circolog/cmd/circolog-tail/main.go
boyska b11c2edfc0 [tail] format locally
JSON is actually unfit to send structured log messages, because
date/time is not well supported. So we are using BSON, which supports
those. BSON is, among the dozen serializers available, really a random
choice and might be changed in the future.
2018-11-11 20:54:10 +01:00

106 rindas
2,4 KiB
Go

package main
import (
"flag"
"fmt"
"log"
"net"
"net/url"
"os"
"os/signal"
"strconv"
"time"
"git.lattuga.net/boyska/circolog/formatter"
"github.com/gorilla/websocket"
"gopkg.in/mcuadros/go-syslog.v2/format"
"gopkg.in/mgo.v2/bson"
)
func main() {
addr := flag.String("addr", "localhost:9080", "http service address")
querySocket := flag.String("socket", "", "Path to a unix domain socket for the HTTP server")
backlogLimit := flag.Int("n", -1, "Limit the backlog length, defaults to no limit (-1)")
flag.Parse()
interrupt := make(chan os.Signal, 1)
signal.Notify(interrupt, os.Interrupt)
var d *websocket.Dialer
u := url.URL{Scheme: "ws",
Host: *addr, // ignored in case of -socket; see the Dialer below
Path: "/ws",
}
q := u.Query()
q.Set("fmt", "bson")
if *backlogLimit >= 0 {
q.Set("l", strconv.Itoa(*backlogLimit))
}
u.RawQuery = q.Encode()
if *querySocket != "" {
d = &websocket.Dialer{
NetDial: func(network, addr string) (net.Conn, error) {
return net.Dial("unix", *querySocket)
},
HandshakeTimeout: 45 * time.Second, // same as DefaultDialer
}
log.Printf("connecting to %s", *querySocket)
} else {
d = websocket.DefaultDialer
log.Printf("connecting to %s", *addr)
}
c, _, err := d.Dial(u.String(), nil)
if err != nil {
log.Fatal("dial:", err)
}
defer c.Close()
log.Println("connected!", u.String())
done := make(chan struct{})
go func() {
defer close(done)
for {
_, serialized, err := c.ReadMessage()
if err != nil {
log.Println("close:", err)
return
}
var parsed format.LogParts
if err := bson.Unmarshal(serialized, &parsed); err != nil {
log.Println("invalid YAML", err)
continue
}
if err := formatter.WriteFormatted(os.Stdout, formatter.FormatSyslog, parsed); err != nil {
log.Println("error printing", err)
}
fmt.Println()
}
}()
for {
select {
case <-done:
return
case <-interrupt:
log.Println("interrupt")
// Cleanly close the connection by sending a close message and then waiting (with timeout) for the
// server to close the connection.
err := c.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, ""))
if err != nil {
log.Println("write close:", err)
return
}
select {
case <-done:
log.Println("Successfully close")
case <-time.After(1 * time.Second):
log.Println("Forced close")
}
return
}
}
}