minio/cmd/notify-kafka.go
Krishna Srinivas 14e6c5ec08 Simplify the steps to make changes to config.json (#5186)
This change introduces following simplified steps to follow 
during config migration.

```
 // Steps to move from version N to version N+1
 // 1. Add new struct serverConfigVN+1 in config-versions.go
 // 2. Set configCurrentVersion to "N+1"
 // 3. Set serverConfigCurrent to serverConfigVN+1
 // 4. Add new migration function (ex. func migrateVNToVN+1()) in config-migrate.go
 // 5. Call migrateVNToVN+1() from migrateConfig() in config-migrate.go
 // 6. Make changes in config-current_test.go for any test change
```
2017-11-29 13:12:47 -08:00

151 lines
3.6 KiB
Go

/*
* Minio Cloud Storage, (C) 2014-2016 Minio, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package cmd
import (
"io/ioutil"
"net"
"github.com/Sirupsen/logrus"
sarama "gopkg.in/Shopify/sarama.v1"
)
var (
kkErrFunc = newNotificationErrorFactory("Kafka")
)
// kafkaNotify holds the configuration of the Kafka server/cluster to
// send notifications to.
type kafkaNotify struct {
// Flag to enable/disable this notification from configuration
// file.
Enable bool `json:"enable"`
// List of Kafka brokers in `addr:host` format.
Brokers []string `json:"brokers"`
// Topic to which event notifications should be sent.
Topic string `json:"topic"`
}
func (k *kafkaNotify) Validate() error {
if !k.Enable {
return nil
}
if len(k.Brokers) == 0 {
return kkErrFunc("No broker(s) specified.")
}
// Validate all specified brokers.
for _, brokerAddr := range k.Brokers {
if _, _, err := net.SplitHostPort(brokerAddr); err != nil {
return err
}
}
return nil
}
// kafkaConn contains the active connection to the Kafka cluster and
// the topic to send event notifications to.
type kafkaConn struct {
producer sarama.SyncProducer
topic string
}
func dialKafka(kn kafkaNotify) (kc kafkaConn, e error) {
if !kn.Enable {
return kc, errNotifyNotEnabled
}
if kn.Topic == "" {
return kc, kkErrFunc(
"Topic was not specified in configuration")
}
config := sarama.NewConfig()
// Wait for all in-sync replicas to ack the message
config.Producer.RequiredAcks = sarama.WaitForAll
// Retry up to 10 times to produce the message
config.Producer.Retry.Max = 10
config.Producer.Return.Successes = true
p, err := sarama.NewSyncProducer(kn.Brokers, config)
if err != nil {
return kc, kkErrFunc("Failed to start producer: %v", err)
}
return kafkaConn{p, kn.Topic}, nil
}
func newKafkaNotify(accountID string) (*logrus.Logger, error) {
kafkaNotifyCfg := globalServerConfig.Notify.GetKafkaByID(accountID)
// Try connecting to the configured Kafka broker(s).
kc, err := dialKafka(kafkaNotifyCfg)
if err != nil {
return nil, err
}
// Configure kafkaConn object as a Hook in logrus.
kafkaLog := logrus.New()
kafkaLog.Out = ioutil.Discard
kafkaLog.Formatter = new(logrus.JSONFormatter)
kafkaLog.Hooks.Add(kc)
return kafkaLog, nil
}
func (kC kafkaConn) Close() {
_ = kC.producer.Close()
}
// Fire - to implement logrus.Hook interface
func (kC kafkaConn) Fire(entry *logrus.Entry) error {
body, err := entry.Reader()
if err != nil {
return err
}
// Extract the key of the event as a string
keyStr, ok := entry.Data["Key"].(string)
if !ok {
return kkErrFunc("Unable to convert event key %v to string.",
entry.Data["Key"])
}
// Construct message to send to Kafka
msg := sarama.ProducerMessage{
Topic: kC.topic,
Key: sarama.StringEncoder(keyStr),
Value: sarama.ByteEncoder(body.Bytes()),
}
// Attempt sending the message to Kafka
_, _, err = kC.producer.SendMessage(&msg)
if err != nil {
return kkErrFunc("Error sending event to Kafka - %v", err)
}
return nil
}
// Levels - to implement logrus.Hook interface
func (kC kafkaConn) Levels() []logrus.Level {
return []logrus.Level{
logrus.InfoLevel,
}
}