HTTP Callback
服务器端定制的实现方式，就是HTTP回调。譬如当客户端连接到SRS时，回调指定的http地址，这样可以实现验证功能。
关于Token认证，即基于http回调的认证，参考：Token Authentication
Compile
SRS总是开启HttpCallback。
参考：Build
Config SRS
http hooks的配置如下：
vhost your_vhost {
http_hooks {
# whether the http hooks enable.
# default off.
enabled on;
# when client(encoder) publish to vhost/app/stream, call the hook,
# the request in the POST data string is a object encode by json:
# {
# "action": "on_publish",
# "client_id": "9308h583",
# "ip": "192.168.1.10", "vhost": "video.test.com", "app": "live",
# "stream": "livestream", "param":"?token=xxx&salt=yyy"
# }
# if valid, the hook must return HTTP code 200(Status OK) and response
# an int value specifies the error code(0 corresponding to success):
# 0
# support multiple api hooks, format:
# on_publish http://xxx/api0 http://xxx/api1 http://xxx/apiN
# @remark For SRS4, the HTTPS url is supported, for example:
# on_publish https://xxx/api0 https://xxx/api1 https://xxx/apiN
on_publish http://127.0.0.1:8085/api/v1/streams http://localhost:8085/api/v1/streams;
# when client(encoder) stop publish to vhost/app/stream, call the hook,
# the request in the POST data string is a object encode by json:
# {
# "action": "on_unpublish",
# "client_id": "9308h583",
# "ip": "192.168.1.10", "vhost": "video.test.com", "app": "live",
# "stream": "livestream", "param":"?token=xxx&salt=yyy"
# }
# if valid, the hook must return HTTP code 200(Status OK) and response
# an int value specifies the error code(0 corresponding to success):
# 0
# support multiple api hooks, format:
# on_unpublish http://xxx/api0 http://xxx/api1 http://xxx/apiN
# @remark For SRS4, the HTTPS url is supported, for example:
# on_unpublish https://xxx/api0 https://xxx/api1 https://xxx/apiN
on_unpublish http://127.0.0.1:8085/api/v1/streams http://localhost:8085/api/v1/streams;
# when client start to play vhost/app/stream, call the hook,
# the request in the POST data string is a object encode by json:
# {
# "action": "on_play",
# "client_id": "9308h583",
# "ip": "192.168.1.10", "vhost": "video.test.com", "app": "live",
# "stream": "livestream", "param":"?token=xxx&salt=yyy",
# "pageUrl": "http://www.test.com/live.html"
# }
# if valid, the hook must return HTTP code 200(Status OK) and response
# an int value specifies the error code(0 corresponding to success):
# 0
# support multiple api hooks, format:
# on_play http://xxx/api0 http://xxx/api1 http://xxx/apiN
# @remark For SRS4, the HTTPS url is supported, for example:
# on_play https://xxx/api0 https://xxx/api1 https://xxx/apiN
on_play http://127.0.0.1:8085/api/v1/sessions http://localhost:8085/api/v1/sessions;
# when client stop to play vhost/app/stream, call the hook,
# the request in the POST data string is a object encode by json:
# {
# "action": "on_stop",
# "client_id": "9308h583",
# "ip": "192.168.1.10", "vhost": "video.test.com", "app": "live",
# "stream": "livestream", "param":"?token=xxx&salt=yyy"
# }
# if valid, the hook must return HTTP code 200(Status OK) and response
# an int value specifies the error code(0 corresponding to success):
# 0
# support multiple api hooks, format:
# on_stop http://xxx/api0 http://xxx/api1 http://xxx/apiN
# @remark For SRS4, the HTTPS url is supported, for example:
# on_stop https://xxx/api0 https://xxx/api1 https://xxx/apiN
on_stop http://127.0.0.1:8085/api/v1/sessions http://localhost:8085/api/v1/sessions;
# when srs reap a dvr file, call the hook,
# the request in the POST data string is a object encode by json:
# {
# "action": "on_dvr",
# "client_id": "9308h583",
# "ip": "192.168.1.10", "vhost": "video.test.com", "app": "live",
# "stream": "livestream", "param":"?token=xxx&salt=yyy",
# "cwd": "/usr/local/srs",
# "file": "./objs/nginx/html/live/livestream.1420254068776.flv"
# }
# if valid, the hook must return HTTP code 200(Status OK) and response
# an int value specifies the error code(0 corresponding to success):
# 0
on_dvr http://127.0.0.1:8085/api/v1/dvrs http://localhost:8085/api/v1/dvrs;
# when srs reap a ts file of hls, call the hook,
# the request in the POST data string is a object encode by json:
# {
# "action": "on_hls",
# "client_id": "9308h583",
# "ip": "192.168.1.10", "vhost": "video.test.com", "app": "live",
# "stream": "livestream", "param":"?token=xxx&salt=yyy",
# "duration": 9.36, // in seconds
# "cwd": "/usr/local/srs",
# "file": "./objs/nginx/html/live/livestream/2015-04-23/01/476584165.ts",
# "url": "live/livestream/2015-04-23/01/476584165.ts",
# "m3u8": "./objs/nginx/html/live/livestream/live.m3u8",
# "m3u8_url": "live/livestream/live.m3u8",
# "seq_no": 100
# }
# if valid, the hook must return HTTP code 200(Status OK) and response
# an int value specifies the error code(0 corresponding to success):
# 0
on_hls http://127.0.0.1:8085/api/v1/hls http://localhost:8085/api/v1/hls;
# when srs reap a ts file of hls, call this hook,
# used to push file to cdn network, by get the ts file from cdn network.
# so we use HTTP GET and use the variable following:
# [app], replace with the app.
# [stream], replace with the stream.
# [param], replace with the param.
# [ts_url], replace with the ts url.
# ignore any return data of server.
# @remark random select a url to report, not report all.
on_hls_notify http://127.0.0.1:8085/api/v1/hls/[app]/[stream]/[ts_url][param];
}
}
备注：可以参考conf/full.conf配置文件中的hooks.callback.vhost.com实例。
Protocol
HTTP回调的格式如下，以on_publish为例：
POST /api/v1/streams HTTP/1.1
Content-Type: application-json
Body:
{
"server_id": "vid-0xk989d",
"action": "on_publish",
"client_id": "341w361a",
"ip": "127.0.0.1",
"vhost": "__defaultVhost__",
"app": "live",
"tcUrl": "rtmp://127.0.0.1:1935/live?vhost=__defaultVhost__",
"stream": "livestream",
"param": ""
}
Note: 也可以用wireshark或tcpdump抓包验证。
Go Example
使用Go处理SRS的回调，以on_publish为例：
http.HandleFunc("/api/v1/streams", func(w http.ResponseWriter, r *http.Request) {
b, err := ioutil.ReadAll(r.Body)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
fmt.Println(string(b))
res, err := json.Marshal(struct {
Code int `json:"code"`
Message string `json:"msg"`
}{
0, "OK",
})
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
w.Write(res)
})
_ = http.ListenAndServe(":8085", nil)
Nodejs Koa Example
使用Nodejs/Koa处理SRS的回调，以on_publish为例：
const Router = require('koa-router');
const router = new Router();
router.all('/api/v1/streams', async (ctx) => {
console.log(ctx.request.body);
ctx.body = {code: 0, msg: 'OK'};
});
PHP Example
使用PHP处理SRS的回调，以on_publish为例：
$body = json_decode(file_get_contents('php://input'));
printf($body);
echo json_encode(array("code"=>0, "msg"=>"OK"));
HTTP callback events
SRS的回调事件包括：
| 事件 | 数据 | 说明 |
|---|---|---|
| on_publish | {"action": "on_publish","client_id": "9308h583","ip": "192.168.1.10", "vhost": "video.test.com", "app": "live","stream": "livestream"} | 当客户端发布流时，譬如flash/FMLE方式推流到服务器 |
| on_unpublish | {"action": "on_unpublish","client_id": "9308h583","ip": "192.168.1.10", "vhost": "video.test.com", "app": "live","stream": "livestream"} | 当客户端停止发布流时 |
| on_play | {"action": "on_play","client_id": "9308h583","ip": "192.168.1.10", "vhost": "video.test.com", "app": "live","stream": "livestream","pageUrl": "http://a.com/i.html",<br/>"param":"?k=v"} | 当客户端开始播放流时 |
| on_stop | {"action": "on_stop","client_id": "9308h583","ip": "192.168.1.10", "vhost": "video.test.com", "app": "live","stream": "livestream"} | 当客户端停止播放时 |
| on_dvr | {"action": "on_dvr","client_id": "9308h583","ip": "192.168.1.10", "vhost": "video.test.com", "app": "live","stream": "livestream","cwd": "/opt","file": "./l.xxx.flv"} | 当DVR录制关闭一个flv文件时 |
其中，
- 事件：发生该事件时，即回调指定的HTTP地址。
- HTTP地址：可以支持多个，以空格分隔，SRS会依次回调这些接口。
- 数据：SRS将数据POST到HTTP接口。
- 返回值：SRS要求HTTP服务器返回HTTP200并且response内容为整数错误码（0表示成功），其他错误码会断开客户端连接。
SRS HTTP Callback Server
SRS自带了一个默认的处理HTTP Callback的服务器，启动时需要指定端口，譬如8085端口。
启动方法：python research/api-server/server.py 8085
启动日志如下：
[winlin@dev6 srs]$ python research/api-server/server.py 8085
[2014-02-27 09:42:25][trace] api server listen at port: 8085, static_dir: /home/winlin/git/srs/trunk/research/api-server/static-dir
[2014-02-27 09:42:25][trace] start cherrypy server
[27/Feb/2014:09:42:25] ENGINE Listening for SIGHUP.
[27/Feb/2014:09:42:25] ENGINE Listening for SIGTERM.
[27/Feb/2014:09:42:25] ENGINE Listening for SIGUSR1.
[27/Feb/2014:09:42:25] ENGINE Bus STARTING
[27/Feb/2014:09:42:25] ENGINE Started monitor thread '_TimeoutMonitor'.
[27/Feb/2014:09:42:25] ENGINE Started monitor thread 'Autoreloader'.
[27/Feb/2014:09:42:25] ENGINE Serving on 0.0.0.0:8085
[27/Feb/2014:09:42:25] ENGINE Bus STARTED
Remark: For SRS4, the HTTP/HTTPS url is supported, see #1657.
HTTPS Callback
SRS4支持HTTPS回调，只需要简单的将回调地址，从http://改成https://即可，比如：
vhost your_vhost {
http_hooks {
enabled on;
on_publish https://127.0.0.1:8085/api/v1/streams;
on_unpublish https://127.0.0.1:8085/api/v1/streams;
on_play https://127.0.0.1:8085/api/v1/sessions;
on_stop https://127.0.0.1:8085/api/v1/sessions;
on_dvr https://127.0.0.1:8085/api/v1/dvrs;
on_hls https://127.0.0.1:8085/api/v1/hls;
on_hls_notify https://127.0.0.1:8085/api/v1/hls/[app]/[stream]/[ts_url][param];
}
}
Response
如果回调成功，必须响应正确的格式的数值，否则就会返回错误给客户端导致推流或播放失败。也可以参考HTTP API。格式是：
- HTTP/200, 必须返回200否则认为是错误。
- 并且，响应的内容必须是int值0，或者是JSON对象带字段code值为0。
比如：
HTTP/1.1 200 OK
Content-Length: 1
0
或者：
HTTP/1.1 200 OK
Content-Length: 11
{"code": 0}
可以查看实例回调的响应：
cd srs/trunk
python research/api-server/server.py 8085
你会明白什么是正确的响应格式。
Snapshot
HttpCallback也可以用来截图，参考snapshot
Winlin 2015.1
