do bitmask better, add (COMPLETELY 100% EXPERIMENTAL NOT DONE YET) eventlog support to logger

2021-12-15 04:49:03 -05:00
parent d5b1d449e5
commit 3975f8b11f
17 changed files with 698 additions and 224 deletions
--- a/logging/funcs_linux.go
+++ b/logging/funcs_linux.go
@@ -0,0 +1,123 @@
+package logging
+
+import (
+	native `log`
+	`os`
+	`path`
+
+	sysd `github.com/coreos/go-systemd/journal`
+	`r00t2.io/sysutils/paths`
+)
+
+var (
+	_ = sysd.Enabled()
+	_ = native.Logger{}
+	_ = os.Interrupt
+)
+
+/*
+	GetLogger returns an instance of Logger that best suits your system's capabilities.
+	If enableDebug is true, debug messages (which according to your program may or may not contain sensitive data) are rendered and written.
+	If prefix is "\x00" (a null byte), then the default logging prefix will be used. If anything else, even an empty string,
+	is specified then that will be used instead for the prefix.
+	logPaths is an (optional) list of strings to use as paths to test for writing. If the file can be created/written to,
+	it will be used (assuming you have no higher-level loggers available). Only the first logPaths entry that "works" will be used, later entries will be ignored.
+*/
+func GetLogger(enableDebug bool, prefix string, logPaths ...string) (logger Logger, err error) {
+
+	var logPath string
+	var logFlags types.MaskBit
+
+	// Configure system-supported logger(s).
+	if sysd.Enabled() {
+		// Use Journald.
+		logFlags.AddFlag(LogJournald)
+	} else {
+		// If we can detect syslog, use that. If not, try to use a file logger (+ stdout).
+		// Last ditch, stdout.
+		var hasSyslog bool
+		var stat os.FileInfo
+		var devlogPath string = devlog
+
+		if hasSyslog, stat, err = paths.RealPathExistsStat(&devlogPath); hasSyslog && err != nil {
+			return
+		}
+
+		if hasSyslog && !stat.Mode().IsRegular() {
+			logFlags.AddFlag(LogSyslog)
+		} else {
+			var exists bool
+			var success bool
+			var ckLogPaths []string
+
+			logFlags.AddFlag(LogStdout)
+			ckLogPaths = defLogPaths
+			if logPaths != nil {
+				ckLogPaths = logPaths
+			}
+			for _, p := range ckLogPaths {
+				if exists, _ = paths.RealPathExists(&p); exists {
+					if success, err = testOpen(p); err != nil {
+						continue
+					} else if !success {
+						continue
+					}
+					logFlags.AddFlag(LogFile)
+					logPath = p
+					break
+				} else {
+					dirPath := path.Dir(p)
+					if err = paths.MakeDirIfNotExist(&dirPath); err != nil {
+						continue
+					}
+					if success, err = testOpen(p); err != nil {
+						continue
+					} else if !success {
+						continue
+					}
+					logFlags.AddFlag(LogFile)
+					logPath = p
+					break
+				}
+			}
+		}
+	}
+
+	if logFlags.HasFlag(LogJournald) {
+		logger = &SystemDLogger{
+			Prefix:      logPrefix,
+			EnableDebug: enableDebug,
+		}
+	} else {
+		if logFlags.HasFlag(LogSyslog) {
+			logger = &SyslogLogger{
+				Prefix:      logPrefix,
+				EnableDebug: enableDebug,
+			}
+		} else {
+			if logFlags.HasFlag(LogFile) {
+				logger = &FileLogger{
+					StdLogger: StdLogger{
+						Prefix:      logPrefix,
+						EnableDebug: enableDebug,
+					},
+					Path: logPath,
+				}
+			} else {
+				logger = &StdLogger{
+					Prefix:      logPrefix,
+					EnableDebug: enableDebug,
+				}
+			}
+		}
+	}
+
+	logger.Setup()
+	if prefix != "\x00" {
+		logger.SetPrefix(prefix)
+	}
+
+	logger.Info("logger initialized of type %T with prefix %v", logger, logger.GetPrefix())
+
+	return
+}