windows_exporter/internal/log/logger.go

70 lines
1.4 KiB
Go

package log
import (
"errors"
"fmt"
"io"
"log/slog"
"os"
"github.com/prometheus-community/windows_exporter/internal/log/eventlog"
"github.com/prometheus/common/promslog"
"golang.org/x/sys/windows"
)
// AllowedFile is a settable identifier for the output file that the logger can have.
type AllowedFile struct {
s string
w io.Writer
}
func (f *AllowedFile) String() string {
return f.s
}
// Set updates the value of the allowed format.
func (f *AllowedFile) Set(s string) error {
f.s = s
switch s {
case "stdout":
f.w = os.Stdout
case "stderr":
f.w = os.Stderr
case "eventlog":
handle, err := windows.RegisterEventSource(nil, windows.StringToUTF16Ptr("windows_exporter"))
if err != nil {
return fmt.Errorf("failed to open event log: %w", err)
}
f.w = eventlog.NewEventLogWriter(handle)
default:
file, err := os.OpenFile(s, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0o200)
if err != nil {
return fmt.Errorf("failed to open log file: %w", err)
}
f.w = file
}
return nil
}
// Config is a struct containing configurable settings for the logger.
type Config struct {
*promslog.Config
File *AllowedFile
}
func New(config *Config) (*slog.Logger, error) {
if config.File == nil {
return nil, errors.New("log file undefined")
}
config.Config.Writer = config.File.w
config.Config.Style = promslog.GoKitStyle
return promslog.New(config.Config), nil
}