package libpod import ( "bufio" "bytes" "io/ioutil" "os" "path/filepath" "strings" "time" "github.com/containers/libpod/libpod/define" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) // HealthCheckStatus represents the current state of a container type HealthCheckStatus int const ( // HealthCheckSuccess means the health worked HealthCheckSuccess HealthCheckStatus = iota // HealthCheckFailure means the health ran and failed HealthCheckFailure HealthCheckStatus = iota // HealthCheckContainerStopped means the health check cannot // be run because the container is stopped HealthCheckContainerStopped HealthCheckStatus = iota // HealthCheckContainerNotFound means the container could // not be found in local store HealthCheckContainerNotFound HealthCheckStatus = iota // HealthCheckNotDefined means the container has no health // check defined in it HealthCheckNotDefined HealthCheckStatus = iota // HealthCheckInternalError means somes something failed obtaining or running // a given health check HealthCheckInternalError HealthCheckStatus = iota // HealthCheckDefined means the healthcheck was found on the container HealthCheckDefined HealthCheckStatus = iota // MaxHealthCheckNumberLogs is the maximum number of attempts we keep // in the healthcheck history file MaxHealthCheckNumberLogs int = 5 // MaxHealthCheckLogLength in characters MaxHealthCheckLogLength = 500 // HealthCheckHealthy describes a healthy container HealthCheckHealthy string = "healthy" // HealthCheckUnhealthy describes an unhealthy container HealthCheckUnhealthy string = "unhealthy" // HealthCheckStarting describes the time between when the container starts // and the start-period (time allowed for the container to start and application // to be running) expires. HealthCheckStarting string = "starting" ) // HealthCheckResults describes the results/logs from a healthcheck type HealthCheckResults struct { // Status healthy or unhealthy Status string `json:"Status"` // FailingStreak is the number of consecutive failed healthchecks FailingStreak int `json:"FailingStreak"` // Log describes healthcheck attempts and results Log []HealthCheckLog `json:"Log"` } // HealthCheckLog describes the results of a single healthcheck type HealthCheckLog struct { // Start time as string Start string `json:"Start"` // End time as a string End string `json:"End"` // Exitcode is 0 or 1 ExitCode int `json:"ExitCode"` // Output is the stdout/stderr from the healthcheck command Output string `json:"Output"` } // hcWriteCloser allows us to use bufio as a WriteCloser type hcWriteCloser struct { *bufio.Writer } // Used to add a closer to bufio func (hcwc hcWriteCloser) Close() error { return nil } // HealthCheck verifies the state and validity of the healthcheck configuration // on the container and then executes the healthcheck func (r *Runtime) HealthCheck(name string) (HealthCheckStatus, error) { container, err := r.LookupContainer(name) if err != nil { return HealthCheckContainerNotFound, errors.Wrapf(err, "unable to lookup %s to perform a health check", name) } hcStatus, err := checkHealthCheckCanBeRun(container) if err == nil { return container.runHealthCheck() } return hcStatus, err } // runHealthCheck runs the health check as defined by the container func (c *Container) runHealthCheck() (HealthCheckStatus, error) { var ( newCommand []string returnCode int capture bytes.Buffer inStartPeriod bool ) hcCommand := c.HealthCheckConfig().Test if len(hcCommand) < 1 { return HealthCheckNotDefined, errors.Errorf("container %s has no defined healthcheck", c.ID()) } switch hcCommand[0] { case "", "NONE": return HealthCheckNotDefined, errors.Errorf("container %s has no defined healthcheck", c.ID()) case "CMD": newCommand = hcCommand[1:] case "CMD-SHELL": // 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 HealthCheckNotDefined, errors.Errorf("container %s has no defined healthcheck", c.ID()) } captureBuffer := bufio.NewWriter(&capture) hcw := hcWriteCloser{ captureBuffer, } streams := new(AttachStreams) streams.OutputStream = hcw streams.ErrorStream = hcw streams.InputStream = os.Stdin streams.AttachOutput = true streams.AttachError = true streams.AttachInput = true logrus.Debugf("executing health check command %s for %s", strings.Join(newCommand, " "), c.ID()) timeStart := time.Now() hcResult := HealthCheckSuccess hcErr := c.Exec(false, false, []string{}, newCommand, "", "", streams, 0) if hcErr != nil { hcResult = 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 := capture.String() if len(eventLog) > MaxHealthCheckLogLength { eventLog = eventLog[:MaxHealthCheckLogLength] } if timeEnd.Sub(timeStart) > c.HealthCheckConfig().Timeout { returnCode = -1 hcResult = HealthCheckFailure hcErr = errors.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, errors.Wrapf(err, "unable to update health check log %s for %s", c.healthCheckLogPath(), c.ID()) } return hcResult, hcErr } func checkHealthCheckCanBeRun(c *Container) (HealthCheckStatus, error) { cstate, err := c.State() if err != nil { return HealthCheckInternalError, err } if cstate != define.ContainerStateRunning { return HealthCheckContainerStopped, errors.Errorf("container %s is not running", c.ID()) } if !c.HasHealthCheck() { return HealthCheckNotDefined, errors.Errorf("container %s has no defined healthcheck", c.ID()) } return HealthCheckDefined, nil } func newHealthCheckLog(start, end time.Time, exitCode int, log string) HealthCheckLog { return 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 errors.Wrapf(err, "unable to marshall healthchecks for writing status") } return ioutil.WriteFile(c.healthCheckLogPath(), newResults, 0700) } // UpdateHealthCheckLog parses the health check results and writes the log func (c *Container) updateHealthCheckLog(hcl 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 = HealthCheckHealthy healthCheck.FailingStreak = 0 } else { if len(healthCheck.Status) < 1 { healthCheck.Status = HealthCheckHealthy } if !inStartPeriod { // increment failing streak healthCheck.FailingStreak = healthCheck.FailingStreak + 1 // if failing streak > retries, then status to unhealthy if int(healthCheck.FailingStreak) >= c.HealthCheckConfig().Retries { healthCheck.Status = 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 errors.Wrapf(err, "unable to marshall healthchecks for writing") } 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.LogPath()), "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 func (c *Container) GetHealthCheckLog() (HealthCheckResults, error) { var healthCheck HealthCheckResults if _, err := os.Stat(c.healthCheckLogPath()); os.IsNotExist(err) { return healthCheck, nil } b, err := ioutil.ReadFile(c.healthCheckLogPath()) if err != nil { return healthCheck, errors.Wrapf(err, "failed to read health check log file %s", c.healthCheckLogPath()) } if err := json.Unmarshal(b, &healthCheck); err != nil { return healthCheck, errors.Wrapf(err, "failed to unmarshal existing healthcheck results in %s", c.healthCheckLogPath()) } return healthCheck, nil } // HealthCheckStatus returns the current state of a container with a healthcheck func (c *Container) HealthCheckStatus() (string, error) { if !c.HasHealthCheck() { return "", errors.Errorf("container %s has no defined healthcheck", c.ID()) } results, err := c.GetHealthCheckLog() if err != nil { return "", errors.Wrapf(err, "unable to get healthcheck log for %s", c.ID()) } 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 }