github.com/projectatomic/docker@v1.8.2/daemon/logger/gelf/gelf.go (about)

     1  // +build linux
     2  
     3  package gelf
     4  
     5  import (
     6  	"bytes"
     7  	"fmt"
     8  	"net"
     9  	"net/url"
    10  	"time"
    11  
    12  	"github.com/Graylog2/go-gelf/gelf"
    13  	"github.com/Sirupsen/logrus"
    14  	"github.com/docker/docker/daemon/logger"
    15  	"github.com/docker/docker/pkg/urlutil"
    16  )
    17  
    18  const name = "gelf"
    19  
    20  type GelfLogger struct {
    21  	writer *gelf.Writer
    22  	ctx    logger.Context
    23  	fields GelfFields
    24  }
    25  
    26  type GelfFields struct {
    27  	hostname      string
    28  	containerId   string
    29  	containerName string
    30  	imageId       string
    31  	imageName     string
    32  	command       string
    33  	tag           string
    34  	created       time.Time
    35  }
    36  
    37  func init() {
    38  	if err := logger.RegisterLogDriver(name, New); err != nil {
    39  		logrus.Fatal(err)
    40  	}
    41  	if err := logger.RegisterLogOptValidator(name, ValidateLogOpt); err != nil {
    42  		logrus.Fatal(err)
    43  	}
    44  }
    45  
    46  func New(ctx logger.Context) (logger.Logger, error) {
    47  	// parse gelf address
    48  	address, err := parseAddress(ctx.Config["gelf-address"])
    49  	if err != nil {
    50  		return nil, err
    51  	}
    52  
    53  	// collect extra data for GELF message
    54  	hostname, err := ctx.Hostname()
    55  	if err != nil {
    56  		return nil, fmt.Errorf("gelf: cannot access hostname to set source field")
    57  	}
    58  
    59  	// remove trailing slash from container name
    60  	containerName := bytes.TrimLeft([]byte(ctx.ContainerName), "/")
    61  
    62  	fields := GelfFields{
    63  		hostname:      hostname,
    64  		containerId:   ctx.ContainerID,
    65  		containerName: string(containerName),
    66  		imageId:       ctx.ContainerImageID,
    67  		imageName:     ctx.ContainerImageName,
    68  		command:       ctx.Command(),
    69  		tag:           ctx.Config["gelf-tag"],
    70  		created:       ctx.ContainerCreated,
    71  	}
    72  
    73  	// create new gelfWriter
    74  	gelfWriter, err := gelf.NewWriter(address)
    75  	if err != nil {
    76  		return nil, fmt.Errorf("gelf: cannot connect to GELF endpoint: %s %v", address, err)
    77  	}
    78  
    79  	return &GelfLogger{
    80  		writer: gelfWriter,
    81  		ctx:    ctx,
    82  		fields: fields,
    83  	}, nil
    84  }
    85  
    86  func (s *GelfLogger) Log(msg *logger.Message) error {
    87  	// remove trailing and leading whitespace
    88  	short := bytes.TrimSpace([]byte(msg.Line))
    89  
    90  	level := gelf.LOG_INFO
    91  	if msg.Source == "stderr" {
    92  		level = gelf.LOG_ERR
    93  	}
    94  
    95  	m := gelf.Message{
    96  		Version:  "1.1",
    97  		Host:     s.fields.hostname,
    98  		Short:    string(short),
    99  		TimeUnix: float64(msg.Timestamp.UnixNano()/int64(time.Millisecond)) / 1000.0,
   100  		Level:    level,
   101  		Extra: map[string]interface{}{
   102  			"_container_id":   s.fields.containerId,
   103  			"_container_name": s.fields.containerName,
   104  			"_image_id":       s.fields.imageId,
   105  			"_image_name":     s.fields.imageName,
   106  			"_command":        s.fields.command,
   107  			"_tag":            s.fields.tag,
   108  			"_created":        s.fields.created,
   109  		},
   110  	}
   111  
   112  	if err := s.writer.WriteMessage(&m); err != nil {
   113  		return fmt.Errorf("gelf: cannot send GELF message: %v", err)
   114  	}
   115  	return nil
   116  }
   117  
   118  func (s *GelfLogger) Close() error {
   119  	return s.writer.Close()
   120  }
   121  
   122  func (s *GelfLogger) Name() string {
   123  	return name
   124  }
   125  
   126  func ValidateLogOpt(cfg map[string]string) error {
   127  	for key := range cfg {
   128  		switch key {
   129  		case "gelf-address":
   130  		case "gelf-tag":
   131  		default:
   132  			return fmt.Errorf("unknown log opt '%s' for gelf log driver", key)
   133  		}
   134  	}
   135  	return nil
   136  }
   137  
   138  func parseAddress(address string) (string, error) {
   139  	if urlutil.IsTransportURL(address) {
   140  		url, err := url.Parse(address)
   141  		if err != nil {
   142  			return "", err
   143  		}
   144  
   145  		// we support only udp
   146  		if url.Scheme != "udp" {
   147  			return "", fmt.Errorf("gelf: endpoint needs to be UDP")
   148  		}
   149  
   150  		// get host and port
   151  		if _, _, err = net.SplitHostPort(url.Host); err != nil {
   152  			return "", fmt.Errorf("gelf: please provide gelf-address as udp://host:port")
   153  		}
   154  
   155  		return url.Host, nil
   156  	}
   157  
   158  	return "", nil
   159  }