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

     1  // +build linux
     2  
     3  package syslog
     4  
     5  import (
     6  	"errors"
     7  	"io"
     8  	"log/syslog"
     9  	"net"
    10  	"net/url"
    11  	"os"
    12  	"path"
    13  	"strconv"
    14  	"strings"
    15  
    16  	"github.com/Sirupsen/logrus"
    17  	"github.com/docker/docker/daemon/logger"
    18  	"github.com/docker/docker/pkg/urlutil"
    19  )
    20  
    21  const name = "syslog"
    22  
    23  var facilities = map[string]syslog.Priority{
    24  	"kern":     syslog.LOG_KERN,
    25  	"user":     syslog.LOG_USER,
    26  	"mail":     syslog.LOG_MAIL,
    27  	"daemon":   syslog.LOG_DAEMON,
    28  	"auth":     syslog.LOG_AUTH,
    29  	"syslog":   syslog.LOG_SYSLOG,
    30  	"lpr":      syslog.LOG_LPR,
    31  	"news":     syslog.LOG_NEWS,
    32  	"uucp":     syslog.LOG_UUCP,
    33  	"cron":     syslog.LOG_CRON,
    34  	"authpriv": syslog.LOG_AUTHPRIV,
    35  	"ftp":      syslog.LOG_FTP,
    36  	"local0":   syslog.LOG_LOCAL0,
    37  	"local1":   syslog.LOG_LOCAL1,
    38  	"local2":   syslog.LOG_LOCAL2,
    39  	"local3":   syslog.LOG_LOCAL3,
    40  	"local4":   syslog.LOG_LOCAL4,
    41  	"local5":   syslog.LOG_LOCAL5,
    42  	"local6":   syslog.LOG_LOCAL6,
    43  	"local7":   syslog.LOG_LOCAL7,
    44  }
    45  
    46  type Syslog struct {
    47  	writer *syslog.Writer
    48  }
    49  
    50  func init() {
    51  	if err := logger.RegisterLogDriver(name, New); err != nil {
    52  		logrus.Fatal(err)
    53  	}
    54  }
    55  
    56  func New(ctx logger.Context) (logger.Logger, error) {
    57  	tag := ctx.Config["syslog-tag"]
    58  	if tag == "" {
    59  		tag = ctx.ContainerID[:12]
    60  	}
    61  
    62  	proto, address, err := parseAddress(ctx.Config["syslog-address"])
    63  	if err != nil {
    64  		return nil, err
    65  	}
    66  
    67  	facility, err := parseFacility(ctx.Config["syslog-facility"])
    68  	if err != nil {
    69  		return nil, err
    70  	}
    71  
    72  	log, err := syslog.Dial(
    73  		proto,
    74  		address,
    75  		facility,
    76  		path.Base(os.Args[0])+"/"+tag,
    77  	)
    78  	if err != nil {
    79  		return nil, err
    80  	}
    81  
    82  	return &Syslog{
    83  		writer: log,
    84  	}, nil
    85  }
    86  
    87  func (s *Syslog) Log(msg *logger.Message) error {
    88  	if msg.Source == "stderr" {
    89  		return s.writer.Err(string(msg.Line))
    90  	}
    91  	return s.writer.Info(string(msg.Line))
    92  }
    93  
    94  func (s *Syslog) Close() error {
    95  	return s.writer.Close()
    96  }
    97  
    98  func (s *Syslog) Name() string {
    99  	return name
   100  }
   101  
   102  func (s *Syslog) GetReader() (io.Reader, error) {
   103  	return nil, logger.ReadLogsNotSupported
   104  }
   105  
   106  func parseAddress(address string) (string, string, error) {
   107  	if urlutil.IsTransportURL(address) {
   108  		url, err := url.Parse(address)
   109  		if err != nil {
   110  			return "", "", err
   111  		}
   112  
   113  		// unix socket validation
   114  		if url.Scheme == "unix" {
   115  			if _, err := os.Stat(url.Path); err != nil {
   116  				return "", "", err
   117  			}
   118  			return url.Scheme, url.Path, nil
   119  		}
   120  
   121  		// here we process tcp|udp
   122  		host := url.Host
   123  		if _, _, err := net.SplitHostPort(host); err != nil {
   124  			if !strings.Contains(err.Error(), "missing port in address") {
   125  				return "", "", err
   126  			}
   127  			host = host + ":514"
   128  		}
   129  
   130  		return url.Scheme, host, nil
   131  	}
   132  
   133  	return "", "", nil
   134  }
   135  
   136  func parseFacility(facility string) (syslog.Priority, error) {
   137  	if facility == "" {
   138  		return syslog.LOG_DAEMON, nil
   139  	}
   140  
   141  	if syslogFacility, valid := facilities[facility]; valid {
   142  		return syslogFacility, nil
   143  	}
   144  
   145  	fInt, err := strconv.Atoi(facility)
   146  	if err == nil && 0 <= fInt && fInt <= 23 {
   147  		return syslog.Priority(fInt << 3), nil
   148  	}
   149  
   150  	return syslog.Priority(0), errors.New("invalid syslog facility")
   151  }