package debug import ( "archive/tar" "bufio" "compress/gzip" "context" "encoding/json" "errors" "flag" "fmt" "io" "os" "os/signal" "path/filepath" "strings" "syscall" "time" "github.com/hashicorp/go-multierror" "github.com/mitchellh/cli" "golang.org/x/sync/errgroup" "github.com/hashicorp/consul/api" "github.com/hashicorp/consul/command/flags" ) const ( // debugInterval is the interval in which to capture dynamic information // when running debug debugInterval = 30 * time.Second // debugDuration is the total duration that debug runs before being // shut down debugDuration = 2 * time.Minute // debugDurationGrace is a period of time added to the specified // duration to allow intervals to capture within that time debugDurationGrace = 2 * time.Second // debugMinInterval is the minimum a user can configure the interval // to prevent accidental DOS debugMinInterval = 5 * time.Second // debugMinDuration is the minimum a user can configure the duration // to ensure that all information can be collected in time debugMinDuration = 10 * time.Second // debugArchiveExtension is the extension for archive files debugArchiveExtension = ".tar.gz" // debugProtocolVersion is the version of the package that is // generated. If this format changes interface, this version // can be incremented so clients can selectively support packages debugProtocolVersion = 1 ) func New(ui cli.Ui) *cmd { ui = &cli.PrefixedUi{ OutputPrefix: "==> ", InfoPrefix: " ", ErrorPrefix: "==> ", Ui: ui, } c := &cmd{UI: ui} c.init() return c } type cmd struct { UI cli.Ui flags *flag.FlagSet http *flags.HTTPFlags help string // flags interval time.Duration duration time.Duration output string archive bool capture []string client *api.Client // validateTiming can be used to skip validation of interval, duration. This // is primarily useful for testing validateTiming bool // timeNow is a shim for testing, it is used to generate the time used in // file paths. timeNow func() time.Time } // debugIndex is used to manage the summary of all data recorded // during the debug, to be written to json at the end of the run // and stored at the root. Each attribute corresponds to a file or files. type debugIndex struct { // Version of the debug package Version int // Version of the target Consul agent AgentVersion string Interval string Duration string Targets []string } // timeDateformat is a modified version of time.RFC3339 which replaces colons with // hyphens. This is to make it more convenient to untar these files, because // tar assumes colons indicate the file is on a remote host, unless --force-local // is used. const timeDateFormat = "2006-01-02T15-04-05Z0700" func (c *cmd) init() { c.flags = flag.NewFlagSet("", flag.ContinueOnError) defaultFilename := fmt.Sprintf("consul-debug-%v", time.Now().Format(timeDateFormat)) c.flags.Var((*flags.AppendSliceValue)(&c.capture), "capture", fmt.Sprintf("One or more types of information to capture. This can be used "+ "to capture a subset of information, and defaults to capturing "+ "everything available. Possible information for capture: %s. "+ "This can be repeated multiple times.", strings.Join(defaultTargets, ", "))) c.flags.DurationVar(&c.interval, "interval", debugInterval, fmt.Sprintf("The interval in which to capture dynamic information such as "+ "telemetry, and profiling. Defaults to %s.", debugInterval)) c.flags.DurationVar(&c.duration, "duration", debugDuration, fmt.Sprintf("The total time to record information. "+ "Defaults to %s.", debugDuration)) c.flags.BoolVar(&c.archive, "archive", true, "Boolean value for if the files "+ "should be archived and compressed. Setting this to false will skip the "+ "archive step and leave the directory of information on the current path.") c.flags.StringVar(&c.output, "output", defaultFilename, "The path "+ "to the compressed archive that will be created with the "+ "information after collection.") c.http = &flags.HTTPFlags{} flags.Merge(c.flags, c.http.ClientFlags()) c.help = flags.Usage(help, c.flags) c.validateTiming = true c.timeNow = func() time.Time { return time.Now().UTC() } } func (c *cmd) Run(args []string) int { ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM) defer cancel() if err := c.flags.Parse(args); err != nil { c.UI.Error(fmt.Sprintf("Error parsing flags: %s", err)) return 1 } if len(c.flags.Args()) > 0 { c.UI.Error("debug: Too many arguments provided, expected 0") return 1 } // Connect to the agent client, err := c.http.APIClient() if err != nil { c.UI.Error(fmt.Sprintf("Error connecting to Consul agent: %s", err)) return 1 } c.client = client version, err := c.prepare() if err != nil { c.UI.Error(fmt.Sprintf("Capture validation failed: %v", err)) return 1 } archiveName := c.output // Show the user the final file path if archiving if c.archive { archiveName = archiveName + debugArchiveExtension } c.UI.Output("Starting debugger and capturing static information...") // Output metadata about target agent c.UI.Info(fmt.Sprintf(" Agent Version: '%s'", version)) c.UI.Info(fmt.Sprintf(" Interval: '%s'", c.interval)) c.UI.Info(fmt.Sprintf(" Duration: '%s'", c.duration)) c.UI.Info(fmt.Sprintf(" Output: '%s'", archiveName)) c.UI.Info(fmt.Sprintf(" Capture: '%s'", strings.Join(c.capture, ", "))) // Add the extra grace period to ensure // all intervals will be captured within the time allotted c.duration = c.duration + debugDurationGrace // Capture static information from the target agent err = c.captureStatic() if err != nil { c.UI.Warn(fmt.Sprintf("Static capture failed: %v", err)) } // Capture dynamic information from the target agent, blocking for duration if c.captureTarget(targetMetrics) || c.captureTarget(targetLogs) || c.captureTarget(targetProfiles) { g := new(errgroup.Group) g.Go(func() error { return c.captureInterval(ctx) }) g.Go(func() error { return c.captureLongRunning(ctx) }) err = g.Wait() if err != nil { c.UI.Error(fmt.Sprintf("Error encountered during collection: %v", err)) } } // Record some information for the index at the root of the archive index := &debugIndex{ Version: debugProtocolVersion, AgentVersion: version, Interval: c.interval.String(), Duration: c.duration.String(), Targets: c.capture, } if err := writeJSONFile(filepath.Join(c.output, "index.json"), index); err != nil { c.UI.Error(fmt.Sprintf("Error creating index document: %v", err)) return 1 } // Archive the data if configured to if c.archive { err = c.createArchive() if err != nil { c.UI.Warn(fmt.Sprintf("Archive creation failed: %v", err)) return 1 } } c.UI.Info(fmt.Sprintf("Saved debug archive: %s", archiveName)) return 0 } // prepare validates agent settings against targets and prepares the environment for capturing func (c *cmd) prepare() (version string, err error) { // Ensure realistic duration and intervals exists if c.validateTiming { if c.duration < debugMinDuration { return "", fmt.Errorf("duration must be longer than %s", debugMinDuration) } if c.interval < debugMinInterval { return "", fmt.Errorf("interval must be longer than %s", debugMinDuration) } if c.duration < c.interval { return "", fmt.Errorf("duration (%s) must be longer than interval (%s)", c.duration, c.interval) } } // Retrieve and process agent information necessary to validate self, err := c.client.Agent().Self() if err != nil { return "", fmt.Errorf("error querying target agent: %s. verify connectivity and agent address", err) } version, ok := self["Config"]["Version"].(string) if !ok { return "", fmt.Errorf("agent response did not contain version key") } // If none are specified we will collect information from // all by default if len(c.capture) == 0 { c.capture = defaultTargets } // If EnableDebug is not true, skip collecting pprof enableDebug, ok := self["DebugConfig"]["EnableDebug"].(bool) if !ok { return "", fmt.Errorf("agent response did not contain EnableDebug key") } if !enableDebug { cs := c.capture for i := 0; i < len(cs); i++ { if cs[i] == "pprof" { c.capture = append(cs[:i], cs[i+1:]...) i-- c.UI.Warn("[WARN] Unable to capture pprof. Set enable_debug to true on target agent to enable profiling.") } } } for _, t := range c.capture { if !allowedTarget(t) { return version, fmt.Errorf("target not found: %s", t) } } if _, err := os.Stat(c.output); os.IsNotExist(err) { err := os.MkdirAll(c.output, 0755) if err != nil { return version, fmt.Errorf("could not create output directory: %s", err) } } else { return version, fmt.Errorf("output directory already exists: %s", c.output) } return version, nil } // captureStatic captures static target information and writes it // to the output path func (c *cmd) captureStatic() error { var errs error if c.captureTarget(targetHost) { host, err := c.client.Agent().Host() if err != nil { errs = multierror.Append(errs, err) } if err := writeJSONFile(filepath.Join(c.output, targetHost+".json"), host); err != nil { errs = multierror.Append(errs, err) } } if c.captureTarget(targetAgent) { agent, err := c.client.Agent().Self() if err != nil { errs = multierror.Append(errs, err) } if err := writeJSONFile(filepath.Join(c.output, targetAgent+".json"), agent); err != nil { errs = multierror.Append(errs, err) } } if c.captureTarget(targetMembers) { members, err := c.client.Agent().Members(true) if err != nil { errs = multierror.Append(errs, err) } if err := writeJSONFile(filepath.Join(c.output, targetMembers+".json"), members); err != nil { errs = multierror.Append(errs, err) } } return errs } func writeJSONFile(filename string, content interface{}) error { marshaled, err := json.MarshalIndent(content, "", "\t") if err != nil { return err } return os.WriteFile(filename, marshaled, 0644) } // captureInterval blocks for the duration of the command // specified by the duration flag, capturing the dynamic // targets at the interval specified func (c *cmd) captureInterval(ctx context.Context) error { intervalChn := time.NewTicker(c.interval) defer intervalChn.Stop() durationChn := time.After(c.duration) intervalCount := 0 c.UI.Output(fmt.Sprintf("Beginning capture interval %s (%d)", time.Now().UTC(), intervalCount)) err := captureShortLived(c) if err != nil { return err } c.UI.Output(fmt.Sprintf("Capture successful %s (%d)", time.Now().UTC(), intervalCount)) for { select { case t := <-intervalChn.C: intervalCount++ err := captureShortLived(c) if err != nil { return err } c.UI.Output(fmt.Sprintf("Capture successful %s (%d)", t.UTC(), intervalCount)) case <-durationChn: intervalChn.Stop() return nil case <-ctx.Done(): return errors.New("stopping collection due to shutdown signal") } } } func captureShortLived(c *cmd) error { g := new(errgroup.Group) if c.captureTarget(targetProfiles) { dir, err := makeIntervalDir(c.output, c.timeNow()) if err != nil { return err } g.Go(func() error { return c.captureHeap(dir) }) g.Go(func() error { return c.captureGoRoutines(dir) }) } return g.Wait() } func makeIntervalDir(base string, now time.Time) (string, error) { dir := filepath.Join(base, now.Format(timeDateFormat)) if err := os.MkdirAll(dir, 0755); err != nil { return "", fmt.Errorf("failed to create output directory %v: %w", dir, err) } return dir, nil } func (c *cmd) captureLongRunning(ctx context.Context) error { g := new(errgroup.Group) if c.captureTarget(targetProfiles) { g.Go(func() error { // use ctx without a timeout to allow the profile to finish sending return c.captureProfile(ctx, c.duration.Seconds()) }) g.Go(func() error { // use ctx without a timeout to allow the trace to finish sending return c.captureTrace(ctx, int(c.interval.Seconds())) }) } if c.captureTarget(targetLogs) { g.Go(func() error { ctx, cancel := context.WithTimeout(ctx, c.duration) defer cancel() return c.captureLogs(ctx) }) } if c.captureTarget(targetMetrics) { g.Go(func() error { ctx, cancel := context.WithTimeout(ctx, c.duration) defer cancel() return c.captureMetrics(ctx) }) } return g.Wait() } func (c *cmd) captureGoRoutines(outputDir string) error { gr, err := c.client.Debug().Goroutine() if err != nil { return fmt.Errorf("failed to collect goroutine profile: %w", err) } return os.WriteFile(filepath.Join(outputDir, "goroutine.prof"), gr, 0644) } func (c *cmd) captureTrace(ctx context.Context, duration int) error { prof, err := c.client.Debug().PProf(ctx, "trace", duration) if err != nil { return fmt.Errorf("failed to collect cpu profile: %w", err) } defer prof.Close() r := bufio.NewReader(prof) fh, err := os.Create(filepath.Join(c.output, "trace.out")) if err != nil { return err } defer fh.Close() _, err = r.WriteTo(fh) return err } func (c *cmd) captureProfile(ctx context.Context, s float64) error { prof, err := c.client.Debug().PProf(ctx, "profile", int(s)) if err != nil { return fmt.Errorf("failed to collect cpu profile: %w", err) } defer prof.Close() r := bufio.NewReader(prof) fh, err := os.Create(filepath.Join(c.output, "profile.prof")) if err != nil { return err } defer fh.Close() _, err = r.WriteTo(fh) return err } func (c *cmd) captureHeap(outputDir string) error { heap, err := c.client.Debug().Heap() if err != nil { return fmt.Errorf("failed to collect heap profile: %w", err) } return os.WriteFile(filepath.Join(outputDir, "heap.prof"), heap, 0644) } func (c *cmd) captureLogs(ctx context.Context) error { logCh, err := c.client.Agent().Monitor("DEBUG", ctx.Done(), nil) if err != nil { return err } // Create the log file for writing f, err := os.Create(filepath.Join(c.output, "consul.log")) if err != nil { return err } defer f.Close() for { select { case log := <-logCh: if log == "" { return nil } if _, err = f.WriteString(log + "\n"); err != nil { return err } case <-ctx.Done(): return nil } } } func (c *cmd) captureMetrics(ctx context.Context) error { stream, err := c.client.Agent().MetricsStream(ctx) if err != nil { return err } defer stream.Close() fh, err := os.Create(filepath.Join(c.output, "metrics.json")) if err != nil { return fmt.Errorf("failed to create metrics file: %w", err) } defer fh.Close() b := bufio.NewReader(stream) _, err = b.WriteTo(fh) if err != nil && !errors.Is(err, context.DeadlineExceeded) { return fmt.Errorf("failed to copy metrics to file: %w", err) } return nil } // allowedTarget returns true if the target is a recognized name of a capture // target. func allowedTarget(target string) bool { for _, dt := range defaultTargets { if dt == target { return true } } for _, t := range deprecatedTargets { if t == target { return true } } return false } // captureTarget returns true if the target capture type is enabled. func (c *cmd) captureTarget(target string) bool { for _, dt := range c.capture { if dt == target { return true } if target == targetMembers && dt == targetCluster { return true } } return false } // createArchive walks the files in the temporary directory // and creates a tar file that is gzipped with the contents func (c *cmd) createArchive() error { path := c.output + debugArchiveExtension tempName, err := c.createArchiveTemp(path) if err != nil { return err } if err := os.Rename(tempName, path); err != nil { return err } // fsync the dir to make the rename stick if err := syncParentDir(path); err != nil { return err } // Remove directory that has been archived if err := os.RemoveAll(c.output); err != nil { return fmt.Errorf("failed to remove archived directory: %s", err) } return nil } func syncParentDir(name string) error { f, err := os.Open(filepath.Dir(name)) if err != nil { return err } defer f.Close() return f.Sync() } func (c *cmd) createArchiveTemp(path string) (tempName string, err error) { dir := filepath.Dir(path) name := filepath.Base(path) f, err := os.CreateTemp(dir, name+".tmp") if err != nil { return "", fmt.Errorf("failed to create compressed temp archive: %s", err) } g := gzip.NewWriter(f) t := tar.NewWriter(g) tempName = f.Name() cleanup := func(err error) (string, error) { _ = t.Close() _ = g.Close() _ = f.Close() _ = os.Remove(tempName) return "", err } err = filepath.Walk(c.output, func(file string, fi os.FileInfo, err error) error { if err != nil { return fmt.Errorf("failed to walk filepath for archive: %s", err) } header, err := tar.FileInfoHeader(fi, fi.Name()) if err != nil { return fmt.Errorf("failed to create compressed archive header: %s", err) } header.Name = filepath.Join(filepath.Base(c.output), strings.TrimPrefix(file, c.output)) if err := t.WriteHeader(header); err != nil { return fmt.Errorf("failed to write compressed archive header: %s", err) } // Only copy files if !fi.Mode().IsRegular() { return nil } f, err := os.Open(file) if err != nil { return fmt.Errorf("failed to open target files for archive: %s", err) } if _, err := io.Copy(t, f); err != nil { return fmt.Errorf("failed to copy files for archive: %s", err) } return f.Close() }) if err != nil { return cleanup(fmt.Errorf("failed to walk output path for archive: %s", err)) } // Explicitly close things in the correct order (tar then gzip) so we // know if they worked. if err := t.Close(); err != nil { return cleanup(err) } if err := g.Close(); err != nil { return cleanup(err) } // Guarantee that the contents of the temp file are flushed to disk. if err := f.Sync(); err != nil { return cleanup(err) } // Close the temp file and go back to the wrapper function for the rest. if err := f.Close(); err != nil { return cleanup(err) } return tempName, nil } const ( targetMetrics = "metrics" targetLogs = "logs" targetProfiles = "pprof" targetHost = "host" targetAgent = "agent" targetMembers = "members" // targetCluster is the now deprecated name for targetMembers targetCluster = "cluster" ) // defaultTargets specifies the list of targets that will be captured by default var defaultTargets = []string{ targetMetrics, targetLogs, targetProfiles, targetHost, targetAgent, targetMembers, } var deprecatedTargets = []string{targetCluster} func (c *cmd) Synopsis() string { return "Records a debugging archive for operators" } func (c *cmd) Help() string { return c.help } const help = ` Usage: consul debug [options] Monitors a Consul agent for the specified period of time, recording information about the agent, cluster, and environment to an archive written to the specified path. If ACLs are enabled, an 'operator:read' token must be supplied in order to perform this operation. To create a debug archive in the current directory for the default duration and interval, capturing all information available: $ consul debug The command stores captured data at the configured output path through the duration, and will archive the data at the same path if interrupted. Flags can be used to customize the duration and interval of the operation. Duration is the total time to capture data for from the target agent and interval controls how often dynamic data such as metrics are scraped. $ consul debug -interval=20s -duration=1m The capture flag can be specified multiple times to limit information retrieved. $ consul debug -capture metrics -capture agent By default, the archive containing the debugging information is saved to the current directory as a .tar.gz file. The output path can be specified, as well as an option to disable archiving, leaving the directory intact. $ consul debug -output=/foo/bar/my-debugging -archive=false Note: Information collected by this command has the potential to be highly sensitive. Sensitive material such as ACL tokens and other commonly secret material are redacted automatically, but we strongly recommend review of the data within the archive prior to transmitting it. For a full list of options and examples, please see the Consul documentation. `