Merge pull request #2562 from baude/healtcheckphase2

healthcheck phase 2

1 files changed, 119 insertions, 10 deletions

diff --git a/libpod/healthcheck.go b/libpod/healthcheck.go
index 81addb9a8..d2c0ea0fb 100644
--- a/libpod/healthcheck.go
+++ b/libpod/healthcheck.go
@@ -1,9 +1,15 @@
 package libpod
 
 import (
+	"bufio"
+	"bytes"
+	"io/ioutil"
 	"os"
+	"path/filepath"
 	"strings"
+	"time"
 
+	"github.com/containers/libpod/pkg/inspect"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
@@ -30,8 +36,29 @@ const (
 	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 healtcheck 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"
 )
 
+// 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) {
@@ -48,33 +75,51 @@ func (r *Runtime) HealthCheck(name string) (HealthCheckStatus, error) {
 
 // RunHealthCheck runs the health check as defined by the container
 func (c *Container) RunHealthCheck() (HealthCheckStatus, error) {
-	var newCommand []string
+	var (
+		newCommand []string
+		returnCode int
+		capture    bytes.Buffer
+	)
 	hcStatus, err := checkHealthCheckCanBeRun(c)
 	if err != nil {
 		return hcStatus, err
 	}
 	hcCommand := c.HealthCheckConfig().Test
 	if len(hcCommand) > 0 && hcCommand[0] == "CMD-SHELL" {
-		newCommand = []string{"sh", "-c"}
-		newCommand = append(newCommand, hcCommand[1:]...)
+		newCommand = []string{"sh", "-c", strings.Join(hcCommand[1:], " ")}
 	} else {
 		newCommand = hcCommand
 	}
-	// TODO when history/logging is implemented for healthcheck, we need to change the output streams
-	// so we can capture i/o
+	captureBuffer := bufio.NewWriter(&capture)
+	hcw := hcWriteCloser{
+		captureBuffer,
+	}
 	streams := new(AttachStreams)
-	streams.OutputStream = os.Stdout
-	streams.ErrorStream = os.Stderr
+	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())
-	if err := c.Exec(false, false, []string{}, newCommand, "", "", streams, 0); err != nil {
-		return HealthCheckFailure, err
+	timeStart := time.Now()
+	hcResult := HealthCheckSuccess
+	hcErr := c.Exec(false, false, []string{}, newCommand, "", "", streams, 0)
+	if hcErr != nil {
+		hcResult = HealthCheckFailure
+		returnCode = 1
+	}
+	timeEnd := time.Now()
+	eventLog := capture.String()
+	if len(eventLog) > MaxHealthCheckLogLength {
+		eventLog = eventLog[:MaxHealthCheckLogLength]
 	}
-	return HealthCheckSuccess, nil
+	hcl := newHealthCheckLog(timeStart, timeEnd, returnCode, eventLog)
+	if err := c.updateHealthCheckLog(hcl); 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) {
@@ -90,3 +135,67 @@ func checkHealthCheckCanBeRun(c *Container) (HealthCheckStatus, error) {
 	}
 	return HealthCheckDefined, nil
 }
+
+func newHealthCheckLog(start, end time.Time, exitCode int, log string) inspect.HealthCheckLog {
+	return inspect.HealthCheckLog{
+		Start:    start.Format(time.RFC3339Nano),
+		End:      end.Format(time.RFC3339Nano),
+		ExitCode: exitCode,
+		Output:   log,
+	}
+}
+
+// UpdateHealthCheckLog parses the health check results and writes the log
+func (c *Container) updateHealthCheckLog(hcl inspect.HealthCheckLog) 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
+		}
+		// 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() (inspect.HealthCheckResults, error) {
+	var healthCheck inspect.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
+}