From 93ca622a379515fcb2ed3b483610dcf5506f0d12 Mon Sep 17 00:00:00 2001
From: Andrew Ayer <andrew@sslmate.com>
Date: Thu, 4 Apr 2024 08:09:00 -0400
Subject: [PATCH] Add NotifyError to StateProvider

---
 monitor/daemon.go  |  2 +-
 monitor/errors.go  | 14 ++++++++++++--
 monitor/fsstate.go | 10 ++++++++++
 monitor/monitor.go |  8 ++++----
 monitor/state.go   |  4 ++++
 5 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/monitor/daemon.go b/monitor/daemon.go
index 2b47c16..79ca9ff 100644
--- a/monitor/daemon.go
+++ b/monitor/daemon.go
@@ -144,7 +144,7 @@ func (daemon *daemon) run(ctx context.Context) error {
 			if err := daemon.loadLogList(ctx); err != nil {
 				daemon.logListError = err.Error()
 				daemon.logListErrorAt = time.Now()
-				recordError(fmt.Errorf("error reloading log list (will try again later): %w", err))
+				recordError(ctx, daemon.config, nil, fmt.Errorf("error reloading log list (will try again later): %w", err))
 			}
 			reloadLogListTicker.Reset(reloadLogListInterval())
 		case <-healthCheckTicker.C:
diff --git a/monitor/errors.go b/monitor/errors.go
index f43df1a..c62b874 100644
--- a/monitor/errors.go
+++ b/monitor/errors.go
@@ -10,9 +10,19 @@
 package monitor
 
 import (
+	"context"
 	"log"
+
+	"software.sslmate.com/src/certspotter/loglist"
 )
 
-func recordError(err error) {
-	log.Print(err)
+func recordError(ctx context.Context, config *Config, ctlog *loglist.Log, errToRecord error) {
+	if err := config.State.NotifyError(ctx, ctlog, errToRecord); err != nil {
+		log.Printf("unable to notify about error: ", err)
+		if ctlog == nil {
+			log.Print(errToRecord)
+		} else {
+			log.Print(ctlog.URL, ": ", errToRecord)
+		}
+	}
 }
diff --git a/monitor/fsstate.go b/monitor/fsstate.go
index 550ba5b..70a2962 100644
--- a/monitor/fsstate.go
+++ b/monitor/fsstate.go
@@ -16,6 +16,7 @@ import (
 	"errors"
 	"fmt"
 	"io/fs"
+	"log"
 	"os"
 	"path/filepath"
 	"strings"
@@ -227,3 +228,12 @@ func (s *FilesystemState) NotifyHealthCheckFailure(ctx context.Context, ctlog *l
 	}
 	return nil
 }
+
+func (s *FilesystemState) NotifyError(ctx context.Context, ctlog *loglist.Log, err error) error {
+	if ctlog == nil {
+		log.Print(err)
+	} else {
+		log.Print(ctlog.URL, ":", err)
+	}
+	return nil
+}
diff --git a/monitor/monitor.go b/monitor/monitor.go
index 3c65670..3877d1f 100644
--- a/monitor/monitor.go
+++ b/monitor/monitor.go
@@ -79,7 +79,7 @@ func monitorLog(ctx context.Context, config *Config, ctlog *loglist.Log, logClie
 	if isFatalLogError(err) {
 		return err
 	} else if err != nil {
-		recordError(fmt.Errorf("error fetching latest STH for %s: %w", ctlog.URL, err))
+		recordError(ctx, config, ctlog, fmt.Errorf("error fetching latest STH: %w", err))
 		return nil
 	}
 	latestSTH.LogID = ctlog.LogID
@@ -97,7 +97,7 @@ func monitorLog(ctx context.Context, config *Config, ctlog *loglist.Log, logClie
 			if isFatalLogError(err) {
 				return err
 			} else if err != nil {
-				recordError(fmt.Errorf("error reconstructing tree of size %d for %s: %w", latestSTH.TreeSize, ctlog.URL, err))
+				recordError(ctx, config, ctlog, fmt.Errorf("error reconstructing tree of size %d: %w", latestSTH.TreeSize, err))
 				return nil
 			}
 			state = &LogState{
@@ -180,7 +180,7 @@ func monitorLog(ctx context.Context, config *Config, ctlog *loglist.Log, logClie
 
 		for len(sths) > 0 && state.DownloadPosition.Size() == sths[0].TreeSize {
 			if merkletree.Hash(sths[0].SHA256RootHash) != rootHash {
-				recordError(fmt.Errorf("error verifying %s at tree size %d: the STH root hash (%x) does not match the entries returned by the log (%x)", ctlog.URL, sths[0].TreeSize, sths[0].SHA256RootHash, rootHash))
+				recordError(ctx, config, ctlog, fmt.Errorf("error verifying at tree size %d: the STH root hash (%x) does not match the entries returned by the log (%x)", sths[0].TreeSize, sths[0].SHA256RootHash, rootHash))
 
 				state.DownloadPosition = state.VerifiedPosition
 				if err := config.State.StoreLogState(ctx, ctlog.LogID, state); err != nil {
@@ -209,7 +209,7 @@ func monitorLog(ctx context.Context, config *Config, ctlog *loglist.Log, logClie
 	if isFatalLogError(downloadErr) {
 		return downloadErr
 	} else if downloadErr != nil {
-		recordError(fmt.Errorf("error downloading entries from %s: %w", ctlog.URL, downloadErr))
+		recordError(ctx, config, ctlog, fmt.Errorf("error downloading entries: %w", downloadErr))
 		return nil
 	}
 
diff --git a/monitor/state.go b/monitor/state.go
index a5921ee..6595988 100644
--- a/monitor/state.go
+++ b/monitor/state.go
@@ -60,4 +60,8 @@ type StateProvider interface {
 	// Called when a health check fails.  The log is nil if the
 	// feailure is not associated with a log.
 	NotifyHealthCheckFailure(context.Context, *loglist.Log, HealthCheckFailure) error
+
+	// Called when an error occurs.  The log is nil if the error is
+	// not associated with a log.  Note that most errors are transient.
+	NotifyError(context.Context, *loglist.Log, error) error
 }