ngx_http_dyups_module

Description

This module can be used to update your upstream-list without reloadding Nginx.

TODO:

It can not work with common `nginx_upstream_check_module`.

Compilation

The module is not compiled into Tengine by default. It can be enabled with '--with-http_dyups_module'
configuration parameter, and enabled lua support with '--with-http_dyups_lua_api'.
But it can not be compiled as a '.so'.

Example

file: conf/nginx.conf

daemon off;
error_log logs/error.log debug;
events {
}
http {
dyups_upstream_conf conf/upstream.conf;
include conf/upstream.conf;
server {
listen 8080;
location / {
proxy_pass http://$host;
}
}
server {
listen 8088;
location / {
echo 8088;
}
}
server {
listen 8089;
location / {
echo 8089;
}
}
server {
listen 8081;
location / {
dyups_interface;
}
}
}

file: conf/upstream.conf

upstream host1 {
server 127.0.0.1:8088;
}
upstream host2 {
server 127.0.0.1:8089;
}

Directives

Syntax: _dyupsinterface
Default: none
Context: loc

This directive set the interface location where you can add or delete the upstream list. See the section of Interface for detail.


Syntax: _dyups_read_msgtimeout time
Default: 1s
Context: main

This directive set the interval of workers readding the commands from share memory.


Syntax: _dyups_shm_zonesize size
Default: 2M
Context: main

This directive set the size of share memory which used to store the commands.


Syntax: _dyups_upstreamconf path
Default: none
Context: main

This directive set the path of file which you dumped all of upstreams' configs, it will be loaded in init process after process respwan to restore upstreams.


Syntax: _dyupstrylock on | off
Default: off
Context: main

You will get a better prefomance but it maybe not stable, and you will get a '409' when the update request conflicts with others.

restful interface

  • /detail get all upstreams and their servers
  • /list get the list of upstreams
  • /upstream/name find the upstream by it's name

  • /upstream/name update one upstream

  • body commands;
  • body server ip:port;

  • /upstream/name delete one upstream

Call the interface, when you get the return code is HTTP_INTERNAL_SERVER_ERROR 500, you need to reload nginx to make the Nginx work at a good state.

If you got HTTP_CONFLICT 409, you need resend the same commands again latter.

The /list and /detail interface will return HTTP_NO_CONTENT 204 when there is no upstream.

Other code means you should modify your commands and call the interface again.

ATTENEION: You also need a third-party to generate the new config and dump it to Nginx'conf directory.

» curl -H "host: dyhost" 127.0.0.1:8080
<html>
<head><title>502 Bad Gateway</title></head>
<body bgcolor="white">
<center><div class="dh">502 Bad Gateway</div></center>
* * *
<center>nginx/1.3.13</center>
</body>
</html>
» curl -d "server 127.0.0.1:8089;server 127.0.0.1:8088;" 127.0.0.1:8081/upstream/dyhost
success
» curl -H "host: dyhost" 127.0.0.1:8080
8089
» curl -H "host: dyhost" 127.0.0.1:8080
8088
» curl 127.0.0.1:8081/detail
host1
server 127.0.0.1:8088
host2
server 127.0.0.1:8089
dyhost
server 127.0.0.1:8089
server 127.0.0.1:8088
» curl -i -X DELETE 127.0.0.1:8081/upstream/dyhost
success
» curl 127.0.0.1:8081/detail
host1
server 127.0.0.1:8088
host2
server 127.0.0.1:8089

API

extern ngx_flag_t ngx_http_dyups_api_enable;
ngx_int_t ngx_dyups_update_upstream(ngx_str_t *name, ngx_buf_t *buf,
ngx_str_t *rv);
ngx_int_t ngx_dyups_delete_upstream(ngx_str_t *name, ngx_str_t *rv);

NOTICE:
you should add the directive dyups_interface into your config file to active this feature

content_by_lua '
local dyups = require "ngx.dyups"
local status, rv = dyups.update("test", [[server 127.0.0.1:8088;]]);
ngx.print(status, rv)
if status ~= 200 then
ngx.print(status, rv)
return
end
ngx.print("update success")
status, rv = dyups.delete("test")
if status ~= 200 then
ngx.print(status, rv)
return
end
ngx.print("delete success")
';