-
-
Notifications
You must be signed in to change notification settings - Fork 198
/
query_logging_resolver.go
235 lines (192 loc) · 5.95 KB
/
query_logging_resolver.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
package resolver
import (
"blocky/config"
"blocky/util"
"encoding/csv"
"fmt"
"io"
"io/ioutil"
"os"
"path/filepath"
"regexp"
"strings"
"time"
"github.com/miekg/dns"
"github.com/sirupsen/logrus"
"golang.org/x/sys/unix"
)
const (
cleanUpRunPeriod = 12 * time.Hour
queryLoggingResolverPrefix = "query_logging_resolver"
logChanCap = 1000
)
// QueryLoggingResolver writes query information (question, answer, duration, ...) into
// log file or as log entry (if log directory is not configured)
type QueryLoggingResolver struct {
NextResolver
logDir string
perClient bool
logRetentionDays uint64
logChan chan *queryLogEntry
}
type queryLogEntry struct {
request *Request
response *Response
start time.Time
durationMs int64
logger *logrus.Entry
}
func NewQueryLoggingResolver(cfg config.QueryLogConfig) ChainedResolver {
if cfg.Dir != "" && unix.Access(cfg.Dir, unix.W_OK) != nil {
logger(queryLoggingResolverPrefix).Fatalf("query log directory '%s' does not exist or is not writable", cfg.Dir)
}
logChan := make(chan *queryLogEntry, logChanCap)
resolver := QueryLoggingResolver{
logDir: cfg.Dir,
perClient: cfg.PerClient,
logRetentionDays: cfg.LogRetentionDays,
logChan: logChan,
}
go resolver.writeLog()
if cfg.LogRetentionDays > 0 {
go resolver.periodicCleanUp()
}
return &resolver
}
// triggers periodically cleanup of old log files
func (r *QueryLoggingResolver) periodicCleanUp() {
ticker := time.NewTicker(cleanUpRunPeriod)
defer ticker.Stop()
for {
<-ticker.C
r.doCleanUp()
}
}
// deletes old log files
func (r *QueryLoggingResolver) doCleanUp() {
logger := logger(queryLoggingResolverPrefix)
logger.Trace("starting clean up")
files, err := ioutil.ReadDir(r.logDir)
if err != nil {
logger.WithField("log_dir", r.logDir).Error("can't list log directory: ", err)
}
// search for log files, which names starts with date
for _, f := range files {
if strings.HasSuffix(f.Name(), ".log") && len(f.Name()) > 10 {
t, err := time.Parse("2006-01-02", f.Name()[:10])
if err == nil {
differenceDays := uint64(time.Since(t).Hours() / 24)
if r.logRetentionDays > 0 && differenceDays > r.logRetentionDays {
logger.WithFields(logrus.Fields{
"file": f.Name(),
"ageInDays": differenceDays,
"logRetentionDays": r.logRetentionDays,
}).Info("existing log file is older than retention time and will be deleted")
err := os.Remove(filepath.Join(r.logDir, f.Name()))
if err != nil {
logger.WithField("file", f.Name()).Error("can't remove file: ", err)
}
}
}
}
}
}
func (r *QueryLoggingResolver) Resolve(request *Request) (*Response, error) {
logger := withPrefix(request.Log, queryLoggingResolverPrefix)
start := time.Now()
resp, err := r.next.Resolve(request)
duration := time.Since(start).Milliseconds()
if err == nil {
select {
case r.logChan <- &queryLogEntry{
request: request,
response: resp,
start: start,
durationMs: duration,
logger: logger}:
default:
logger.Error("query log writer is too slow, log entry will be dropped")
}
}
return resp, err
}
// write entry: if log directory is configured, write to log file
func (r *QueryLoggingResolver) writeLog() {
for logEntry := range r.logChan {
if r.logDir != "" {
var clientPrefix string
start := time.Now()
dateString := logEntry.start.Format("2006-01-02")
if r.perClient {
clientPrefix = strings.Join(logEntry.request.ClientNames, "-")
} else {
clientPrefix = "ALL"
}
fileName := fmt.Sprintf("%s_%s.log", dateString, escape(clientPrefix))
writePath := filepath.Join(r.logDir, fileName)
file, err := os.OpenFile(writePath, os.O_APPEND|os.O_CREATE|os.O_RDWR, 0666)
if err != nil {
logEntry.logger.WithField("file_name", writePath).Error("can't create/open file", err)
} else {
writer := createCsvWriter(file)
err := writer.Write(createQueryLogRow(logEntry))
if err != nil {
logEntry.logger.WithField("file_name", writePath).Error("can't write to file", err)
}
writer.Flush()
_ = file.Close()
}
halfCap := cap(r.logChan) / 2
// if log channel is > 50% full, this could be a problem with slow writer (external storage over network etc.)
if len(r.logChan) > halfCap {
logEntry.logger.WithField("channel_len",
len(r.logChan)).Warnf("query log writer is too slow, write duration: %d ms", time.Since(start).Milliseconds())
}
} else {
logEntry.logger.WithFields(
logrus.Fields{
"response_reason": logEntry.response.Reason,
"response_code": dns.RcodeToString[logEntry.response.Res.Rcode],
"answer": util.AnswerToString(logEntry.response.Res.Answer),
"duration_ms": logEntry.durationMs,
},
).Infof("query resolved")
}
}
}
func escape(file string) string {
reg := regexp.MustCompile("[^a-zA-Z0-9-_]+")
return reg.ReplaceAllString(file, "_")
}
func createCsvWriter(file io.Writer) *csv.Writer {
writer := csv.NewWriter(file)
writer.Comma = '\t'
return writer
}
func createQueryLogRow(logEntry *queryLogEntry) []string {
request := logEntry.request
response := logEntry.response
return []string{
logEntry.start.Format("2006-01-02 15:04:05"),
request.ClientIP.String(),
strings.Join(request.ClientNames, "; "),
fmt.Sprintf("%d", logEntry.durationMs),
response.Reason,
util.QuestionToString(request.Req.Question),
util.AnswerToString(response.Res.Answer),
dns.RcodeToString[response.Res.Rcode],
}
}
func (r *QueryLoggingResolver) Configuration() (result []string) {
if r.logDir != "" {
result = append(result, fmt.Sprintf("logDir= \"%s\"", r.logDir))
result = append(result, fmt.Sprintf("perClient = %t", r.perClient))
result = append(result, fmt.Sprintf("logRetentionDays= %d", r.logRetentionDays))
if r.logRetentionDays == 0 {
result = append(result, "log cleanup deactivated")
}
} else {
result = []string{"deactivated"}
}
return
}