From f345349a74d0af33faa286751cf05812f9e161e4 Mon Sep 17 00:00:00 2001
From: Gabriel Mougard <gabriel.mougard@canonical.com>
Date: Wed, 23 Oct 2024 11:53:02 +0200
Subject: [PATCH] lxd/network/acl: Allow 'ovnParseLogEntry' to read a log input
 using an external timestamp

When reading a log file, the logtime (timestamp of the log entry) is part of the entry but when we read a syslog, the logtime is not contained
in the log entry fields and need to be parsed and converted.

We added two local functions to cope with these two usages:
* 'parseLogTimeFromFields'
* 'parseLogTimeFromTimestamp' (used when the OVN deployment is part of MicroOVN and we need to read the syslog)

Signed-off-by: Gabriel Mougard <gabriel.mougard@canonical.com>
---
 lxd/network/acl/acl_ovn.go       | 35 +++++++++++++++++++++++++++-----
 lxd/network/acl/driver_common.go |  2 +-
 2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/lxd/network/acl/acl_ovn.go b/lxd/network/acl/acl_ovn.go
index 0a3b19b22f7e..e5b846a351fc 100644
--- a/lxd/network/acl/acl_ovn.go
+++ b/lxd/network/acl/acl_ovn.go
@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net"
+	"strconv"
 	"strings"
 	"time"
 
@@ -1042,7 +1043,23 @@ type ovnLogEntry struct {
 }
 
 // ovnParseLogEntry takes a log line and expected ACL prefix and returns a re-formated log entry if matching.
-func ovnParseLogEntry(input string, prefix string) string {
+// The 'timestamp' string is in microseconds format. If empty, the timestamp is extracted from the log entry.
+func ovnParseLogEntry(input string, timestamp string, prefix string) string {
+	parseLogTimeFromFields := func(fields []string) (time.Time, error) {
+		return time.Parse(time.RFC3339, fields[0])
+	}
+
+	parseLogTimeFromTimestamp := func(timestamp string) (time.Time, error) {
+		tsInt, err := strconv.ParseInt(timestamp, 10, 64)
+		if err != nil {
+			return time.Time{}, fmt.Errorf("Failed to parse timestamp: %w", err)
+		}
+
+		// The provided timestamp is in microseconds and need to be converted to nanoseconds.
+		tsNs := tsInt * 1000
+		return time.Unix(0, tsNs).UTC(), nil
+	}
+
 	fields := strings.Split(input, "|")
 
 	// Skip unknown formatting.
@@ -1071,10 +1088,18 @@ func ovnParseLogEntry(input string, prefix string) string {
 		return ""
 	}
 
-	// Parse the timestamp.
-	logTime, err := time.Parse(time.RFC3339, fields[0])
-	if err != nil {
-		return ""
+	var logTime time.Time
+	var err error
+	if timestamp == "" {
+		logTime, err = parseLogTimeFromFields(fields)
+		if err != nil {
+			return ""
+		}
+	} else {
+		logTime, err = parseLogTimeFromTimestamp(timestamp)
+		if err != nil {
+			return ""
+		}
 	}
 
 	// Get the protocol.
diff --git a/lxd/network/acl/driver_common.go b/lxd/network/acl/driver_common.go
index 9d863a3c29a0..332da23aad13 100644
--- a/lxd/network/acl/driver_common.go
+++ b/lxd/network/acl/driver_common.go
@@ -767,7 +767,7 @@ func (d *common) GetLog(clientType request.ClientType) (string, error) {
 	logEntries := []string{}
 	scanner := bufio.NewScanner(logFile)
 	for scanner.Scan() {
-		logEntry := ovnParseLogEntry(scanner.Text(), fmt.Sprintf("lxd_acl%d-", d.id))
+		logEntry := ovnParseLogEntry(scanner.Text(), "", fmt.Sprintf("lxd_acl%d-", d.id))
 		if logEntry == "" {
 			continue
 		}