fix port already in use

Author: aphralG

internal/datasource/config/nginx_config_parser.go

@@ -47,7 +47,8 @@ const (
 
 type (
 	NginxConfigParser struct {
-		agentConfig *config.Config
+		agentConfig             *config.Config
+		previousNAPSysLogServer string
 	}
 )
 
@@ -65,7 +66,8 @@ type (
 
 func NewNginxConfigParser(agentConfig *config.Config) *NginxConfigParser {
 	return &NginxConfigParser{
-		agentConfig: agentConfig,
+		agentConfig:             agentConfig,
+		previousNAPSysLogServer: "",
 	}
 }
 
@@ -176,7 +178,8 @@ func (ncp *NginxConfigParser) createNginxConfigContext(
 						slog.Info("args", "", directive.Args)
 						sysLogServers := ncp.findValidSysLogServers(directive.Args)
 						if len(sysLogServers) == 0 {
-							slog.WarnContext(ctx, "Could not find usable NAP syslog server, security violations will be unavailable")
+							slog.WarnContext(ctx, "Could not find usable NAP syslog server, "+
+								"security violations will be unavailable")
 						}
 						for i := range sysLogServers {
 							sysLogServer := sysLogServers[i]
@@ -209,6 +212,7 @@ func (ncp *NginxConfigParser) createNginxConfigContext(
 			syslogServer := ncp.parseSyslogDirective(ctx, napSyslogServersFound)
 			if syslogServer != "" {
 				nginxConfigContext.NAPSysLogServer = syslogServer
+				ncp.previousNAPSysLogServer = syslogServer
 			}
 		}
 
@@ -224,6 +228,12 @@ func (ncp *NginxConfigParser) createNginxConfigContext(
 }
 
 func (ncp *NginxConfigParser) parseSyslogDirective(ctx context.Context, napSyslogServers map[string]bool) string {
+	if ncp.previousNAPSysLogServer != "" {
+		if _, ok := napSyslogServers[ncp.previousNAPSysLogServer]; ok {
+			return ncp.previousNAPSysLogServer
+		}
+	}
+
 	for napSyslogServer := range napSyslogServers {
 		ln, err := net.Listen("tcp", napSyslogServer)
 		if err != nil {

internal/datasource/config/nginx_config_parser_test.go

@@ -601,11 +601,12 @@ func TestNginxConfigParser_SyslogServerParse(t *testing.T) {
 	instance.InstanceRuntime.ConfigPath = file.Name()
 
 	tests := []struct {
-		name                  string
-		content               string
-		expectedLog           string
-		expectedSyslogServers string
-		portInUse             bool
+		name                    string
+		content                 string
+		expectedLog             string
+		expectedSyslogServers   string
+		previousNAPSysLogServer string
+		portInUse               bool
 	}{
 		{
 			name:                  "Test 1: Valid port",
@@ -639,6 +640,15 @@ func TestNginxConfigParser_SyslogServerParse(t *testing.T) {
 			expectedLog: "Could not find usable NAP syslog server",
 			portInUse:   true,
 		},
+		{
+			name:                  "Test 5: Server hasn't changed",
+			expectedSyslogServers: "127.0.0.1:1515",
+			content: testconfig.NginxConfigWithMultipleSysLogs(errorLog.Name(), accessLog.Name(),
+				"my.domain.com:1517", "127.0.0.1:1515", "my.domain.com:1517"),
+			expectedLog:             "Found NAP syslog server",
+			portInUse:               true,
+			previousNAPSysLogServer: "127.0.0.1:1515",
+		},
 	}
 
 	for _, test := range tests {
@@ -649,6 +659,7 @@ func TestNginxConfigParser_SyslogServerParse(t *testing.T) {
 			agentConfig := types.AgentConfig()
 			agentConfig.AllowedDirectories = []string{dir}
 			nginxConfig := NewNginxConfigParser(agentConfig)
+			nginxConfig.previousNAPSysLogServer = test.previousNAPSysLogServer
 
 			writeErr := os.WriteFile(file.Name(), []byte(test.content), 0o600)
 			require.NoError(t, writeErr)