NAME

Test::Nginx - Testing modules for Nginx C module development

DESCRIPTION

This distribution provides two testing modules for Nginx C module

development

• Test::Nginx::LWP
• Test::Nginx::Socket

All of them are based on Test::Base.

Usually, Test::Nginx::Socket is preferred because it works on a much lower level and not that fault tolerant like Test::Nginx::LWP.

Also, a lot of connection hang issues (like wrong "r->main->count" value in nginx 0.8.x) can only be captured by Test::Nginx::Socket because Perl's LWP::UserAgent client will close the connection itself which will conceal such issues from the testers.

Test::Nginx automatically starts an nginx instance (from the "PATH" env) rooted at t/servroot/ and the default config template makes this nginx instance listen on the port 1984 by default. One can specify a different port number by setting his port number to the "TEST_NGINX_PORT" environment, as in

export TEST_NGINX_PORT=1989

etcproxy integration
The default settings in etcproxy
(https://github.com/chaoslawful/etcproxy) makes this small TCP proxy split the TCP packets into bytes and introduce 1 ms latency among them.

There's usually various TCP chains that we can put etcproxy into, for example

Test::Nginx <=> nginx

$ ./etcproxy 1234 1984

Here we tell etcproxy to listen on port 1234 and to delegate all the TCP traffic to the port 1984, the default port that Test::Nginx makes nginx listen to.

And then we tell Test::Nginx to test against the port 1234, where etcproxy listens on, rather than the port 1984 that nginx directly listens on:

$ TEST_NGINX_CLIENT_PORT=1234 prove -r t/

Then the TCP chain now looks like this:

Test::Nginx <=> etcproxy (1234) <=> nginx (1984)

So etcproxy can effectively emulate extreme network conditions and exercise "unusual" code paths in your nginx server by your tests.

In practice, tons of weird bugs can be captured by this setting. Even ourselves didn't expect that this simple approach is so effective.

nginx <=> memcached
We first start the memcached server daemon on port 11211:

memcached -p 11211 -vv

and then we another etcproxy instance to listen on port 11984 like this

$ ./etcproxy 11984 11211

Then we tell our t/foo.t test script to connect to 11984 rather than

11211

# foo.t use Test::Nginx::Socket; repeat_each(1); plan tests => 2 * repeat_each() * blocks(); $ENV{TEST_NGINX_MEMCACHED_PORT} ||= 11211; # make this env take a default value run_tests();

__DATA__

=== TEST 1: sanity --- config location /foo {

set $memc_cmd set; set $memc_key foo; set $memc_value bar; memc_pass 127.0.0.1:$TEST_NGINX_MEMCACHED_PORT; } --- request

GET /foo --- response_body_like: STORED

The Test::Nginx library will automatically expand the special macro $TEST_NGINX_MEMCACHED_PORT to the environment with the same name. You can define your own $TEST_NGINX_BLAH_BLAH_PORT macros as long as its prefix is "TEST_NGINX_" and all in upper case letters.

And now we can run your test script against the etcproxy port 11984:

TEST_NGINX_MEMCACHED_PORT=11984 prove t/foo.t

Then the TCP chains look like this:

Test::Nginx <=> nginx (1984) <=> etcproxy (11984) <=> memcached (11211)

If "TEST_NGINX_MEMCACHED_PORT" is not set, then it will take the default value 11211, which is what we want when there's no etcproxy configured:

Test::Nginx <=> nginx (1984) <=> memcached (11211)

This approach also works for proxied mysql and postgres traffic. Please see the live test suite of ngx_drizzle and ngx_postgres for more details.

Usually we set both "TEST_NGINX_CLIENT_PORT" and "TEST_NGINX_MEMCACHED_PORT" (and etc) at the same time, effectively yielding the following chain:

Test::Nginx <=> etcproxy (1234) <=> nginx (1984) <=> etcproxy (11984) <=> memcached (11211)

as long as you run two separate etcproxy instances in two separate terminals.

It's easy to verify if the traffic actually goes through your etcproxy server. Just check if the terminal running etcproxy emits outputs. By default, etcproxy always dump out the incoming and outgoing data to stdout/stderr.

valgrind integration
Test::Nginx has integrated support for valgrind (<http://valgrind.org>) even though by default it does not bother running it with the tests because valgrind will significantly slow down the test sutie.

First ensure that your valgrind executable visible in your PATH env. And then run your test suite with the "TEST_NGINX_USE_VALGRIND" env set to

true

TEST_NGINX_USE_VALGRIND=1 prove -r t

If you see false alarms, you do have a chance to skip them by defining a ./valgrind.suppress file at the root of your module source tree, as in

<https://github.com/chaoslawful/drizzle-nginx-module/blob/master/valgrin d.suppress>

This is the suppression file for ngx_drizzle. Test::Nginx will automatically use it to start nginx with valgrind memcheck if this file does exist at the expected location.

If you do see a lot of "Connection refused" errors while running the tests this way, then you probably have a slow machine (or a very busy one) that the default waiting time is not sufficient for valgrind to start. You can define the sleep time to a larger value by setting the "TEST_NGINX_SLEEP" env:

TEST_NGINX_SLEEP=1 prove -r t

The time unit used here is "second". The default sleep setting just fits my ThinkPad ("Core2Duo T9600").

Applying the no-pool patch to your nginx core is recommended while running nginx with valgrind:

<https://github.com/shrimp/no-pool-nginx>

The nginx memory pool can prevent valgrind from spotting lots of invalid memory reads/writes as well as certain double-free errors. We did find a lot more memory issues in many of our modules when we first introduced the no-pool patch in practice ;)

There's also more advanced features in Test::Nginx that have never documented. I'd like to write more about them in the near future ;)

Nginx C modules that use Test::Nginx to drive their test suites

ngx_echo

<http://github.com/agentzh/echo-nginx-module>

ngx_headers_more

<http://github.com/agentzh/headers-more-nginx-module>

ngx_chunkin

<http://wiki.nginx.org/NginxHttpChunkinModule>

ngx_memc

<http://wiki.nginx.org/NginxHttpMemcModule>

ngx_drizzle

<http://github.com/chaoslawful/drizzle-nginx-module>

ngx_rds_json

<http://github.com/agentzh/rds-json-nginx-module>

ngx_xss

<http://github.com/agentzh/xss-nginx-module>

ngx_srcache

<http://github.com/agentzh/srcache-nginx-module>

ngx_lua

<http://github.com/chaoslawful/lua-nginx-module>

ngx_set_misc

<http://github.com/agentzh/set-misc-nginx-module>

ngx_array_var

<http://github.com/agentzh/array-var-nginx-module>

ngx_form_input

<http://github.com/calio/form-input-nginx-module>

ngx_iconv

<http://github.com/calio/iconv-nginx-module>

ngx_set_cconv

<http://github.com/liseen/set-cconv-nginx-module>

ngx_postgres

<http://github.com/FRiCKLE/ngx_postgres>

ngx_coolkit

<http://github.com/FRiCKLE/ngx_coolkit>

SOURCE REPOSITORY

This module has a Git repository on Github, which has access for all.

http://github.com/agentzh/test-nginx

If you want a commit bit, feel free to drop me a line.

AUTHORS

agentzh (章亦æ^~¥) "<agentzh@gmail.com>"

Antoine BONAVITA "<antoine.bonavita@gmail.com>"

COPYRIGHT & LICENSE

Copyright (c) 2009-2011, Taobao Inc., Alibaba Group (<http://www.taobao.com>).

Copyright (c) 2009-2011, agentzh "<agentzh@gmail.com>".

Copyright (c) 2011, Antoine Bonavita "<antoine.bonavita@gmail.com>".

This module is licensed under the terms of the BSD license.

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.
• Neither the name of the Taobao Inc. nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

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.

SEE ALSO

Test::Nginx::LWP, Test::Nginx::Socket, Test::Base.

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