github.com/chenchun/docker@v1.3.2-0.20150629222414-20467faf132b/daemon/logger/gelf/gelf.go (about)

     1  // +build linux
     2  
     3  package gelf
     4  
     5  import (
     6  	"bytes"
     7  	"fmt"
     8  	"io"
     9  	"net"
    10  	"net/url"
    11  	"time"
    12  
    13  	"github.com/Graylog2/go-gelf/gelf"
    14  	"github.com/Sirupsen/logrus"
    15  	"github.com/docker/docker/daemon/logger"
    16  	"github.com/docker/docker/pkg/urlutil"
    17  )
    18  
    19  const name = "gelf"
    20  
    21  type GelfLogger struct {
    22  	writer *gelf.Writer
    23  	ctx    logger.Context
    24  	fields GelfFields
    25  }
    26  
    27  type GelfFields struct {
    28  	hostname      string
    29  	containerId   string
    30  	containerName string
    31  	imageId       string
    32  	imageName     string
    33  	command       string
    34  	tag           string
    35  	created       time.Time
    36  }
    37  
    38  func init() {
    39  	if err := logger.RegisterLogDriver(name, New); err != nil {
    40  		logrus.Fatal(err)
    41  	}
    42  }
    43  
    44  func New(ctx logger.Context) (logger.Logger, error) {
    45  	// parse gelf address
    46  	address, err := parseAddress(ctx.Config["gelf-address"])
    47  	if err != nil {
    48  		return nil, err
    49  	}
    50  
    51  	// collect extra data for GELF message
    52  	hostname, err := ctx.Hostname()
    53  	if err != nil {
    54  		return nil, fmt.Errorf("gelf: cannot access hostname to set source field")
    55  	}
    56  
    57  	// remove trailing slash from container name
    58  	containerName := bytes.TrimLeft([]byte(ctx.ContainerName), "/")
    59  
    60  	fields := GelfFields{
    61  		hostname:      hostname,
    62  		containerId:   ctx.ContainerID,
    63  		containerName: string(containerName),
    64  		imageId:       ctx.ContainerImageID,
    65  		imageName:     ctx.ContainerImageName,
    66  		command:       ctx.Command(),
    67  		tag:           ctx.Config["gelf-tag"],
    68  		created:       ctx.ContainerCreated,
    69  	}
    70  
    71  	// create new gelfWriter
    72  	gelfWriter, err := gelf.NewWriter(address)
    73  	if err != nil {
    74  		return nil, fmt.Errorf("gelf: cannot connect to GELF endpoint: %s %v", address, err)
    75  	}
    76  
    77  	return &GelfLogger{
    78  		writer: gelfWriter,
    79  		ctx:    ctx,
    80  		fields: fields,
    81  	}, nil
    82  }
    83  
    84  func (s *GelfLogger) Log(msg *logger.Message) error {
    85  	// remove trailing and leading whitespace
    86  	short := bytes.TrimSpace([]byte(msg.Line))
    87  
    88  	level := gelf.LOG_INFO
    89  	if msg.Source == "stderr" {
    90  		level = gelf.LOG_ERR
    91  	}
    92  
    93  	m := gelf.Message{
    94  		Version:  "1.1",
    95  		Host:     s.fields.hostname,
    96  		Short:    string(short),
    97  		TimeUnix: float64(msg.Timestamp.UnixNano()/int64(time.Millisecond)) / 1000.0,
    98  		Level:    level,
    99  		Extra: map[string]interface{}{
   100  			"_container_id":   s.fields.containerId,
   101  			"_container_name": s.fields.containerName,
   102  			"_image_id":       s.fields.imageId,
   103  			"_image_name":     s.fields.imageName,
   104  			"_command":        s.fields.command,
   105  			"_tag":            s.fields.tag,
   106  			"_created":        s.fields.created,
   107  		},
   108  	}
   109  
   110  	if err := s.writer.WriteMessage(&m); err != nil {
   111  		return fmt.Errorf("gelf: cannot send GELF message: %v", err)
   112  	}
   113  	return nil
   114  }
   115  
   116  func (s *GelfLogger) GetReader() (io.Reader, error) {
   117  	return nil, logger.ReadLogsNotSupported
   118  }
   119  
   120  func (s *GelfLogger) Close() error {
   121  	return s.writer.Close()
   122  }
   123  
   124  func (s *GelfLogger) Name() string {
   125  	return name
   126  }
   127  
   128  func parseAddress(address string) (string, error) {
   129  	if urlutil.IsTransportURL(address) {
   130  		url, err := url.Parse(address)
   131  		if err != nil {
   132  			return "", err
   133  		}
   134  
   135  		// we support only udp
   136  		if url.Scheme != "udp" {
   137  			return "", fmt.Errorf("gelf: endpoint needs to be UDP")
   138  		}
   139  
   140  		// get host and port
   141  		if _, _, err = net.SplitHostPort(url.Host); err != nil {
   142  			return "", fmt.Errorf("gelf: please provide gelf-address as udp://host:port")
   143  		}
   144  
   145  		return url.Host, nil
   146  	}
   147  
   148  	return "", nil
   149  }