Save failed healthchecks, and put path in $TEXT_FILENAME

To allow scripts to access them.

monitor/daemon.go

@@ -16,6 +16,7 @@ import (
 	"golang.org/x/sync/errgroup"
 	"log"
 	insecurerand "math/rand"
+	"path/filepath"
 	"software.sslmate.com/src/certspotter/loglist"
 	"time"
 )
@@ -50,12 +51,18 @@ type daemon struct {
 
 func (daemon *daemon) healthCheck(ctx context.Context) error {
 	if time.Since(daemon.logsLoadedAt) >= daemon.config.HealthCheckInterval {
-		if err := notify(ctx, daemon.config, &staleLogListEvent{
+		textPath := filepath.Join(daemon.config.StateDir, "healthchecks", healthCheckFilename())
+		event := &staleLogListEvent{
 			Source:        daemon.config.LogListSource,
 			LastSuccess:   daemon.logsLoadedAt,
 			LastError:     daemon.logListError,
 			LastErrorTime: daemon.logListErrorAt,
-		}); err != nil {
+			TextPath:      textPath,
+		}
+		if err := event.save(); err != nil {
+			return fmt.Errorf("error saving stale log list event: %w", err)
+		}
+		if err := notify(ctx, daemon.config, event); err != nil {
 			return fmt.Errorf("error notifying about stale log list: %w", err)
 		}
 	}

monitor/healthcheck.go

@@ -22,11 +22,16 @@ import (
 	"software.sslmate.com/src/certspotter/loglist"
 )
 
+func healthCheckFilename() string {
+	return time.Now().UTC().Format(time.RFC3339) + ".txt"
+}
+
 func healthCheckLog(ctx context.Context, config *Config, ctlog *loglist.Log) error {
 	var (
 		stateDirPath  = filepath.Join(config.StateDir, "logs", ctlog.LogID.Base64URLString())
 		stateFilePath = filepath.Join(stateDirPath, "state.json")
 		sthsDirPath   = filepath.Join(stateDirPath, "unverified_sths")
+		textPath      = filepath.Join(stateDirPath, "healthchecks", healthCheckFilename())
 	)
 	state, err := loadStateFile(stateFilePath)
 	if errors.Is(err, fs.ErrNotExist) {
@@ -45,19 +50,29 @@ func healthCheckLog(ctx context.Context, config *Config, ctlog *loglist.Log) err
 	}
 
 	if len(sths) == 0 {
-		if err := notify(ctx, config, &staleSTHEvent{
+		event := &staleSTHEvent{
 			Log:         ctlog,
 			LastSuccess: state.LastSuccess,
 			LatestSTH:   state.VerifiedSTH,
-		}); err != nil {
+			TextPath:    textPath,
+		}
+		if err := event.save(); err != nil {
+			return fmt.Errorf("error saving stale STH event: %w", err)
+		}
+		if err := notify(ctx, config, event); err != nil {
 			return fmt.Errorf("error notifying about stale STH: %w", err)
 		}
 	} else {
-		if err := notify(ctx, config, &backlogEvent{
+		event := &backlogEvent{
 			Log:       ctlog,
 			LatestSTH: sths[len(sths)-1],
 			Position:  state.DownloadPosition.Size(),
-		}); err != nil {
+			TextPath:  textPath,
+		}
+		if err := event.save(); err != nil {
+			return fmt.Errorf("error saving backlog event: %w", err)
+		}
+		if err := notify(ctx, config, event); err != nil {
 			return fmt.Errorf("error notifying about backlog: %w", err)
 		}
 	}
@@ -69,17 +84,20 @@ type staleSTHEvent struct {
 	Log         *loglist.Log
 	LastSuccess time.Time
 	LatestSTH   *ct.SignedTreeHead // may be nil
+	TextPath    string
 }
 type backlogEvent struct {
 	Log       *loglist.Log
 	LatestSTH *ct.SignedTreeHead
 	Position  uint64
+	TextPath  string
 }
 type staleLogListEvent struct {
 	Source        string
 	LastSuccess   time.Time
 	LastError     string
 	LastErrorTime time.Time
+	TextPath      string
 }
 
 func (e *backlogEvent) Backlog() uint64 {
@@ -89,18 +107,21 @@ func (e *backlogEvent) Backlog() uint64 {
 func (e *staleSTHEvent) Environ() []string {
 	return []string{
 		"EVENT=error",
+		"TEXT_FILENAME=" + e.TextPath,
 		"SUMMARY=" + fmt.Sprintf("unable to contact %s since %s", e.Log.URL, e.LastSuccess),
 	}
 }
 func (e *backlogEvent) Environ() []string {
 	return []string{
 		"EVENT=error",
+		"TEXT_FILENAME=" + e.TextPath,
 		"SUMMARY=" + fmt.Sprintf("backlog of size %d from %s", e.Backlog(), e.Log.URL),
 	}
 }
 func (e *staleLogListEvent) Environ() []string {
 	return []string{
 		"EVENT=error",
+		"TEXT_FILENAME=" + e.TextPath,
 		"SUMMARY=" + fmt.Sprintf("unable to retrieve log list since %s: %s", e.LastSuccess, e.LastError),
 	}
 }
@@ -149,4 +170,14 @@ func (e *staleLogListEvent) Text() string {
 	return text.String()
 }
 
+func (e *staleSTHEvent) save() error {
+	return writeTextFile(e.TextPath, e.Text(), 0666)
+}
+func (e *backlogEvent) save() error {
+	return writeTextFile(e.TextPath, e.Text(), 0666)
+}
+func (e *staleLogListEvent) save() error {
+	return writeTextFile(e.TextPath, e.Text(), 0666)
+}
+
 // TODO-3: make the errors more actionable

monitor/monitor.go

@@ -78,8 +78,9 @@ func monitorLog(ctx context.Context, config *Config, ctlog *loglist.Log, logClie
 		stateFilePath       = filepath.Join(stateDirPath, "state.json")
 		sthsDirPath         = filepath.Join(stateDirPath, "unverified_sths")
 		malformedDirPath    = filepath.Join(stateDirPath, "malformed_entries")
+		healthchecksDirPath = filepath.Join(stateDirPath, "healthchecks")
 	)
-	for _, dirPath := range []string{stateDirPath, sthsDirPath, malformedDirPath} {
+	for _, dirPath := range []string{stateDirPath, sthsDirPath, malformedDirPath, healthchecksDirPath} {
 		if err := os.Mkdir(dirPath, 0777); err != nil && !errors.Is(err, fs.ErrExist) {
 			return fmt.Errorf("error creating state directory: %w", err)
 		}

monitor/statedir.go

@@ -145,7 +145,7 @@ func prepareStateDir(stateDir string) error {
 		return fmt.Errorf("%s was created by a newer version of certspotter; upgrade to the latest version of certspotter or remove this directory to start from scratch", stateDir)
 	}
 
-	for _, subdir := range []string{"certs", "logs"} {
+	for _, subdir := range []string{"certs", "logs", "healthchecks"} {
 		if err := os.Mkdir(filepath.Join(stateDir, subdir), 0777); err != nil && !errors.Is(err, fs.ErrExist) {
 			return err
 		}