go_goutils/logging/funcs.go
2021-02-26 20:27:35 -05:00

131 lines
3.1 KiB
Go

package logging
import (
native `log`
`os`
`path`
"r00t2.io/goutils/types"
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)
}
return
}
func testOpen(path string) (success bool, err error) {
var f *os.File
// Example #2, https://golang.org/pkg/os/#OpenFile
if f, err = os.OpenFile(path, appendFlags, logPerm); err != nil {
return
}
defer f.Close()
success = true
return
}