Log events: allow custom timestamps

README.md

@@ -63,10 +63,31 @@ $ curl localhost:3535/logs
 2024-10-23T12:04:07Z     this is a test
 ```
 
- ## Actions
+#### Event timestamps
 
- Actions are shell commands that can be executed via API. The commands are defined in the config file,
- see [systemapi-config.toml](./systemapi-config.toml) for examples.
+By default, events are timestamped with the current time. However, the timestamp can be overridden by
+providing a valid unix timestamp (in seconds or milliseconds) as first part of the message:
+
+```bash
+# Start the server
+$ go run cmd/system-api/main.go
+
+# Add regular event
+$ echo "hello world" > pipe.fifo
+
+# Add event with custom timestamp
+$ echo "1634966400 this is a test" > pipe.fifo
+
+# Query events
+$ curl localhost:3535/logs
+2024-11-21T19:48:04Z     hello world
+2021-10-23T05:20:00Z     this is a test          <--- custom timestamp on this entry
+```
+
+## Actions
+
+Actions are shell commands that can be executed via API. The commands are defined in the config file,
+see [systemapi-config.toml](./systemapi-config.toml) for examples.
 
 Actions are recorded in the event log.
 

systemapi/server.go

@@ -12,6 +12,7 @@ import (
 	"io"
 	"net/http"
 	"os"
+	"strconv"
 	"strings"
 	"sync"
 	"syscall"
@@ -205,11 +206,34 @@ func (s *Server) handleLivenessCheck(w http.ResponseWriter, r *http.Request) {
 func (s *Server) addEvent(event Event) {
 	// Add event to the list and prune if necessary
 	s.eventsLock.Lock()
+	defer s.eventsLock.Unlock()
+
+	// Trim whitespace from the message
+	event.Message = strings.TrimSpace(event.Message)
+	if len(event.Message) == 0 {
+		return
+	}
+
+	// Check for custom timestamp. If the first part of the message is a timestamp, use it instead of the current time.
+	// To be a timestamp, this must be an integer with 10 characters for seconds or 13 for milliseconds.
+	timestampStr := strings.Fields(event.Message)[0] // split by whitespace and take the first part
+	timeInt, err := strconv.ParseInt(timestampStr, 10, 64)
+	if err == nil {
+		if len(timestampStr) == 10 {
+			// timestamp in seconds, update event
+			event.ReceivedAt = time.Unix(timeInt, 0).UTC()
+			event.Message = strings.TrimSpace(event.Message[len(timestampStr):])
+		} else if len(timestampStr) == 13 {
+			// timestamp in milliseconds, update event
+			event.ReceivedAt = time.UnixMilli(timeInt).UTC()
+			event.Message = strings.TrimSpace(event.Message[len(timestampStr):])
+		}
+	}
+
 	s.events = append(s.events, event)
 	if len(s.events) > s.cfg.General.LogMaxEntries {
 		s.events = s.events[1:]
 	}
-	s.eventsLock.Unlock()
 }
 
 func (s *Server) addInternalEvent(msg string) {

systemapi/server_test.go

@@ -156,7 +156,7 @@ func TestBasicAuth(t *testing.T) {
 }
 
 func TestMaxEntries(t *testing.T) {
-	// Verify maximum number of log entries is working correctly
+	// Ensure maximum number of log entries is working correctly
 	maxEntries := 5
 
 	cfg := NewConfig()
@@ -177,3 +177,37 @@ func TestMaxEntries(t *testing.T) {
 	require.Equal(t, "4", srv.events[3].Message)
 	require.Equal(t, "5", srv.events[4].Message)
 }
+
+func TestAddEntryMessageParsing(t *testing.T) {
+	// Ensure that messages with timestamps are correctly parsed
+	srv := newTestServer(t)
+
+	testTime1 := time.Date(2021, 1, 2, 3, 4, 5, 0, time.UTC)
+	testTime2 := time.Date(2022, 1, 2, 3, 4, 6, 0, time.UTC)
+	testTime2TimestampSec := testTime2.Unix()
+	testTime2TimestampMs := testTime2.UnixMilli()
+
+	// Add messages
+	srv.addEvent(Event{ReceivedAt: testTime1, Message: "1"})                                                // regular message
+	srv.addEvent(Event{ReceivedAt: testTime1, Message: fmt.Sprintf("%d 2", testTime2TimestampSec)})         // custom timestamp
+	srv.addEvent(Event{ReceivedAt: testTime1, Message: fmt.Sprintf("%d \t  3  \t ", testTime2TimestampMs)}) // custom timestamp, with whitespace to test trimming
+
+	// Add empty messages to ensure they are ignored
+	srv.addEvent(Event{ReceivedAt: testTime1, Message: ""})      // empty message
+	srv.addEvent(Event{ReceivedAt: testTime1, Message: "  \t "}) // empty message
+
+	// 3 proper entries were added
+	require.Len(t, srv.events, 3)
+
+	// Check entry 1 (regular message)
+	require.Equal(t, "1", srv.events[0].Message)
+	require.Equal(t, testTime1, srv.events[0].ReceivedAt)
+
+	// Check entry 2 (timestamp in seconds)
+	require.Equal(t, "2", srv.events[1].Message)
+	require.Equal(t, testTime2, srv.events[1].ReceivedAt)
+
+	// Check entry 3 (timestamp in milliseconds)
+	require.Equal(t, "3", srv.events[2].Message) // check that whitespace was trimmed
+	require.Equal(t, testTime2, srv.events[2].ReceivedAt)
+}