nginx-upsync-module

Nginx C module, which can sync upstreams from Consul or others. It dynamically modifies backend-servers attributes (weight, max_fails,...), without need to 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 allows to expand and scale down without affecting performance.

Another module, nginx-stream-upsync-module supports NGINX stream module (TCP protocol), please be noticed.

Table of Contents

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

Status

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

Synopsis

nginx-consul:

http {
    upstream test {
        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;

        include /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;
        }

    }
}

nginx-etcd:

http {
    upstream test {
        upsync 127.0.0.1:2379/v2/keys/upstreams/test upsync_timeout=6m upsync_interval=500ms upsync_type=etcd strong_dependency=off;
        upsync_dump_path /usr/local/nginx/conf/servers/servers_test.conf;

        include /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;
        }

    }
}

upsync_lb:

http {
    upstream test {
        least_conn; //hash $uri consistent;

        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;
        upsync_lb least_conn; //hash_ketama;

        include /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;
        }

    }
}

NOTE: recommending strong_dependency is configed off and the first time included file include all the servers.

Description

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

• timely

  module send key to consul/etcd with index, consul/etcd 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/etcd 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 guarantying backend server stably provides service. And support dumping the latest config to location, so even if consul/etcd 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.
  

Directives

upsync

syntax: upsync $consul/etcd.api.com:$port/v1/kv/upstreams/$upstream_name/ [upsync_type=consul/etcd] [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/etcd interval time.

• upsync_timeout

  pulling servers from consul/etcd request timeout.

• upsync_type

  pulling servers from conf server type.

• strong_dependency

  when strong_dependency is on, nginx will pull servers from consul/etcd every time when nginx start up or reload.

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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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upsync_lb

syntax: upsync_lb $load_balance

default: round_robin/ip_hash/hash modula

context: upstream

description: mainly for least_conn and hash consistent, when using one of them, you must point out using upsync_lb.

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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;

curl http://127.0.0.1:8500/upstream_list;

show all upstreams.

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Consul_interface

Data can be taken from key/value store or service catalog. In the first case parameter upsync_type of directive must be consul. For example

        upsync 127.0.0.1:8500/v1/kv/upstreams/test upsync_timeout=6m upsync_interval=500ms upsync_type=consul strong_dependency=off;

In the second case it must be consul_services.

        upsync 127.0.0.1:8500/v1/catalog/service/test upsync_timeout=6m upsync_interval=500ms upsync_type=consul_services strong_dependency=off;

In the third case, it must be consul_health:

        upsync 127.0.0.1:8500/v1/health/service/test upsync_timeout=6m upsync_interval=500ms upsync_type=consul_health strong_dependency=off;

Services with failing health checks are marked as down with the health api.

You can add or delete backend server through consul_ui or http_interface. Below are examples for key/value store.

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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Etcd_interface

you can add or delete backend server through http_interface.

mainly like etcd, http_interface example:

• add

    curl -X PUT http://$etcd_ip:$port/v2/keys/upstreams/$upstream_name/$backend_ip:$backend_port

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

    curl -X PUT -d value="{\"weight\":1, \"max_fails\":2, \"fail_timeout\":10}" http://$etcd_ip:$port/v2/keys/$dir1/$upstream_name/$backend_ip:$backend_port

value support json format.

• delete

    curl -X DELETE http://$etcd_ip:$port/v2/keys/upstreams/$upstream_name/$backend_ip:$backend_port

• adjust-weight

    curl -X PUT -d "{\"weight\":2, \"max_fails\":2, \"fail_timeout\":10}" http://$etcd_ip:$port/v2/keys/$dir1/$upstream_name/$backend_ip:$backend_port

• mark server-down

    curl -X PUT -d value="{\"weight\":2, \"max_fails\":2, \"fail_timeout\":10, \"down\":1}" http://$etcd_ip:$port/v2/keys/$dir1/$upstream_name/$backend_ip:$backend_port

• check

    curl http://$etcd_ip:$port/v2/keys/upstreams/$upstream_name

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Check_module

check module support.

check-conf:

http {
    upstream test {
        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;

        check interval=1000 rise=2 fall=2 timeout=3000 type=http default_down=false;
        check_http_send "HEAD / HTTP/1.0\r\n\r\n";
        check_http_expect_alive http_2xx http_3xx;

    }

    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;
        }

        location = /upstream_status {
            check_status;
            access_log off;
        }

    }
}

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TODO

• support zookeeper and so on

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Compatibility

Master branch is compatible with nginx-1.9.8+.

The branch of nginx-upsync-1.8.x is compatible with Nginx-1.8.x and with tengine-2.2.0.

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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

patch -p1 < /path/to/nginx-upstream-check-module/check_1.7.5+.patch
./configure --add-module=/path/to/nginx-upstream-check-module --add-module=/path/to/nginx-upsync-module
make
make install

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Code style

Code style is mainly based on style

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Author

Xiaokai Wang (王晓开) xiaokai.wang@live.com, 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 xiaokai.wang@live.com/xiaokai.wang@live.com

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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