prometheus/pkg/logging/file.go

63 lines
1.6 KiB
Go

// Copyright 2020 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package logging
import (
"os"
"time"
"github.com/go-kit/kit/log"
"github.com/pkg/errors"
)
var (
timestampFormat = log.TimestampFormat(
func() time.Time { return time.Now().UTC() },
"2006-01-02T15:04:05.000Z07:00",
)
)
// JSONFileLogger represents a logger that writes JSON to a file.
type JSONFileLogger struct {
logger log.Logger
file *os.File
}
// NewJSONFileLogger returns a new JSONFileLogger.
func NewJSONFileLogger(s string) (*JSONFileLogger, error) {
if s == "" {
return nil, nil
}
f, err := os.OpenFile(s, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0666)
if err != nil {
return nil, errors.Wrap(err, "can't create json logger")
}
return &JSONFileLogger{
logger: log.With(log.NewJSONLogger(f), "ts", timestampFormat),
file: f,
}, nil
}
// Close closes the underlying file.
func (l *JSONFileLogger) Close() error {
return l.file.Close()
}
// Log calls the Log function of the underlying logger.
func (l *JSONFileLogger) Log(i ...interface{}) error {
return l.logger.Log(i...)
}