coredns/middleware/log/log.go
Miek Gieben 050eccd69e mw/logs: add rflags to logging (#845)
Add the DNS message response flags as {rflags} to the default logging
Also complete the replacer testing that is was commented out.
And (unrelated) Switch erratic and whoami to ease testing.

Note: {flags} could and should be added as well - but we can leave that
as a beginners bug.
2017-08-07 03:49:40 -07:00

91 lines
2.7 KiB
Go

// Package log implements basic but useful request (access) logging middleware.
package log
import (
"log"
"time"
"github.com/coredns/coredns/middleware"
"github.com/coredns/coredns/middleware/metrics/vars"
"github.com/coredns/coredns/middleware/pkg/dnsrecorder"
"github.com/coredns/coredns/middleware/pkg/rcode"
"github.com/coredns/coredns/middleware/pkg/replacer"
"github.com/coredns/coredns/middleware/pkg/response"
"github.com/coredns/coredns/request"
"github.com/miekg/dns"
"golang.org/x/net/context"
)
// Logger is a basic request logging middleware.
type Logger struct {
Next middleware.Handler
Rules []Rule
ErrorFunc func(dns.ResponseWriter, *dns.Msg, int) // failover error handler
}
// ServeDNS implements the middleware.Handler interface.
func (l Logger) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
state := request.Request{W: w, Req: r}
for _, rule := range l.Rules {
if !middleware.Name(rule.NameScope).Matches(state.Name()) {
continue
}
rrw := dnsrecorder.New(w)
rc, err := middleware.NextOrFailure(l.Name(), l.Next, ctx, rrw, r)
if rc > 0 {
// There was an error up the chain, but no response has been written yet.
// The error must be handled here so the log entry will record the response size.
if l.ErrorFunc != nil {
l.ErrorFunc(rrw, r, rc)
} else {
answer := new(dns.Msg)
answer.SetRcode(r, rc)
state.SizeAndDo(answer)
vars.Report(state, vars.Dropped, rcode.ToString(rc), answer.Len(), time.Now())
w.WriteMsg(answer)
}
rc = 0
}
tpe, _ := response.Typify(rrw.Msg, time.Now().UTC())
class := response.Classify(tpe)
if rule.Class == response.All || rule.Class == class {
rep := replacer.New(r, rrw, CommonLogEmptyValue)
rule.Log.Println(rep.Replace(rule.Format))
}
return rc, err
}
return middleware.NextOrFailure(l.Name(), l.Next, ctx, w, r)
}
// Name implements the Handler interface.
func (l Logger) Name() string { return "log" }
// Rule configures the logging middleware.
type Rule struct {
NameScope string
Class response.Class
OutputFile string
Format string
Log *log.Logger
}
const (
// DefaultLogFilename is the default output name. This is the only supported value.
DefaultLogFilename = "stdout"
// CommonLogFormat is the common log format.
CommonLogFormat = `{remote} ` + CommonLogEmptyValue + ` [{when}] "{type} {class} {name} {proto} {size} {>do} {>bufsize}" {rcode} {>rflags} {rsize} {duration}`
// CommonLogEmptyValue is the common empty log value.
CommonLogEmptyValue = "-"
// CombinedLogFormat is the combined log format.
CombinedLogFormat = CommonLogFormat + ` "{>opcode}"`
// DefaultLogFormat is the default log format.
DefaultLogFormat = CommonLogFormat
)