/*
InitJsonLogger creates and returns a logger suitable for logging JSON
data. Bagman JSON logs consist of a single JSON object per line,
with no extraneous data. Because all of the data in the file is
pure JSON, with one record per line, these files are easy to parse.
*/
func InitJsonLogger(config *models.Config) (*stdlog.Logger, string) {
processName := path.Base(os.Args[0])
logDir, err := config.EnsureLogDirectory()
if err != nil {
fmt.Fprintf(os.Stderr, "Cannot create log directory '%s': %v\n", logDir, err)
os.Exit(1)
}
filename := fmt.Sprintf("%s.json", processName)
filename = filepath.Join(logDir, filename)
writer, err := os.OpenFile(filename, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0644)
if err != nil {
fmt.Fprintf(os.Stderr, "Cannot open log file '%s': %v", filename, err)
os.Exit(1)
}
return stdlog.New(writer, "", 0), filename
}
/*
InitLogger creates and returns a logger suitable for logging
human-readable message. Also returns the path to the log file.
*/
func InitLogger(config *models.Config) (*logging.Logger, string) {
processName := path.Base(os.Args[0])
logDir, err := config.EnsureLogDirectory()
if err != nil {
fmt.Fprintf(os.Stderr, "Cannot create log directory '%s': %v\n", logDir, err)
os.Exit(1)
}
filename := fmt.Sprintf("%s.log", processName)
filename = filepath.Join(logDir, filename)
if config.LogDirectory != "" {
// If this fails, getRotatingFileWriter will panic in just a second
_ = os.Mkdir(config.LogDirectory, 0755)
}
writer, err := os.OpenFile(filename, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0644)
if err != nil {
fmt.Fprintf(os.Stderr, "Cannot open log file '%s': %v\n", filename, err)
os.Exit(1)
}
log := logging.MustGetLogger(processName)
format := logging.MustStringFormatter("[%{level}] %{message}")
logging.SetFormatter(format)
logging.SetLevel(config.LogLevel, processName)
logBackend := logging.NewLogBackend(writer, "", 0)
if config.LogToStderr {
// Log to BOTH file and stderr
stderrBackend := logging.NewLogBackend(os.Stderr, "", stdlog.LstdFlags|stdlog.Lshortfile)
stderrBackend.Color = true
logging.SetBackend(logBackend, stderrBackend)
} else {
// Log to file only
logging.SetBackend(logBackend)
}
return log, filename
}