NAME

Test::Nginx - Data-driven test scaffold for Nginx C module and OpenResty Lua library development

DESCRIPTION

This distribution provides two testing modules for Nginx C module development:

Test::Nginx::Socket (This is recommended.)
Test::Nginx::LWP (This is obsolete.)

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
  --- error_code: 201

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 suite.

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/valgrind.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_rds_csv: http://github.com/agentzh/rds-csv-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
Naxsi: http://code.google.com/p/naxsi/

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.

DEBIAN PACKAGES

António P. P. Almeida is maintaining a Debian package for this module in his Debian repository: http://debian.perusio.net

Community

English Mailing List

The openresty-en mailing list is for English speakers: https://groups.google.com/group/openresty-en

Chinese Mailing List

The openresty mailing list is for Chinese speakers: https://groups.google.com/group/openresty

AUTHORS

Yichun Zhang (agentzh) <agentzh@gmail.com>

Antoine BONAVITA <antoine.bonavita@gmail.com>

COPYRIGHT & LICENSE

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 authors 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.

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