syncthing/vendor/github.com/sirupsen/logrus/json_formatter.go
Jakob Borg 916ec63af6 cmd/stdiscosrv: New discovery server (fixes #4618)
This is a new revision of the discovery server. Relevant changes and
non-changes:

- Protocol towards clients is unchanged.

- Recommended large scale design is still to be deployed nehind nginx (I
  tested, and it's still a lot faster at terminating TLS).

- Database backend is leveldb again, only. It scales enough, is easy to
  setup, and we don't need any backend to take care of.

- Server supports replication. This is a simple TCP channel - protect it
  with a firewall when deploying over the internet. (We deploy this within
  the same datacenter, and with firewall.) Any incoming client announces
  are sent over the replication channel(s) to other peer discosrvs.
  Incoming replication changes are applied to the database as if they came
  from clients, but without the TLS/certificate overhead.

- Metrics are exposed using the prometheus library, when enabled.

- The database values and replication protocol is protobuf, because JSON
  was quite CPU intensive when I tried that and benchmarked it.

- The "Retry-After" value for failed lookups gets slowly increased from
  a default of 120 seconds, by 5 seconds for each failed lookup,
  independently by each discosrv. This lowers the query load over time for
  clients that are never seen. The Retry-After maxes out at 3600 after a
  couple of weeks of this increase. The number of failed lookups is
  stored in the database, now and then (avoiding making each lookup a
  database put).

All in all this means clients can be pointed towards a cluster using
just multiple A / AAAA records to gain both load sharing and redundancy
(if one is down, clients will talk to the remaining ones).

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4648
2018-01-14 08:52:31 +00:00

80 lines
1.8 KiB
Go

package logrus
import (
"encoding/json"
"fmt"
)
type fieldKey string
// FieldMap allows customization of the key names for default fields.
type FieldMap map[fieldKey]string
// Default key names for the default fields
const (
FieldKeyMsg = "msg"
FieldKeyLevel = "level"
FieldKeyTime = "time"
)
func (f FieldMap) resolve(key fieldKey) string {
if k, ok := f[key]; ok {
return k
}
return string(key)
}
// JSONFormatter formats logs into parsable json
type JSONFormatter struct {
// TimestampFormat sets the format used for marshaling timestamps.
TimestampFormat string
// DisableTimestamp allows disabling automatic timestamps in output
DisableTimestamp bool
// FieldMap allows users to customize the names of keys for default fields.
// As an example:
// formatter := &JSONFormatter{
// FieldMap: FieldMap{
// FieldKeyTime: "@timestamp",
// FieldKeyLevel: "@level",
// FieldKeyMsg: "@message",
// },
// }
FieldMap FieldMap
}
// Format renders a single log entry
func (f *JSONFormatter) Format(entry *Entry) ([]byte, error) {
data := make(Fields, len(entry.Data)+3)
for k, v := range entry.Data {
switch v := v.(type) {
case error:
// Otherwise errors are ignored by `encoding/json`
// https://github.com/sirupsen/logrus/issues/137
data[k] = v.Error()
default:
data[k] = v
}
}
prefixFieldClashes(data)
timestampFormat := f.TimestampFormat
if timestampFormat == "" {
timestampFormat = defaultTimestampFormat
}
if !f.DisableTimestamp {
data[f.FieldMap.resolve(FieldKeyTime)] = entry.Time.Format(timestampFormat)
}
data[f.FieldMap.resolve(FieldKeyMsg)] = entry.Message
data[f.FieldMap.resolve(FieldKeyLevel)] = entry.Level.String()
serialized, err := json.Marshal(data)
if err != nil {
return nil, fmt.Errorf("Failed to marshal fields to JSON, %v", err)
}
return append(serialized, '\n'), nil
}