yanic/respond/collector.go

173 lines
3.7 KiB
Go

package respond
import (
"bytes"
"compress/flate"
"encoding/json"
"log"
"net"
"reflect"
"time"
"github.com/FreifunkBremen/respond-collector/data"
"github.com/FreifunkBremen/respond-collector/database"
"github.com/FreifunkBremen/respond-collector/models"
)
//Collector for a specificle respond messages
type Collector struct {
CollectType string
connection *net.UDPConn // UDP socket
queue chan *Response // received responses
msgType reflect.Type
multicastAddr string
db *database.DB
nodes *models.Nodes
// Ticker and stopper
ticker *time.Ticker
stop chan interface{}
}
// Creates a Collector struct
func NewCollector(db *database.DB, nodes *models.Nodes, interval time.Duration, iface string) *Collector {
// Parse address
addr, err := net.ResolveUDPAddr("udp", "[::]:0")
if err != nil {
log.Panic(err)
}
// Open socket
conn, err := net.ListenUDP("udp", addr)
if err != nil {
log.Panic(err)
}
conn.SetReadBuffer(maxDataGramSize)
collector := &Collector{
connection: conn,
db: db,
nodes: nodes,
multicastAddr: net.JoinHostPort(multiCastGroup+"%"+iface, port),
queue: make(chan *Response, 400),
ticker: time.NewTicker(interval),
stop: make(chan interface{}, 1),
}
go collector.receiver()
go collector.parser()
// Run senders
go func() {
collector.sendOnce() // immediately
collector.sender() // periodically
}()
return collector
}
// Close Collector
func (coll *Collector) Close() {
// stop ticker
coll.ticker.Stop()
close(coll.stop)
coll.connection.Close()
close(coll.queue)
}
func (coll *Collector) sendOnce() {
coll.sendPacket(coll.multicastAddr)
}
func (coll *Collector) sendPacket(address string) {
addr, err := net.ResolveUDPAddr("udp", address)
if err != nil {
log.Panic(err)
}
if _, err := coll.connection.WriteToUDP([]byte("GET nodeinfo statistics neighbours"), addr); err != nil {
log.Println("WriteToUDP failed:", err)
}
}
// send packets continously
func (coll *Collector) sender() {
for {
select {
case <-coll.stop:
return
case <-coll.ticker.C:
// save global statistics
coll.db.AddPoint(database.MeasurementGlobal, nil, coll.nodes.GlobalStats().Fields(), time.Now())
// send the multicast packet to request per-node statistics
coll.sendOnce()
}
}
}
func (coll *Collector) parser() {
for obj := range coll.queue {
if data, err := obj.parse(); err != nil {
log.Println("unable to decode response from", obj.Address.String(), err, "\n", string(obj.Raw))
} else {
coll.saveResponse(obj.Address, data)
}
}
}
func (res *Response) parse() (*data.ResponseData, error) {
// Deflate
deflater := flate.NewReader(bytes.NewReader(res.Raw))
defer deflater.Close()
// Unmarshal
rdata := &data.ResponseData{}
err := json.NewDecoder(deflater).Decode(rdata)
return rdata, err
}
func (coll *Collector) saveResponse(addr net.UDPAddr, res *data.ResponseData) {
// Search for NodeID
var nodeId string
if val := res.NodeInfo; val != nil {
nodeId = val.NodeId
} else if val := res.Neighbours; val != nil {
nodeId = val.NodeId
} else if val := res.Statistics; val != nil {
nodeId = val.NodeId
}
// Updates nodes if NodeID found
if len(nodeId) != 12 {
log.Printf("invalid NodeID '%s' from %s", nodeId, addr.String())
return
}
node := coll.nodes.Update(nodeId, res)
if coll.db != nil && node.Statistics != nil {
coll.db.Add(nodeId, node)
}
}
func (coll *Collector) receiver() {
buf := make([]byte, maxDataGramSize)
for {
n, src, err := coll.connection.ReadFromUDP(buf)
if err != nil {
log.Println("ReadFromUDP failed:", err)
return
}
raw := make([]byte, n)
copy(raw, buf)
coll.queue <- &Response{
Address: *src,
Raw: raw,
}
}
}