Reduce scope

There is no need to have the timestamp into the exporter. Just
keep the transaction number. If the transaction number does not
change, it is enough to see the issue.

README

@@ -7,8 +7,8 @@ This is appropriate for monitoring on a server in which you do not want to store
 You should add other monitoring tools to check consistency with other exporters.
 
 ## Features
-- Metrics for the last transaction timestamp and number for each repository.
-- Configurable via a JSON file.
+- Metrics for the last transaction number for each repository.
+- Configurable via a JSON file for multiple repos
 
 ## Usage
 
@@ -23,11 +23,10 @@ You should add other monitoring tools to check consistency with other exporters.
     ```
 2. Run the exporter:
     ```bash
-    ./borgbackuptransactions_exporter --config=config.json
+    ./borgbackuptransactions_exporter -config=config.json
     ```
 
 ### Metrics exposed
-- `borgbackup_last_transaction_timestamp`
 - `borgbackup_last_transaction_number`
 
 ### How to scrape

main.go

@@ -37,13 +37,6 @@ const (
 )
 
 var (
-	lastTransactionTimestamp = prometheus.NewGaugeVec(
-		prometheus.GaugeOpts{
-			Name: "borgbackup_last_transaction_timestamp",
-			Help: "Unix timestamp of the last transaction in the BorgBackup repository",
-		},
-		[]string{"repo"},
-	)
 	lastTransactionNumber = prometheus.NewGaugeVec(
 		prometheus.GaugeOpts{
 			Name: "borgbackup_last_transaction_number",
@@ -54,7 +47,6 @@ var (
 )
 
 func init() {
-	prometheus.MustRegister(lastTransactionTimestamp)
 	prometheus.MustRegister(lastTransactionNumber)
 }
 
@@ -187,33 +179,26 @@ func updateRepoMetrics(repo string) {
   // instead of deferring as usual, close as soon as the 
   file.Close()
 
-	transactionNumber, timestamp, err := parseTransactionLine(lastLine)
+	transactionNumber, err := parseTransactionLine(lastLine)
 	if err != nil {
 		log.Printf("Failed to parse transactions file for repo %s: %v", repo, err)
 		return
 	}
 
-	lastTransactionTimestamp.WithLabelValues(repo).Set(float64(timestamp))
 	lastTransactionNumber.WithLabelValues(repo).Set(float64(transactionNumber))
 }
 
-func parseTransactionLine(line string) (int, int64, error) {
+func parseTransactionLine(line string) (int, error) {
 	parts := strings.Split(line, ",")
 	if len(parts) < 2 {
-		return 0, 0, fmt.Errorf("invalid line format: %s", line)
+		return 0, fmt.Errorf("invalid line format: %s", line)
 	}
 
 	numberStr := strings.TrimPrefix(parts[0], "transaction ")
 	transactionNumber, err := strconv.Atoi(strings.TrimSpace(numberStr))
 	if err != nil {
-		return 0, 0, fmt.Errorf("failed to parse transaction number: %v", err)
-	}
-
-	timeStr := strings.TrimSpace(strings.Replace(parts[1], "UTC time", "", -1))
-	t, err := time.Parse("2006-01-02T15:04:05.000000", timeStr)
-	if err != nil {
-		return 0, 0, fmt.Errorf("failed to parse UTC time: %v", err)
+		return 0, fmt.Errorf("failed to parse transaction number: %v", err)
 	}
 
-	return transactionNumber, t.Unix(), nil
+	return transactionNumber, nil
 }

main_test.go

@@ -2,25 +2,25 @@ package main
 
 import (
 	"testing"
-	"time"
 )
 
 func TestParseTransactionLine(t *testing.T) {
 	line := "transaction 6374, UTC time 2024-11-30T11:45:36.870201"
-	number, timestamp, err := parseTransactionLine(line)
+	// number, timestamp, err := parseTransactionLine(line)
+	number, err := parseTransactionLine(line)
 	if err != nil {
 		t.Fatalf("Expected no error, got %v", err)
 	}
 
 	expectedNumber := 6374
-	expectedTime := time.Date(2024, 11, 30, 11, 45, 36, 870201000, time.UTC).Unix()
+	// expectedTime := time.Date(2024, 11, 30, 11, 45, 36, 870201000, time.UTC).Unix()
 
 	if number != expectedNumber {
 		t.Errorf("Expected transaction number %d, got %d", expectedNumber, number)
 	}
 
-	if timestamp != expectedTime {
+	/* if timestamp != expectedTime {
 		t.Errorf("Expected timestamp %d, got %d", expectedTime, timestamp)
-	}
+	} */
 }