Day 50 - which version, which modules ? Or ngx-build.

Today, I figured I would give a guy on the mailing list a hand. Poor guy asked the question a couple of times and got no answer. Of course, I don't know the answer but I figured I could learn a few things trying to help. So, I started creating a support directory in my nginx directory and another sub-directory for his case (map-proxy). Yes, that's the way I am: I like it when my room is in order. Now, I figured I would use Test::Nginx to setup something quickly. So, I started wondering: which version of nginx (I have at least three in my nginx directory)? Which modules? I need to completely set an environment for it. But I'm not going to download the full source just for that... Not having an easy way to setup a test environment for a specific nginx configuration has been a rock in my shoe (or something else somewhere else) for quite some time now and I decided to fix it, at last...

This looks again like I'm going to get side-tracked and get something else done than what was originally planned. And I'll drag you along... ;) That's what adventure trips are for, aren't they?

So, I'm sick of having to figure out what is the right version of nginx for the task at hand and where I put this in my directories. That's where my dream started: a perfect world where I could order a nginx 0.8.54 with just the echo module. Or even better, the module I'm working on.

Here is the usage I would like to have:

Usage: ngx-build [main-source] [module-source]
  main-source      Can be a VERSION or a DIRECTORY.
                   Look for main nginx source in DIRECTORY.
                   Look for main nginx source in a directory
                   named nginx-VERSION in $HOME, $HOME/nginx
                   and $NGX_ROOT (if set).
  module-source    DIRECTORY or PATTERN. Use DIRECTORY to indicate
                   a module directory (has a config file). Append
                   * before and after PATTERN and look 
                   for module directories in $HOME,
                   $HOME/nginx and $NGX_ROOT (if set) that match
                   the resulting pattern.

Example: ngx-build 0.8.54 echo

Invoking this should configure with the appropriate options, make the executable and last but not least copy it in the current folder.

That gave me something like this ngx-build script (feel free to use/patch/do whatever you like):

#!/bin/sh
launch_path=`pwd`
function test_ngx_path() {
  if test -z "$my_ngx_path" -a -d "$1" -a -f "$1/src/core/nginx.c"; then
    my_ngx_path="$1";
  fi;
}

test_ngx_path "$1";
if test "$NGX_ROOT"; then
  test_ngx_path "$NGX_ROOT/nginx-$1";
fi
test_ngx_path "$HOME/nginx-$1";
test_ngx_path "$HOME/nginx/nginx-$1";

function test_module_path() {
  if test -z "$my_module_arg" -a -f "$1/config"; then
    my_module_arg="--add-module=$1";
  fi;
}

test_module_path "$2";
if test "$NGX_ROOT"; then
  test_module_path "$NGX_ROOT"/*"$2"*;
fi
test_module_path "$HOME"/nginx/*"$2"*;

cd "$my_ngx_path"
if test -z "$my_module_arg"; then
  ./configure --with-debug
else
  ./configure "$my_module_arg" --with-debug
fi

make -C $my_ngx_path
cp $my_ngx_path/objs/nginx $launch_path

Besides the usual problems you get when trying to write shell scripts (how many escapes, what is the right syntax for testing something, etc.), there is one particular thing you should know about the configure script of nginx: it MUST be run in the folder where it is. Yes, most people follow the usual mantra: "configure && make && make install" or another slightly different version. But sometimes you would like to do it differently. Well, you are more likely to run into problems on less-travelled roads. Or do you? At least with software, this is the way (also known as: if it's not tested, it's not going to work).

And I have at least two uses for this script:

% ngx-build 0.8.54 echo
% ngx-build 0.9.5 `pwd`

Would be better if the second invocation could use . for the current directory but that does not seem to work out of the box and I don't care to spend the extra time on it for now. If anybody does or want to add some extra feature, just let me know.

Oh, in the meantime someone else answered the question. Next time, may be I won't be side-tracked...