cmd_gather_logs.go

package cli

import (
	"archive/zip"
	"bufio"
	"context"
	"errors"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"regexp"
	"strings"

	"github.com/spf13/cobra"
	"google.golang.org/grpc"

	"github.com/telepresenceio/telepresence/rpc/v2/connector"
	"github.com/telepresenceio/telepresence/v2/pkg/client"
	"github.com/telepresenceio/telepresence/v2/pkg/client/cli/ann"
	"github.com/telepresenceio/telepresence/v2/pkg/client/cli/util"
	"github.com/telepresenceio/telepresence/v2/pkg/client/scout"
	"github.com/telepresenceio/telepresence/v2/pkg/errcat"
	"github.com/telepresenceio/telepresence/v2/pkg/filelocation"
)

type gatherLogsArgs struct {
	outputFile     string
	daemons        string
	trafficAgents  string
	trafficManager bool
	anon           bool
	podYaml        bool
}

func gatherLogsCommand() *cobra.Command {
	gl := &gatherLogsArgs{}
	cmd := &cobra.Command{
		Use:   "gather-logs",
		Args:  cobra.NoArgs,
		Short: "Gather logs from traffic-manager, traffic-agent, user and root daemons, and export them into a zip file.",
		Long: `Gather logs from traffic-manager, traffic-agent, user and root daemons,
and export them into a zip file. Useful if you are opening a Github issue or asking
someone to help you debug Telepresence.`,
		Example: `Here are a few examples of how you can use this command:
# Get all logs and export to a given file
telepresence gather-logs -o /tmp/telepresence_logs.zip

# Get all logs and pod yaml manifests for components in the kubernetes cluster
telepresence gather-logs -o /tmp/telepresence_logs.zip --get-pod-yaml

# Get all logs for the daemons only
telepresence gather-logs --traffic-agents=None --traffic-manager=False

# Get all logs for pods that have "echo-easy" in the name, useful if you have multiple replicas
telepresence gather-logs --traffic-manager=False --traffic-agents=echo-easy

# Get all logs for a specific pod
telepresence gather-logs --traffic-manager=False --traffic-agents=echo-easy-6848967857-tw4jw

# Get logs from everything except the daemons
telepresence gather-logs --daemons=None
`,

		RunE: gl.gatherLogs,
		Annotations: map[string]string{
			ann.Session: ann.Optional,
		},
	}
	flags := cmd.Flags()
	flags.StringVarP(&gl.outputFile, "output-file", "o", "", "The file you want to output the logs to.")
	flags.StringVar(&gl.daemons, "daemons", "all", "The daemons you want logs from: all, root, user, None")
	flags.BoolVar(&gl.trafficManager, "traffic-manager", true, "If you want to collect logs from the traffic-manager")
	flags.StringVar(&gl.trafficAgents, "traffic-agents", "all", "Traffic-agents to collect logs from: all, name substring, None")
	flags.BoolVarP(&gl.anon, "anonymize", "a", false, "To anonymize pod names + namespaces from the logs")
	flags.BoolVarP(&gl.podYaml, "get-pod-yaml", "y", false, "Get the yaml of any pods you are getting logs for")
	return cmd
}

// anonymizer contains the mappings between things we want to anonymize
// and their new, anonymized name.  Using a map instead of simply redacting
// makes it easier for us to maintain certain relationships in the logs (e.g.
// namespaces things are in) which may be helpful in troubleshooting.
type anonymizer struct {
	namespaces map[string]string
	podNames   map[string]string
}

// gatherLogs gets the logs from the daemons (daemon + connector) and creates a zip.
func (gl *gatherLogsArgs) gatherLogs(cmd *cobra.Command, _ []string) error {
	if err := util.InitCommand(cmd); err != nil {
		return err
	}
	ctx := cmd.Context()
	scout := scout.NewReporter(ctx, "cli")
	scout.Start(ctx)
	defer scout.Close()

	// Get the log directory and return the error if we can't get it
	logDir, err := filelocation.AppUserLogDir(ctx)
	if err != nil {
		return errcat.User.New(err)
	}

	// If the user did not provide an outputFile, we'll use their current working directory
	if gl.outputFile == "" {
		pwd, err := os.Getwd()
		if err != nil {
			return errcat.User.New(err)
		}
		gl.outputFile = filepath.Join(pwd, "telepresence_logs.zip")
	} else if !strings.HasSuffix(gl.outputFile, ".zip") {
		return errcat.User.New("output file must end in .zip")
	}

	// Create a temporary directory where we will store the logs before we zip
	// them for export
	exportDir, err := os.MkdirTemp("", "logexp-")
	if err != nil {
		return errcat.User.New(err)
	}
	defer func() {
		if err := os.RemoveAll(exportDir); err != nil {
			fmt.Fprintf(cmd.ErrOrStderr(), "Failed to remove temp directory %s: %s", exportDir, err)
		}
	}()

	// First we add the daemonLogs to the export directory
	var daemonLogs []string
	switch gl.daemons {
	case "all":
		daemonLogs = append(daemonLogs, "cli", "connector", "daemon")
	case "root":
		daemonLogs = append(daemonLogs, "daemon")
	case "user":
		daemonLogs = append(daemonLogs, "connector")
	case "None":
	default:
		return errcat.User.New("Options for --daemons are: all, root, user, or None")
	}
	// Add metadata about the request, so we can track usage + see which
	// types of logs people are requesting more frequently.
	// This also gives us an idea about how much usage this command is
	// getting.
	scout.SetMetadatum(ctx, "daemon_logs", daemonLogs)
	scout.SetMetadatum(ctx, "traffic_manager_logs", gl.trafficManager)
	scout.SetMetadatum(ctx, "traffic_agent_logs", gl.trafficAgents)
	scout.SetMetadatum(ctx, "get_pod_yaml", gl.podYaml)
	scout.SetMetadatum(ctx, "anonymized_logs", gl.anon)
	scout.Report(ctx, "used_gather_logs")

	var az *anonymizer
	if gl.anon {
		az = &anonymizer{
			namespaces: make(map[string]string),
			podNames:   make(map[string]string),
		}
	}

	// Since getting the logs from k8s requires the connector, let's only do this
	// work if we know the user wants to get logs from k8s.
	// We gather those logs before we gather the connector.log so that problems that
	// may occur during that process will be included in the connector.log
	if gl.trafficManager || gl.trafficAgents != "None" {
		if err := gl.gatherClusterLogs(ctx, exportDir, az); err != nil {
			// We let the user know we were unable to get logs from the kubernetes components,
			// and why, but this shouldn't block the command returning successful with the logs
			// it was able to get.
			fmt.Fprintf(cmd.ErrOrStderr(), "error getting logs from kubernetes components: %s\n", err)
		}
	}

	// Get all logs from the logDir that match the daemons the user cares about.
	logFiles, err := os.ReadDir(logDir)
	if err != nil {
		return errcat.User.New(err)
	}
	for _, entry := range logFiles {
		if entry.IsDir() {
			continue
		}
		for _, logType := range daemonLogs {
			if strings.Contains(entry.Name(), logType) {
				srcFile := filepath.Join(logDir, entry.Name())

				// The cli.log is often empty, so this check is relevant.
				empty, err := isEmpty(srcFile)
				if err != nil {
					fmt.Fprintf(cmd.ErrOrStderr(), "failed stat on %s: %s\n", entry.Name(), err)
					continue
				}
				if empty {
					continue
				}
				dstFile := filepath.Join(exportDir, entry.Name())
				if err := copyFiles(dstFile, srcFile); err != nil {
					// We don't want to fail / exit abruptly if we can't copy certain
					// files, but we do want the user to know we were unsuccessful
					fmt.Fprintf(cmd.ErrOrStderr(), "failed exporting %s: %s\n", entry.Name(), err)
					continue
				}
			}
		}
	}

	// Zip up all the files we've created in the zip directory and return that to the user
	dirEntries, err := os.ReadDir(exportDir)
	files := make([]string, len(dirEntries))
	if err != nil {
		return errcat.User.New(err)
	}
	for i, entry := range dirEntries {
		if entry.IsDir() {
			files = files[:len(files)-1]
			continue
		}

		fullFileName := filepath.Join(exportDir, entry.Name())
		// anonymize the log if necessary
		if az != nil {
			if err := az.anonymizeLog(fullFileName); err != nil {
				fmt.Fprintf(cmd.ErrOrStderr(), "error anonymizing %s: %s\n", fullFileName, err)
			}
		}
		files[i] = fullFileName
	}

	if err := zipFiles(files, gl.outputFile); err != nil {
		return errcat.User.New(err)
	}

	fmt.Fprintf(cmd.OutOrStdout(), "Logs have been exported to %s\n", gl.outputFile)
	return nil
}

func (gl *gatherLogsArgs) gatherClusterLogs(ctx context.Context, exportDir string, az *anonymizer) error {
	// To get logs from the components in the kubernetes cluster, we ask the
	// traffic-manager.
	rq := &connector.LogsRequest{
		TrafficManager: gl.trafficManager,
		Agents:         gl.trafficAgents,
		GetPodYaml:     gl.podYaml,
		ExportDir:      exportDir,
	}
	userD := util.GetUserDaemon(ctx)
	if userD != nil {
		var opts []grpc.CallOption
		cfg := client.GetConfig(ctx)
		if !cfg.Grpc.MaxReceiveSize.IsZero() {
			if mz, ok := cfg.Grpc.MaxReceiveSize.AsInt64(); ok {
				opts = append(opts, grpc.MaxCallRecvMsgSize(int(mz)))
			}
		}
		lr, err := userD.GatherLogs(ctx, rq, opts...)
		if err != nil {
			return err
		}
		if az != nil {
			if err := az.anonymizeFileNames(lr, exportDir); err != nil {
				return err
			}
		}
	}
	return nil
}

func isEmpty(file string) (bool, error) {
	s, err := os.Stat(file)
	if err != nil {
		return false, err
	}
	return s.Size() == 0, err
}

// copyFiles copies files from one location into another.
func copyFiles(dstFile, srcFile string) error {
	srcWriter, err := os.Open(srcFile)
	if err != nil {
		return err
	}
	defer srcWriter.Close()

	dstWriter, err := os.Create(dstFile)
	if err != nil {
		return err
	}
	defer dstWriter.Close()

	if _, err := io.Copy(dstWriter, srcWriter); err != nil {
		return err
	}
	return nil
}

// zipFiles creates a zip file with the contents of all the files passed in.
// If some files do not exist, it will include that in the error message,
// but it will still create a zip file with as many files as it can.
func zipFiles(files []string, zipFileName string) error {
	zipFile, err := os.Create(zipFileName)
	if err != nil {
		return err
	}
	defer zipFile.Close()

	zipWriter := zip.NewWriter(zipFile)
	defer zipWriter.Close()

	addFileToZip := func(file string) error {
		fd, err := os.Open(file)
		if err != nil {
			return err
		}
		defer fd.Close()

		// Get the header information from the original file
		fileInfo, err := os.Stat(file)
		if err != nil {
			return err
		}
		fileHeader, err := zip.FileInfoHeader(fileInfo)
		if err != nil {
			return err
		}
		fileHeader.Method = zip.Deflate
		if err != nil {
			return err
		}

		// Get the basename of the file since that's all we want
		// to include in the zip
		baseName := filepath.Base(file)

		fileHeader.Name = baseName
		zfd, err := zipWriter.CreateHeader(fileHeader)
		if err != nil {
			return err
		}
		if _, err := io.Copy(zfd, fd); err != nil {
			return err
		}
		return nil
	}

	// Make a note of the files we fail to add to the zip so users know if the
	// zip is incomplete
	errMsg := ""
	for _, file := range files {
		// If the file doesn't have a name, then we obviously can't add it to
		// the zip. We have handling elsewhere to prevent files like this from
		// getting here but are extra cautious.
		if file == "" {
			continue
		}
		if err := addFileToZip(file); err != nil {
			errMsg += fmt.Sprintf("failed adding %s to zip file: %s ", file, err)
		}
	}
	if errMsg != "" {
		return errors.New(errMsg)
	}
	return nil
}

// anonymizeFileNames will anonymize the file names of all pods in the connector.LogResponse.
func (a *anonymizer) anonymizeFileNames(lr *connector.LogsResponse, exportDir string) error {
	for n, v := range lr.PodInfo {
		qn := filepath.Join(exportDir, n)
		if v != "ok" {
			// Write the error to retrieve the log as the log content. It's better than nothing
			_ = os.WriteFile(qn, []byte(v), 0o666)
		}
		anonQn := filepath.Join(exportDir, a.getPodName(n))
		if err := os.Rename(qn, anonQn); err != nil {
			return fmt.Errorf("failed to anonymize by renaming file name %s to %s", qn, anonQn)
		}
	}
	return nil
}

// getPodName returns an anonymized version of the podName. The anonymized value is cached so that
// the same anonymized name will be returned on subsequent calls using the same podName.
func (a *anonymizer) getPodName(podName string) string {
	// If this pod name has already been mapped, return that
	if anonName, ok := a.podNames[podName]; ok {
		return anonName
	}

	// the podName hasn't been anonymized yet so we split it up
	// so we can anonymize the namespace
	nameComponents := strings.SplitN(podName, ".", 2)
	if len(nameComponents) != 2 {
		// Note: the ordinal here is based on the total number of
		// pods, not the number of anonPods that are found. This
		// shouldn't be a problem because the main goal of this
		// is to make them distinct, but should we ever want the
		// ordinals to be strictly for anonPods, we'll need to
		// make a change here.
		unknownPodName := fmt.Sprintf("anonPod-%d.anonNamespace",
			len(a.podNames)+1)
		a.podNames[podName] = unknownPodName
		return unknownPodName
	}
	var anonPodName, anonNamespace string
	name, namespace := nameComponents[0], nameComponents[1]
	if val, ok := a.namespaces[namespace]; ok {
		anonNamespace = val
	} else {
		anonNamespace = fmt.Sprintf("namespace-%d", len(a.namespaces)+1)
		a.namespaces[namespace] = anonNamespace
	}

	// we want to special case the traffic-manager so we can easily distinguish
	// between that and the traffic-agents
	if strings.Contains(name, "traffic-manager") {
		anonPodName = fmt.Sprintf("traffic-manager.%s", anonNamespace)
	} else {
		anonPodName = fmt.Sprintf("pod-%d.%s", len(a.podNames)+1, anonNamespace)
	}
	// Store the anonPodName in the map
	a.podNames[podName] = anonPodName
	return anonPodName
}

// anonymizeLog is a helper function that replaces the namespace + podName
// used in the log with its anonymized version, provided by the anonymizer.
// It overwrites the file with the anonymized version.
func (a *anonymizer) anonymizeLog(logFile string) error {
	// Read the contents we are going to overwrite from the file
	content, err := os.ReadFile(logFile)
	if err != nil {
		return err
	}
	// Open the file with write so we can overwrite it
	stringContent := string(content)
	f, err := os.OpenFile(logFile, os.O_RDWR, 0)
	if err != nil {
		return err
	}
	defer f.Close()

	// First we replace the actual namespace with the anonymized
	// version.
	for namespace, anonNamespace := range a.namespaces {
		stringContent = strings.ReplaceAll(stringContent, namespace, anonNamespace)
	}
	// Now we do pod name which is a little bit more complicated
	for fullPodName, fullAnonPodName := range a.podNames {
		// strip the namespace off of the anonymized name
		anonPodParts := strings.Split(fullAnonPodName, ".")
		anonPodName := anonPodParts[0]

		// Strip the namespace off of the podName
		podParts := strings.Split(fullPodName, ".")

		for _, name := range getSignificantPodNames(podParts[0]) {
			stringContent = strings.ReplaceAll(stringContent, name, anonPodName)
		}
	}

	// Overwrite the file with the anonymized log
	err = f.Truncate(0)
	if err != nil {
		return err
	}
	_, err = f.Seek(0, 0)
	if err != nil {
		return err
	}
	fdWriter := bufio.NewWriter(f)
	_, err = fdWriter.WriteString(stringContent)
	if err != nil {
		return err
	}
	fdWriter.Flush()

	return nil
}

// getSignificantPodNames is a helper function that takes in a
// pod's name and returns the significant subnames that we want
// to anonymize.  It currently works for pods owned by StatefulSets,
// ReplicaSets, and Deployments.
func getSignificantPodNames(podName string) []string {
	// if the pods ends in an ordinal we can be pretty sure it's
	// coming from a StatefulSet.
	statefulSetRegex := regexp.MustCompile("(.*)-([0-9]+)$")
	// ReplicasSets, and therefore Deployments because they create
	// ReplicaSets, have a hash followed by a 5 character identity
	// string attached to the end.
	replicaSetRegex := regexp.MustCompile("(.*)-([0-9a-f]+)-([0-9a-z]{5})$")
	sigNames := []string{}
	switch {
	case statefulSetRegex.MatchString(podName):
		match := statefulSetRegex.FindStringSubmatch(podName)
		appName := match[1]
		// Add the pod name with and without the ordinal
		sigNames = append(sigNames, podName, appName)
	case replicaSetRegex.MatchString(podName):
		match := replicaSetRegex.FindStringSubmatch(podName)
		appName := match[1]
		rsName := fmt.Sprintf("%s-%s", appName, match[2])
		// add the app name with and without generated ReplicaSet hash
		sigNames = append(sigNames, podName, rsName, appName)
	default:
		// For default we don't do anything and will leave sigNames
		// as an empty slice
	}
	return sigNames
}