cc-metric-collector/sinks/natsSink.go
2022-02-23 14:56:29 +01:00

112 lines
2.7 KiB
Go

package sinks
import (
"bytes"
"encoding/json"
"errors"
"fmt"
"time"
cclog "github.com/ClusterCockpit/cc-metric-collector/internal/ccLogger"
lp "github.com/ClusterCockpit/cc-metric-collector/internal/ccMetric"
influx "github.com/influxdata/line-protocol"
nats "github.com/nats-io/nats.go"
)
type NatsSinkConfig struct {
defaultSinkConfig
Host string `json:"host,omitempty"`
Port string `json:"port,omitempty"`
Database string `json:"database,omitempty"`
User string `json:"user,omitempty"`
Password string `json:"password,omitempty"`
}
type NatsSink struct {
sink
client *nats.Conn
encoder *influx.Encoder
buffer *bytes.Buffer
config NatsSinkConfig
}
func (s *NatsSink) connect() error {
var err error
var uinfo nats.Option = nil
var nc *nats.Conn
if len(s.config.User) > 0 && len(s.config.Password) > 0 {
uinfo = nats.UserInfo(s.config.User, s.config.Password)
}
uri := fmt.Sprintf("nats://%s:%s", s.config.Host, s.config.Port)
cclog.ComponentDebug(s.name, "Connect to", uri)
s.client = nil
if uinfo != nil {
nc, err = nats.Connect(uri, uinfo)
} else {
nc, err = nats.Connect(uri)
}
if err != nil {
cclog.ComponentError(s.name, "Connect to", uri, "failed:", err.Error())
return err
}
s.client = nc
return nil
}
func (s *NatsSink) Write(m lp.CCMetric) error {
if s.client != nil {
_, err := s.encoder.Encode(m.ToPoint(s.config.MetaAsTags))
if err != nil {
cclog.ComponentError(s.name, "Write:", err.Error())
return err
}
}
return nil
}
func (s *NatsSink) Flush() error {
if s.client != nil {
if err := s.client.Publish(s.config.Database, s.buffer.Bytes()); err != nil {
cclog.ComponentError(s.name, "Flush:", err.Error())
return err
}
s.buffer.Reset()
}
return nil
}
func (s *NatsSink) Close() {
if s.client != nil {
cclog.ComponentDebug(s.name, "Close")
s.client.Close()
}
}
func NewNatsSink(name string, config json.RawMessage) (Sink, error) {
s := new(NatsSink)
s.name = fmt.Sprintf("NatsSink(%s)", name)
if len(config) > 0 {
err := json.Unmarshal(config, &s.config)
if err != nil {
cclog.ComponentError(s.name, "Error reading config for", s.name, ":", err.Error())
return nil, err
}
}
if len(s.config.Host) == 0 ||
len(s.config.Port) == 0 ||
len(s.config.Database) == 0 {
return nil, errors.New("not all configuration variables set required by NatsSink")
}
// Setup Influx line protocol
s.buffer = &bytes.Buffer{}
s.buffer.Grow(1025)
s.encoder = influx.NewEncoder(s.buffer)
s.encoder.SetPrecision(time.Second)
s.encoder.SetMaxLineBytes(1024)
// Setup infos for connection
if err := s.connect(); err != nil {
return nil, fmt.Errorf("Unable to connect: %v", err)
}
return s, nil
}