/
gelf.go
149 lines (124 loc) · 3.21 KB
/
gelf.go
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// +build linux
package gelf
import (
"bytes"
"fmt"
"io"
"net"
"net/url"
"time"
"github.com/Graylog2/go-gelf/gelf"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/daemon/logger"
"github.com/docker/docker/pkg/urlutil"
)
const name = "gelf"
type GelfLogger struct {
writer *gelf.Writer
ctx logger.Context
fields GelfFields
}
type GelfFields struct {
hostname string
containerId string
containerName string
imageId string
imageName string
command string
tag string
created time.Time
}
func init() {
if err := logger.RegisterLogDriver(name, New); err != nil {
logrus.Fatal(err)
}
}
func New(ctx logger.Context) (logger.Logger, error) {
// parse gelf address
address, err := parseAddress(ctx.Config["gelf-address"])
if err != nil {
return nil, err
}
// collect extra data for GELF message
hostname, err := ctx.Hostname()
if err != nil {
return nil, fmt.Errorf("gelf: cannot access hostname to set source field")
}
// remove trailing slash from container name
containerName := bytes.TrimLeft([]byte(ctx.ContainerName), "/")
fields := GelfFields{
hostname: hostname,
containerId: ctx.ContainerID,
containerName: string(containerName),
imageId: ctx.ContainerImageID,
imageName: ctx.ContainerImageName,
command: ctx.Command(),
tag: ctx.Config["gelf-tag"],
created: ctx.ContainerCreated,
}
// create new gelfWriter
gelfWriter, err := gelf.NewWriter(address)
if err != nil {
return nil, fmt.Errorf("gelf: cannot connect to GELF endpoint: %s %v", address, err)
}
return &GelfLogger{
writer: gelfWriter,
ctx: ctx,
fields: fields,
}, nil
}
func (s *GelfLogger) Log(msg *logger.Message) error {
// remove trailing and leading whitespace
short := bytes.TrimSpace([]byte(msg.Line))
level := gelf.LOG_INFO
if msg.Source == "stderr" {
level = gelf.LOG_ERR
}
m := gelf.Message{
Version: "1.1",
Host: s.fields.hostname,
Short: string(short),
TimeUnix: float64(msg.Timestamp.UnixNano()/int64(time.Millisecond)) / 1000.0,
Level: level,
Extra: map[string]interface{}{
"_container_id": s.fields.containerId,
"_container_name": s.fields.containerName,
"_image_id": s.fields.imageId,
"_image_name": s.fields.imageName,
"_command": s.fields.command,
"_tag": s.fields.tag,
"_created": s.fields.created,
},
}
if err := s.writer.WriteMessage(&m); err != nil {
return fmt.Errorf("gelf: cannot send GELF message: %v", err)
}
return nil
}
func (s *GelfLogger) GetReader() (io.Reader, error) {
return nil, logger.ReadLogsNotSupported
}
func (s *GelfLogger) Close() error {
return s.writer.Close()
}
func (s *GelfLogger) Name() string {
return name
}
func parseAddress(address string) (string, error) {
if urlutil.IsTransportURL(address) {
url, err := url.Parse(address)
if err != nil {
return "", err
}
// we support only udp
if url.Scheme != "udp" {
return "", fmt.Errorf("gelf: endpoint needs to be UDP")
}
// get host and port
if _, _, err = net.SplitHostPort(url.Host); err != nil {
return "", fmt.Errorf("gelf: please provide gelf-address as udp://host:port")
}
return url.Host, nil
}
return "", nil
}