circolog/cmd/circologd/http.go

122 lines
2.8 KiB
Go

package main
import (
"errors"
"log"
"net/http"
"strconv"
"time"
"git.lattuga.net/boyska/circolog"
"github.com/gorilla/websocket"
"gopkg.in/mcuadros/go-syslog.v2/format"
)
type requestParams struct {
// Add here the expected request parameters
errorList map[string]error
requestMessageLen int
}
func setupHTTP(hub circolog.Hub) {
http.HandleFunc("/", getHTTPHandler(hub))
http.HandleFunc("/ws", getWSHandler(hub))
}
func parseParameterL(r *http.Request) (int, error) {
var requestMessageLen int
var err error
if reqL, ok := r.Form["l"]; ok {
if len(reqL) == 1 {
requestMessageLen, err = strconv.Atoi(reqL[0])
if err != nil {
return 0, err
}
if requestMessageLen <= 0 {
return 0, errors.New("malformed request")
}
} else {
return 0, errors.New("malformed request")
}
}
return requestMessageLen, nil
}
func (p *requestParams) parseParameters(w http.ResponseWriter, r *http.Request) {
err := r.ParseForm()
if err != nil {
log.Println("error parsing http request", err)
}
p.errorList = make(map[string]error, 1)
p.requestMessageLen, p.errorList["l"] = parseParameterL(r)
}
func getHTTPHandler(hub circolog.Hub) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
// Looking for known parameter in the request
var params requestParams
params.parseParameters(w, r)
if params.errorList["l"] != nil {
log.Println("Request parameter \"l\":", params.errorList["l"])
w.WriteHeader(400)
return
}
client := circolog.Client{
Messages: make(chan format.LogParts, 20),
LastMsg: params.requestMessageLen,
Nofollow: true}
hub.Register <- client
for x := range client.Messages {
w.Write([]byte(circolog.FormatSyslog(x)))
w.Write([]byte("\n"))
}
}
}
func getWSHandler(hub circolog.Hub) http.HandlerFunc {
var upgrader = websocket.Upgrader{
ReadBufferSize: 1024,
WriteBufferSize: 1024,
}
return func(w http.ResponseWriter, r *http.Request) {
conn, err := upgrader.Upgrade(w, r, nil)
if err != nil {
return
}
client := circolog.Client{Messages: make(chan format.LogParts, 20)}
hub.Register <- client
// Allow collection of memory referenced by the caller by doing all work in
// new goroutines.
go func(conn *websocket.Conn, c circolog.Client) {
defer func() {
hub.Unregister <- c
conn.Close()
}()
for {
select {
case message, ok := <-c.Messages:
conn.SetWriteDeadline(time.Now().Add(10 * time.Second))
if !ok {
// The hub closed the channel.
conn.WriteMessage(websocket.CloseMessage, []byte{})
return
}
w, err := conn.NextWriter(websocket.TextMessage)
if err != nil {
return
}
w.Write([]byte(circolog.FormatSyslog(message)))
if err := w.Close(); err != nil {
return
}
// TODO: ticker/ping
}
}
}(conn, client)
}
}