Name

nginx-upsync-module - Nginx C module, sync upstreams from consul or others, dynamiclly modify backend-servers attribute(weight, max_fails,...), needn't reload nginx.

It may not always be convenient to modify configuration files and restart NGINX. For example, if you are experiencing large amounts of traffic and high load, restarting NGINX and reloading the configuration at that point further increases load on the system and can temporarily degrade performance.

The module can be more smoothly expansion and constriction, and will not influence the performance.

Table of Contents

• Name
• Status
• Synopsis
• Description
• Directives
  • upsync
    • upsync_interval
    • upsync_timeout
    • upsync_type
    • strong_dependency
  • upsync_dump_path
  • upstream_show
• Consul_interface
• TODO
• Compatibility
• Installation
• Author
• Copyright and License
• See Also
• Source Dependency

Status

This module is still under active development and is considered production ready.

Synopsis

http {
    upstream test {
        # fake server otherwise ngx_http_upstream will report error when startup
        server 127.0.0.1:11111;

        # all backend server will pull from consul when startup and will delete fake server
        upsync 127.0.0.1:8500/v1/kv/upstreams/test upsync_timeout=6m upsync_interval=500ms upsync_type=consul strong_dependency=off;
        upsync_dump_path /usr/local/nginx/conf/servers/servers_test.conf;
    }

    upstream bar {
        server 127.0.0.1:8090 weight=1, fail_timeout=10, max_fails=3;
    }

    server {
        listen 8080;

        location = /proxy_test {
            proxy_pass http://test;
        }

        location = /bar {
            proxy_pass http://bar;
        }

        location = /upstream_show {
            upstream_show;
        }

    }
}

Description

This module provides a method to discover backend servers. Supporting dynamicly adding or deleting backend server through consul and dynamicly adjusting backend servers weight, module will timely pull new backend server list from consul to upsync nginx ip router. Nginx needn't reload. Having some advantages than others:

• timely

  module send key to consul with index, consul will compare it with its index, if index doesn't change connection will hang five minutes, in the period any operation to the key-value, will feed back rightaway.
  

• performance

  Pulling from consul equal a request to nginx, updating ip router nginx needn't reload, so affecting nginx performance is little.
  

• stability

  Even if one pulling failed, it will pull next upsync_interval, so guaranteing backend server stably provides service. And support dumping the latest config to location, so even if consul hung up, and nginx can be reload anytime. 
  

• health_check

  nginx-upsync-module support adding or deleting servers health check, needing nginx_upstream_check_module. Recommending nginx-upsync-module + nginx_upstream_check_module.
  

Diretives

upsync

syntax: upsync $consul.api.com:$port/v1/kv/upstreams/$upstream_name [upsync_type=consul] [upsync_interval=second/minutes] [upsync_timeout=second/minutes] [strong_dependency=off/on]

default: none, if parameters omitted, default parameters are upsync_interval=5s upsync_timeout=6m strong_dependency=off

context: upstream

description: Pull upstream servers from consul/etcd... .

The parameters' meanings are:

• upsync_interval

  pulling servers from consul interval time.

• upsync_timeout

  pulling servers from consul request timeout.

• upsync_type

  pulling servers from conf server type.

• strong_dependency

  when nginx start up if depending on consul, and consul is not working, nginx will boot failed, otherwise booting normally.

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upsync_dump_path

syntax: upsync_dump_path $path

default: /tmp/servers_$host.conf

context: upstream

description: dump the upstream backends to the $path.

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upstream_show

syntax: upstream_show

default: none

context: upstream

description: Show specific upstream all backend servers.

     location /upstream_list {
         upstream_show;
     }

curl http://127.0.0.1:8500/upstream_list?test;

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Consul_interface

you can add or delete backend server through consul_ui or http_interface.

http_interface example:

• add

    curl -X PUT http://$consul_ip:$port/v1/kv/upstreams/$upstream_name/$backend_ip:$backend_port

default: weight=1 max_fails=2 fail_timeout=10 down=0 backup=0;

    curl -X PUT -d "{\"weight\":1, \"max_fails\":2, \"fail_timeout\":10}" http://$consul_ip:$port/v1/kv/$dir1/$upstream_name/$backend_ip:$backend_port
or
    curl -X PUT -d '{"weight":1, "max_fails":2, "fail_timeout":10}' http://$consul_ip:$port/v1/kv/$dir1/$upstream_name/$backend_ip:$backend_port

value support json format.

• delete

    curl -X DELETE http://$consul_ip:$port/v1/kv/upstreams/$upstream_name/$backend_ip:$backend_port

• adjust-weight

    curl -X PUT -d "{\"weight\":2, \"max_fails\":2, \"fail_timeout\":10}" http://$consul_ip:$port/v1/kv/$dir1/$upstream_name/$backend_ip:$backend_port
or
    curl -X PUT -d '{"weight":2, "max_fails":2, "fail_timeout":10}' http://$consul_ip:$port/v1/kv/$dir1/$upstream_name/$backend_ip:$backend_port

• mark server-down

    curl -X PUT -d "{\"weight\":2, \"max_fails\":2, \"fail_timeout\":10, \"down\":1}" http://$consul_ip:$port/v1/kv/$dir1/$upstream_name/$backend_ip:$backend_port
or
    curl -X PUT -d '{"weight":2, "max_fails":2, "fail_timeout":10, "down":1}' http://$consul_ip:$port/v1/kv/$dir1/$upstream_name/$backend_ip:$backend_port

• check

    curl http://$consul_ip:$port/v1/kv/upstreams/$upstream_name?recurse

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TODO

• support etcd, zookeeper and so on

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Compatibility

The module was developed base on nginx1.8.0.

Compatible with Nginx-1.8.x.

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Installation

This module can be used independently, can be downloadGithub.

Grab the nginx source code from nginx.org, for example, the version 1.8.0 (see nginx compatibility), and then build the source with this module:

wget 'http://nginx.org/download/nginx-1.8.0.tar.gz'
tar -xzvf nginx-1.8.0.tar.gz
cd nginx-1.8.0/

./configure --add-module=/path/to/nginx-upsync-module
make
make install

if you support nginx-upstream-check-module

./configure --add-module=/path/to/nginx-upstream-check-module --add-module=/path/to/nginx-upsync-module
make
make install

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Author

Xiaokai Wang (王晓开) [email protected], Weibo Inc.

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Copyright and License

This README template copy from agentzh.

This module is licensed under the BSD license.

Copyright (C) 2014 by Xiaokai Wang [email protected]/[email protected]

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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see also

• the nginx_upstream_check_module: https://github.com/alibaba/tengine/blob/master/src/http/ngx_http_upstream_check_module.c
• the nginx_upstream_check_module patch: https://github.com/yaoweibin/nginx_upstream_check_module
• or based on https://github.com/xiaokai-wang/nginx_upstream_check_module

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source dependency

• Cjson: https://github.com/kbranigan/cJSON
• http-parser: https://github.com/nodejs/http-parser

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