syslog: local syslog and stdout redirection (#344)

Author: jkellerer

config/global.go

@@ -26,7 +26,7 @@ type Global struct {
 	MinMemory            uint64              `mapstructure:"min-memory" default:"100" description:"Minimum available memory (in MB) required to run any commands - see https://creativeprojects.github.io/resticprofile/usage/memory/"`
 	Scheduler            string              `mapstructure:"scheduler" description:"Leave blank for the default scheduler or use \"crond\" to select cron on supported operating systems"`
 	ScheduleDefaults     *ScheduleBaseConfig `mapstructure:"schedule-defaults" default:"" description:"Sets defaults for all schedules"`
-	Log                  string              `mapstructure:"log" default:"" description:"Sets the default log destination to be used if not specified in '--log' or 'schedule-log' - see https://creativeprojects.github.io/resticprofile/configuration/logs/"`
+	Log                  string              `mapstructure:"log" default:"" examples:"/resticprofile.log;syslog-tcp://syslog-server:514;syslog:server;syslog:" description:"Sets the default log destination to be used if not specified in '--log' or 'schedule-log' - see https://creativeprojects.github.io/resticprofile/configuration/logs/"`
 	LegacyArguments      bool                `mapstructure:"legacy-arguments" default:"false" deprecated:"0.20.0" description:"Legacy, broken arguments mode of resticprofile before version 0.15"`
 	SystemdUnitTemplate  string              `mapstructure:"systemd-unit-template" default:"" description:"File containing the go template to generate a systemd unit - see https://creativeprojects.github.io/resticprofile/schedules/systemd/"`
 	SystemdTimerTemplate string              `mapstructure:"systemd-timer-template" default:"" description:"File containing the go template to generate a systemd timer - see https://creativeprojects.github.io/resticprofile/schedules/systemd/"`

config/profile.go

@@ -298,7 +298,7 @@ type ScheduleBaseSection struct {
 	scheduleConfig                  *ScheduleConfig
 	Schedule                        any            `mapstructure:"schedule" show:"noshow" examples:"hourly;daily;weekly;monthly;10:00,14:00,18:00,22:00;Wed,Fri 17:48;*-*-15 02:45;Mon..Fri 00:30" description:"Configures the scheduled execution of this profile section. Can be times in systemd timer format or a config structure"`
 	SchedulePermission              string         `mapstructure:"schedule-permission" show:"noshow" default:"auto" enum:"auto;system;user;user_logged_on" description:"Specify whether the schedule runs with system or user privileges - see https://creativeprojects.github.io/resticprofile/schedules/configuration/"`
-	ScheduleLog                     string         `mapstructure:"schedule-log" show:"noshow" examples:"/resticprofile.log;tcp://localhost:514" description:"Redirect the output into a log file or to syslog when running on schedule"`
+	ScheduleLog                     string         `mapstructure:"schedule-log" show:"noshow" examples:"/resticprofile.log;syslog-tcp://syslog-server:514;syslog:server;syslog:" description:"Redirect the output into a log file or to syslog when running on schedule"`
 	SchedulePriority                string         `mapstructure:"schedule-priority" show:"noshow" default:"background" enum:"background;standard" description:"Set the priority at which the schedule is run"`
 	ScheduleLockMode                string         `mapstructure:"schedule-lock-mode" show:"noshow" default:"default" enum:"default;fail;ignore" description:"Specify how locks are used when running on schedule - see https://creativeprojects.github.io/resticprofile/schedules/configuration/"`
 	ScheduleLockWait                maybe.Duration `mapstructure:"schedule-lock-wait" show:"noshow" examples:"150s;15m;30m;45m;1h;2h30m" description:"Set the maximum time to wait for acquiring locks when running on schedule"`

config/schedule.go

@@ -35,7 +35,7 @@ const (
 // ScheduleBaseConfig is the base user configuration that could be shared across all schedules.
 type ScheduleBaseConfig struct {
 	Permission              string         `mapstructure:"permission" default:"auto" enum:"auto;system;user;user_logged_on" description:"Specify whether the schedule runs with system or user privileges - see https://creativeprojects.github.io/resticprofile/schedules/configuration/"`
-	Log                     string         `mapstructure:"log" examples:"/resticprofile.log;tcp://localhost:514" description:"Redirect the output into a log file or to syslog when running on schedule"`
+	Log                     string         `mapstructure:"log" examples:"/resticprofile.log;syslog-tcp://syslog-server:514;syslog:server;syslog:" description:"Redirect the output into a log file or to syslog when running on schedule"`
 	Priority                string         `mapstructure:"priority" default:"background" enum:"background;standard" description:"Set the priority at which the schedule is run"`
 	LockMode                string         `mapstructure:"lock-mode" default:"default" enum:"default;fail;ignore" description:"Specify how locks are used when running on schedule - see https://creativeprojects.github.io/resticprofile/schedules/configuration/"`
 	LockWait                maybe.Duration `mapstructure:"lock-wait" examples:"150s;15m;30m;45m;1h;2h30m" description:"Set the maximum time to wait for acquiring locks when running on schedule"`

dial/url.go

@@ -1,18 +1,40 @@
 package dial
 
-import "net/url"
+import (
+	"net/url"
+	"slices"
+	"strings"
+
+	"github.com/creativeprojects/clog"
+)
+
+var validSchemes = []string{
+	"udp",
+	"tcp",
+	"syslog",     // local or UDP
+	"syslog-tcp", // TCP
+	// "syslog-tls", reserved for future support
+}
+
+var noHostAllowed = []string{
+	"syslog",
+}
 
 // GetAddr returns scheme, host&port, isURL
 func GetAddr(source string) (scheme, hostPort string, isURL bool) {
 	URL, err := url.Parse(source)
-	if err != nil {
-		return "", "", false
-	}
-	// need a minimum of udp://:12
-	if len(URL.Scheme) < 3 || len(URL.Host) < 3 {
-		return "", "", false
+	if err == nil {
+		scheme = strings.ToLower(URL.Scheme)
+		hostPort = URL.Host
+		schemeOk := slices.Contains(validSchemes, scheme)
+		hostOk := len(hostPort) >= 3 || slices.Contains(noHostAllowed, scheme)
+		if isURL = schemeOk && hostOk; isURL {
+			return
+		}
+	} else {
+		clog.Tracef("is not an URL %q", source)
 	}
-	return URL.Scheme, URL.Host, true
+	return "", "", false
 }
 
 func IsURL(source string) bool {

dial/url_test.go

@@ -16,13 +16,24 @@ func TestGetDialAddr(t *testing.T) {
 	}{
 		// invalid
 		{"://", "", "", false},
+		// supported schemes
+		{"TCP://:123", "tcp", ":123", true},
+		{"UDP://:123", "udp", ":123", true},
+		{"tcp://:123", "tcp", ":123", true},
+		{"udp://:123", "udp", ":123", true},
+		{"syslog://:123", "syslog", ":123", true},
+		{"syslog-tcp://:123", "syslog-tcp", ":123", true},
 		// url
-		{"scheme://:123", "scheme", ":123", true},
-		{"scheme://host:123", "scheme", "host:123", true},
-		{"scheme://host", "scheme", "host", true},
+		{"syslog://:123", "syslog", ":123", true},
+		{"syslog://host:123", "syslog", "host:123", true},
+		{"syslog://host", "syslog", "host", true},
+		{"syslog://", "syslog", "", true},
+		{"syslog:", "syslog", "", true},
 		// too short
-		{"scheme://", "", "", false},
-		{"scheme://:", "", "", false},
+		{"tcp://", "", "", false},
+		{"tcp:", "", "", false},
+		{"syslog-tcp:", "", "", false},
+		{"udp:", "", "", false},
 		{"c://", "", "", false},
 		{"c://:", "", "", false},
 		{"c://:123", "", "", false},

docs/content/configuration/logs.md

@@ -14,7 +14,7 @@ The log destination syntax is a such:
 * `-` {{% icon icon="arrow-right" %}} redirects all the logs to the console / stdout (is the default log destination)
 * `filename` {{% icon icon="arrow-right" %}} redirects all the logs to the local file called **filename**
 * `temp:filename` {{% icon icon="arrow-right" %}} redirects all the logs to a temporary file available during the whole session, and deleted afterwards.
-* `tcp://syslog_server:514` or `udp://syslog_server:514` {{% icon icon="arrow-right" %}} redirects all the logs to the **syslog** server.
+* `syslog:`, `syslog://syslog_server[:514]` or `syslog-tcp://syslog_server[:514]` {{% icon icon="arrow-right" %}} redirects all the logs to a local or remote **syslog** server. Alternative configurations for remote servers are: `udp://syslog_server:514` & `tcp://syslog_server:514`.
 
 {{% notice style="note" %}}
 Logging to syslog is not available on Windows.
@@ -36,6 +36,8 @@ version = "1"
 
 [global]
 log = "resticprofile.log"
+[global.schedule-defaults]
+log = "scheduled-resticprofile.log"
 ```
 
 {{% /tab %}}
@@ -46,6 +48,8 @@ version: "1"
 
 global:
   log: "resticprofile.log"
+  schedule-defaults:
+    log: "scheduled-resticprofile.log"
 ```
 
 {{% /tab %}}
@@ -54,6 +58,9 @@ global:
 ```hcl
 "global" {
   "log" = "resticprofile.log"
+  "schedule-defaults" {
+    "log" = "scheduled-resticprofile.log"
+  }
 }
 ```
 
@@ -64,7 +71,10 @@ global:
 {
   "version": "1",
   "global": {
-    "log": "resticprofile.log"
+    "log": "resticprofile.log",
+    "schedule-defaults": {
+      "log": "scheduled-resticprofile.log"
+    }
   }
 }
 ```

logger.go

@@ -48,7 +48,7 @@ func setupTargetLogger(flags commandLineFlags, logTarget string) (io.Closer, err
 	)
 	scheme, hostPort, isURL := dial.GetAddr(logTarget)
 	if isURL {
-		handler, err = getSyslogHandler(scheme, hostPort)
+		handler, file, err = getSyslogHandler(scheme, hostPort)
 	} else {
 		handler, file, err = getFileHandler(logTarget)
 	}

syslog.go

@@ -3,9 +3,13 @@
 package main
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
+	"io"
 	"log/syslog"
+	"net"
+	"strings"
 
 	"github.com/creativeprojects/clog"
 	"github.com/creativeprojects/resticprofile/constants"
@@ -48,11 +52,58 @@ func (l *Syslog) Close() error {
 
 var _ LogCloser = &Syslog{}
 
-func getSyslogHandler(scheme, hostPort string) (*Syslog, error) {
-	writer, err := syslog.Dial(scheme, hostPort, syslog.LOG_USER|syslog.LOG_NOTICE, constants.ApplicationName)
-	if err != nil {
-		return nil, fmt.Errorf("cannot open syslog logger: %w", err)
+const DefaultSyslogPort = "514"
+
+type tokenWriter struct {
+	separator []byte
+	target    io.Writer
+}
+
+func (s *tokenWriter) Write(p []byte) (n int, err error) {
+	var pn int
+	for i, part := range bytes.Split(p, s.separator) {
+		if err != nil {
+			break
+		}
+		pn, err = s.target.Write(part)
+		n += pn
+		if i > 0 {
+			n += len(s.separator)
+		}
+	}
+	return
+}
+
+func getSyslogHandler(scheme, hostPort string) (handler *Syslog, writer io.Writer, err error) {
+	switch scheme {
+	case "udp", "tcp":
+	case "syslog-tcp":
+		scheme = "tcp"
+	case "syslog":
+		if len(hostPort) == 0 {
+			scheme = "local"
+		} else {
+			scheme = "udp"
+		}
+	default:
+		err = fmt.Errorf("unsupported scheme %q", scheme)
+	}
+
+	var logger *syslog.Writer
+	if scheme == "local" {
+		logger, err = syslog.New(syslog.LOG_USER|syslog.LOG_NOTICE, constants.ApplicationName)
+	} else {
+		if _, _, e := net.SplitHostPort(hostPort); e != nil && strings.Contains(e.Error(), "missing port") {
+			hostPort = net.JoinHostPort(hostPort, DefaultSyslogPort)
+		}
+		logger, err = syslog.Dial(scheme, hostPort, syslog.LOG_USER|syslog.LOG_NOTICE, constants.ApplicationName)
+	}
+
+	if err == nil {
+		writer = &tokenWriter{separator: []byte("\n"), target: logger}
+		handler = NewSyslogHandler(logger)
+	} else {
+		err = fmt.Errorf("cannot open syslog logger: %w", err)
 	}
-	handler := NewSyslogHandler(writer)
-	return handler, nil
+	return
 }

syslog_windows.go

@@ -4,8 +4,10 @@ package main
 
 import (
 	"errors"
+	"io"
 )
 
-func getSyslogHandler(scheme, hostPort string) (LogCloser, error) {
-	return nil, errors.New("syslog is not supported on Windows")
+func getSyslogHandler(scheme, hostPort string) (_ LogCloser, _ io.Writer, err error) {
+	err = errors.New("syslog is not supported on Windows")
+	return
 }

wrapper.go

@@ -632,8 +632,8 @@ func (r *resticWrapper) runFinalShellCommands(command string, fail error) {
 			term.FlushAllOutput()
 			_, _, err := runShellCommand(rCommand)
 			if err != nil {
-				clog.Errorf("run-finally command %d/%d failed ('%s' on profile '%s'): %w",
-					index+1, len(commands), command, r.profile.Name, err)
+				clog.Errorf("run-finally command %d/%d failed ('%s' on profile '%s'): %s",
+					index+1, len(commands), command, r.profile.Name, err.Error())
 			}
 		}(i, commands[i])
 	}