package libpod import ( "bufio" "context" "errors" "fmt" "io/ioutil" "os" "path/filepath" "strings" "time" "github.com/containers/podman/v4/libpod/define" "github.com/sirupsen/logrus" "golang.org/x/sys/unix" ) const ( // MaxHealthCheckNumberLogs is the maximum number of attempts we keep // in the healthcheck history file MaxHealthCheckNumberLogs int = 5 // MaxHealthCheckLogLength in characters MaxHealthCheckLogLength = 500 ) // HealthCheck verifies the state and validity of the healthcheck configuration // on the container and then executes the healthcheck func (r *Runtime) HealthCheck(name string) (define.HealthCheckStatus, error) { container, err := r.LookupContainer(name) if err != nil { return define.HealthCheckContainerNotFound, fmt.Errorf("unable to look up %s to perform a health check: %w", name, err) } hcStatus, err := checkHealthCheckCanBeRun(container) if err == nil { hcStatus, err := container.runHealthCheck() if err := container.processHealthCheckStatus(hcStatus); err != nil { return hcStatus, err } return hcStatus, err } return hcStatus, err } // runHealthCheck runs the health check as defined by the container func (c *Container) runHealthCheck() (define.HealthCheckStatus, error) { var ( newCommand []string returnCode int inStartPeriod bool ) hcCommand := c.HealthCheckConfig().Test if len(hcCommand) < 1 { return define.HealthCheckNotDefined, fmt.Errorf("container %s has no defined healthcheck", c.ID()) } switch hcCommand[0] { case "", define.HealthConfigTestNone: return define.HealthCheckNotDefined, fmt.Errorf("container %s has no defined healthcheck", c.ID()) case define.HealthConfigTestCmd: newCommand = hcCommand[1:] case define.HealthConfigTestCmdShell: // TODO: SHELL command from image not available in Container - use Docker default newCommand = []string{"/bin/sh", "-c", strings.Join(hcCommand[1:], " ")} default: // command supplied on command line - pass as-is newCommand = hcCommand } if len(newCommand) < 1 || newCommand[0] == "" { return define.HealthCheckNotDefined, fmt.Errorf("container %s has no defined healthcheck", c.ID()) } rPipe, wPipe, err := os.Pipe() if err != nil { return define.HealthCheckInternalError, fmt.Errorf("unable to create pipe for healthcheck session: %w", err) } defer wPipe.Close() defer rPipe.Close() streams := new(define.AttachStreams) streams.InputStream = bufio.NewReader(os.Stdin) streams.OutputStream = wPipe streams.ErrorStream = wPipe streams.AttachOutput = true streams.AttachError = true streams.AttachInput = true stdout := []string{} go func() { scanner := bufio.NewScanner(rPipe) for scanner.Scan() { stdout = append(stdout, scanner.Text()) } }() logrus.Debugf("executing health check command %s for %s", strings.Join(newCommand, " "), c.ID()) timeStart := time.Now() hcResult := define.HealthCheckSuccess config := new(ExecConfig) config.Command = newCommand exitCode, hcErr := c.exec(config, streams, nil, true) if hcErr != nil { hcResult = define.HealthCheckFailure if errors.Is(hcErr, define.ErrOCIRuntimeNotFound) || errors.Is(hcErr, define.ErrOCIRuntimePermissionDenied) || errors.Is(hcErr, define.ErrOCIRuntime) { returnCode = 1 hcErr = nil } else { returnCode = 125 } } else if exitCode != 0 { hcResult = define.HealthCheckFailure returnCode = 1 } timeEnd := time.Now() if c.HealthCheckConfig().StartPeriod > 0 { // there is a start-period we need to honor; we add startPeriod to container start time startPeriodTime := c.state.StartedTime.Add(c.HealthCheckConfig().StartPeriod) if timeStart.Before(startPeriodTime) { // we are still in the start period, flip the inStartPeriod bool inStartPeriod = true logrus.Debugf("healthcheck for %s being run in start-period", c.ID()) } } eventLog := strings.Join(stdout, "\n") if len(eventLog) > MaxHealthCheckLogLength { eventLog = eventLog[:MaxHealthCheckLogLength] } if timeEnd.Sub(timeStart) > c.HealthCheckConfig().Timeout { returnCode = -1 hcResult = define.HealthCheckFailure hcErr = fmt.Errorf("healthcheck command exceeded timeout of %s", c.HealthCheckConfig().Timeout.String()) } hcl := newHealthCheckLog(timeStart, timeEnd, returnCode, eventLog) if err := c.updateHealthCheckLog(hcl, inStartPeriod); err != nil { return hcResult, fmt.Errorf("unable to update health check log %s for %s: %w", c.healthCheckLogPath(), c.ID(), err) } return hcResult, hcErr } func (c *Container) processHealthCheckStatus(status define.HealthCheckStatus) error { if status == define.HealthCheckSuccess { return nil } switch c.config.HealthCheckOnFailureAction { case define.HealthCheckOnFailureActionNone: // Nothing to do case define.HealthCheckOnFailureActionKill: if err := c.Kill(uint(unix.SIGKILL)); err != nil { return fmt.Errorf("killing container health-check turned unhealthy: %w", err) } case define.HealthCheckOnFailureActionRestart: if err := c.RestartWithTimeout(context.Background(), c.config.StopTimeout); err != nil { return fmt.Errorf("restarting container after health-check turned unhealthy: %w", err) } case define.HealthCheckOnFailureActionStop: if err := c.Stop(); err != nil { return fmt.Errorf("stopping container after health-check turned unhealthy: %w", err) } default: // Should not happen but better be safe than sorry return fmt.Errorf("unsupported on-failure action %d", c.config.HealthCheckOnFailureAction) } return nil } func checkHealthCheckCanBeRun(c *Container) (define.HealthCheckStatus, error) { cstate, err := c.State() if err != nil { return define.HealthCheckInternalError, err } if cstate != define.ContainerStateRunning { return define.HealthCheckContainerStopped, fmt.Errorf("container %s is not running", c.ID()) } if !c.HasHealthCheck() { return define.HealthCheckNotDefined, fmt.Errorf("container %s has no defined healthcheck", c.ID()) } return define.HealthCheckDefined, nil } func newHealthCheckLog(start, end time.Time, exitCode int, log string) define.HealthCheckLog { return define.HealthCheckLog{ Start: start.Format(time.RFC3339Nano), End: end.Format(time.RFC3339Nano), ExitCode: exitCode, Output: log, } } // updatedHealthCheckStatus updates the health status of the container // in the healthcheck log func (c *Container) updateHealthStatus(status string) error { healthCheck, err := c.getHealthCheckLog() if err != nil { return err } healthCheck.Status = status newResults, err := json.Marshal(healthCheck) if err != nil { return fmt.Errorf("unable to marshall healthchecks for writing status: %w", err) } return ioutil.WriteFile(c.healthCheckLogPath(), newResults, 0700) } // UpdateHealthCheckLog parses the health check results and writes the log func (c *Container) updateHealthCheckLog(hcl define.HealthCheckLog, inStartPeriod bool) error { healthCheck, err := c.getHealthCheckLog() if err != nil { return err } if hcl.ExitCode == 0 { // set status to healthy, reset failing state to 0 healthCheck.Status = define.HealthCheckHealthy healthCheck.FailingStreak = 0 } else { if len(healthCheck.Status) < 1 { healthCheck.Status = define.HealthCheckHealthy } if !inStartPeriod { // increment failing streak healthCheck.FailingStreak++ // if failing streak > retries, then status to unhealthy if healthCheck.FailingStreak >= c.HealthCheckConfig().Retries { healthCheck.Status = define.HealthCheckUnhealthy } } } healthCheck.Log = append(healthCheck.Log, hcl) if len(healthCheck.Log) > MaxHealthCheckNumberLogs { healthCheck.Log = healthCheck.Log[1:] } newResults, err := json.Marshal(healthCheck) if err != nil { return fmt.Errorf("unable to marshall healthchecks for writing: %w", err) } return ioutil.WriteFile(c.healthCheckLogPath(), newResults, 0700) } // HealthCheckLogPath returns the path for where the health check log is func (c *Container) healthCheckLogPath() string { return filepath.Join(filepath.Dir(c.state.RunDir), "healthcheck.log") } // getHealthCheckLog returns HealthCheck results by reading the container's // health check log file. If the health check log file does not exist, then // an empty healthcheck struct is returned // The caller should lock the container before this function is called. func (c *Container) getHealthCheckLog() (define.HealthCheckResults, error) { var healthCheck define.HealthCheckResults if _, err := os.Stat(c.healthCheckLogPath()); os.IsNotExist(err) { return healthCheck, nil } b, err := ioutil.ReadFile(c.healthCheckLogPath()) if err != nil { return healthCheck, fmt.Errorf("failed to read health check log file: %w", err) } if err := json.Unmarshal(b, &healthCheck); err != nil { return healthCheck, fmt.Errorf("failed to unmarshal existing healthcheck results in %s: %w", c.healthCheckLogPath(), err) } return healthCheck, nil } // HealthCheckStatus returns the current state of a container with a healthcheck func (c *Container) HealthCheckStatus() (string, error) { c.lock.Lock() defer c.lock.Unlock() return c.healthCheckStatus() } // Internal function to return the current state of a container with a healthcheck. // This function does not lock the container. func (c *Container) healthCheckStatus() (string, error) { if !c.HasHealthCheck() { return "", fmt.Errorf("container %s has no defined healthcheck", c.ID()) } if err := c.syncContainer(); err != nil { return "", err } results, err := c.getHealthCheckLog() if err != nil { return "", fmt.Errorf("unable to get healthcheck log for %s: %w", c.ID(), err) } return results.Status, nil } func (c *Container) disableHealthCheckSystemd() bool { if os.Getenv("DISABLE_HC_SYSTEMD") == "true" { return true } if c.config.HealthCheckConfig.Interval == 0 { return true } return false }