Implement velero debug (#4022)

This PR added a subcommand `velero debug`, which leverages `crashd` to
collect logs and specs of velero server components and bundle them in a
tarball.

Signed-off-by: Daniel Jiang <jiangd@vmware.com>

pkg/cmd/cli/debug/debug.go

@@ -0,0 +1,199 @@
+/*
+Copyright the Velero contributors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package debug
+
+import (
+	"bytes"
+	"context"
+	_ "embed"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
+	"github.com/vmware-tanzu/crash-diagnostics/exec"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/tools/clientcmd"
+
+	"github.com/vmware-tanzu/velero/pkg/client"
+	"github.com/vmware-tanzu/velero/pkg/cmd"
+)
+
+//go:embed cshd-scripts/velero.cshd
+var scriptBytes []byte
+
+type option struct {
+	// workdir for crashd will be $baseDir/velero-debug
+	baseDir string
+	// the namespace where velero server is installed
+	namespace string
+	// the absolute path for the log bundle to be generated
+	outputPath string
+	// the absolute path for the kubeconfig file that will be read by crashd for calling K8S API
+	kubeconfigPath string
+	// the kubecontext to be used for calling K8S API
+	kubeContext string
+	// optional, the name of the backup resource whose log will be packaged into the debug bundle
+	backup string
+	// optional, the name of the restore resource whose log will be packaged into the debug bundle
+	restore string
+	// optional, it controls whether to print the debug log messages when calling crashd
+	verbose bool
+}
+
+func (o *option) bindFlags(flags *pflag.FlagSet) {
+	flags.StringVar(&o.outputPath, "output", "", "The path of the bundle tarball, by default it's ./bundle-<YYYY>-<MM>-<DD>-<HH>-<MM>-<SS>.tar.gz. Optional")
+	flags.StringVar(&o.backup, "backup", "", "The name of the backup resource whose log will be collected, no backup logs will be collected if it's not set. Optional")
+	flags.StringVar(&o.restore, "restore", "", "The name of the restore resource whose log will be collected, no restore logs will be collected if it's not set. Optional")
+	flags.BoolVar(&o.verbose, "verbose", false, "When it's set to true the debug messages by crashd will be printed during execution.  Default value is false.")
+}
+
+func (o *option) asCrashdArgs() string {
+	return fmt.Sprintf("output=%s,namespace=%s,basedir=%s,backup=%s,restore=%s,kubeconfig=%s,kubecontext=%s",
+		o.outputPath, o.namespace, o.baseDir, o.backup, o.restore, o.kubeconfigPath, o.kubeContext)
+}
+
+func (o *option) asCrashdArgMap() exec.ArgMap {
+	return exec.ArgMap{
+		"output":      o.outputPath,
+		"namespace":   o.namespace,
+		"basedir":     o.baseDir,
+		"backup":      o.backup,
+		"restore":     o.restore,
+		"kubeconfig":  o.kubeconfigPath,
+		"kubecontext": o.kubeContext,
+	}
+}
+
+func (o *option) complete(f client.Factory, fs *pflag.FlagSet) error {
+	if len(o.outputPath) == 0 {
+		o.outputPath = fmt.Sprintf("./bundle-%s.tar.gz", time.Now().Format("2006-01-02-15-04-05"))
+	}
+	absOutputPath, err := filepath.Abs(o.outputPath)
+	if err != nil {
+		return fmt.Errorf("invalid output path: %v", err)
+	}
+	o.outputPath = absOutputPath
+	tmpDir, err := ioutil.TempDir("", "crashd")
+	if err != nil {
+		return err
+	}
+	o.baseDir = tmpDir
+	o.namespace = f.Namespace()
+	kp, kc := kubeconfigAndContext(fs)
+	o.kubeconfigPath, err = filepath.Abs(kp)
+	if err != nil {
+		return fmt.Errorf("invalid kubeconfig path: %s, %v", kp, err)
+	}
+	o.kubeContext = kc
+	return nil
+}
+
+func (o *option) validate(f client.Factory) error {
+	kubeClient, err := f.KubeClient()
+	if err != nil {
+		return err
+	}
+	l, err := kubeClient.AppsV1().Deployments(o.namespace).List(context.TODO(), metav1.ListOptions{
+		LabelSelector: "component=velero",
+	})
+	if err != nil {
+		return errors.Wrap(err, "failed to check velero deployment")
+	}
+	if len(l.Items) == 0 {
+		return fmt.Errorf("velero deployment does not exist in namespace: %s", o.namespace)
+	}
+	veleroClient, err := f.Client()
+	if err != nil {
+		return err
+	}
+	if len(o.backup) > 0 {
+		if _, err := veleroClient.VeleroV1().Backups(o.namespace).Get(context.TODO(), o.backup, metav1.GetOptions{}); err != nil {
+			return err
+		}
+	}
+	if len(o.restore) > 0 {
+		if _, err := veleroClient.VeleroV1().Restores(o.namespace).Get(context.TODO(), o.restore, metav1.GetOptions{}); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// NewCommand creates a cobra command.
+func NewCommand(f client.Factory) *cobra.Command {
+	o := &option{}
+	c := &cobra.Command{
+		Use:   "debug",
+		Short: "Generate debug bundle",
+		Long: `Generate a tarball containing the logs of velero deployment, plugin logs, restic DaemonSet, 
+specs of resources created by velero server, and optionally the logs of backup and restore.`,
+		Run: func(c *cobra.Command, args []string) {
+			flags := c.Flags()
+			err := o.complete(f, flags)
+			cmd.CheckError(err)
+			defer func(opt *option) {
+				if len(opt.baseDir) > 0 {
+					if err := os.RemoveAll(opt.baseDir); err != nil {
+						fmt.Fprintf(os.Stderr, "Failed to remove temp dir: %s: %v\n", opt.baseDir, err)
+					}
+				}
+			}(o)
+			err = o.validate(f)
+			cmd.CheckError(err)
+			err = runCrashd(o)
+			cmd.CheckError(err)
+		},
+	}
+	o.bindFlags(c.Flags())
+	return c
+}
+
+func runCrashd(o *option) error {
+	pwd, err := os.Getwd()
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err := os.Chdir(pwd); err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to go back to workdir: %v", err)
+		}
+	}()
+	if err := os.Chdir(o.baseDir); err != nil {
+		return err
+	}
+	logrus.SetOutput(os.Stdout)
+	if o.verbose {
+		logrus.SetLevel(logrus.DebugLevel)
+	}
+	return exec.Execute("velero-debug-collector", bytes.NewReader(scriptBytes), o.asCrashdArgMap())
+}
+
+func kubeconfigAndContext(fs *pflag.FlagSet) (string, string) {
+	pathOpt := clientcmd.NewDefaultPathOptions()
+	kubeconfig, _ := fs.GetString("kubeconfig")
+	if len(kubeconfig) > 0 {
+		pathOpt.LoadingRules.ExplicitPath = kubeconfig
+	}
+	kubecontext, _ := fs.GetString("kubecontext")
+	return pathOpt.GetDefaultFilename(), kubecontext
+}