd/phases/reset/data_test.go

@@ -39,3 +39,4 @@ func (t *testData) DryRun() bool                       { return false }
 func (t *testData) Client() clientset.Interface        { return nil }
 func (t *testData) CertificatesDir() string            { return "" }
 func (t *testData) CRISocketPath() string              { return "" }
+func (t *testData) CleanupTmpDir() bool                { return false }

cmd/kubeadm/app/cmd/reset.go

@@ -19,6 +19,7 @@ package cmd
 import (
 	"fmt"
 	"io"
+	"path"
 
 	"github.com/lithammer/dedent"
 	"github.com/spf13/cobra"
@@ -65,6 +66,7 @@ type resetOptions struct {
 	ignorePreflightErrors []string
 	kubeconfigPath        string
 	dryRun                bool
+	cleanupTmpDir         bool
 }
 
 // resetData defines all the runtime information used when running the kubeadm reset workflow;
@@ -79,6 +81,7 @@ type resetData struct {
 	outputWriter          io.Writer
 	cfg                   *kubeadmapi.InitConfiguration
 	dryRun                bool
+	cleanupTmpDir         bool
 }
 
 // newResetOptions returns a struct ready for being used for creating cmd join flags.
@@ -87,6 +90,7 @@ func newResetOptions() *resetOptions {
 		certificatesDir: kubeadmapiv1.DefaultCertificatesDir,
 		forceReset:      false,
 		kubeconfigPath:  kubeadmconstants.GetAdminKubeConfigPath(),
+		cleanupTmpDir:   false,
 	}
 }
 
@@ -136,6 +140,7 @@ func newResetData(cmd *cobra.Command, options *resetOptions, in io.Reader, out i
 		outputWriter:          out,
 		cfg:                   cfg,
 		dryRun:                options.dryRun,
+		cleanupTmpDir:         options.cleanupTmpDir,
 	}, nil
 }
 
@@ -160,6 +165,10 @@ func AddResetFlags(flagSet *flag.FlagSet, resetOptions *resetOptions) {
 		&resetOptions.dryRun, options.DryRun, resetOptions.dryRun,
 		"Don't apply any changes; just output what would be done.",
 	)
+	flagSet.BoolVar(
+		&resetOptions.cleanupTmpDir, options.CleanupTmpDir, resetOptions.cleanupTmpDir,
+		fmt.Sprintf("Cleanup the %q directory", path.Join(kubeadmconstants.KubernetesDir, kubeadmconstants.TempDirForKubeadm)),
+	)
 
 	options.AddKubeConfigFlag(flagSet, &resetOptions.kubeconfigPath)
 	options.AddIgnorePreflightErrorsFlag(flagSet, &resetOptions.ignorePreflightErrors)
@@ -215,11 +224,16 @@ func (r *resetData) Cfg() *kubeadmapi.InitConfiguration {
 	return r.cfg
 }
 
-// DryRun returns the DryRun flag.
+// DryRun returns the dryRun flag.
 func (r *resetData) DryRun() bool {
 	return r.dryRun
 }
 
+// CleanupTmpDir returns the cleanupTmpDir flag.
+func (r *resetData) CleanupTmpDir() bool {
+	return r.cleanupTmpDir
+}
+
 // CertificatesDir returns the CertificatesDir.
 func (r *resetData) CertificatesDir() string {
 	return r.certificatesDir