Nginx and Mercurial setup

Some weeks ago I switched to Nginx and quit Apache and was quite happy with it. I was so happy that completely forgot about my Mercurial repositories hosted on same server. This happen when I was in hurry and needed to push and pull some changes,  damn.

At first I quickly restored Apache, did all needed changes and switched back to Nginx. For sure, I did not like this way and explored how I can connect Mercurial directly to Nginx. I was quite surprised how easy it is and how flexible.

Continue reading...

Mercurial via Apache setup

I had Mercurial setup through Apache in a very standard way.

/var/hg - Holding all my repositaries

/var/hg/hgweb.config

[collections]
repos/ = repos/

/var/hg/hgwebdir.cgi - For Apache CGI support

/var/hg/hguser - for user passwords in htpasswd format

Apache configuration was the following

ScriptAliasMatch ^/hg(.*) /var/hg/hgwebdir.cgi$1
<Directory /var/hg>
  Options ExecCGI FollowSymLinks
  AllowOverride None
</Directory>

<Location /hg>
   AuthType Basic
   AuthName "Mercurial repositories"
   AuthUserFile /var/hg/hgusers
   Require valid-user
</Location>

Switch to Nginx was really painless.

Nginx and Mercurial setup

Prepare Mercurial

First step I switched to FastCGI instead of CGI. To do this I copied file hgwebdir.fcgi to my repo root /var/hg and made it executable

copy /usr/share/doc/mercurial-common/examples/hgwebdir.fcgi /var/hg
chmod +x /var/hg/hgwebdir.fcgi

Or grab the file here

wget http://selenic.com/repo/hg/raw-file/tip/contrib/hgwebdir.fcgi

Next step is to install something that can spawn FastCGI processes, sine Nginx can not do this by itself.  This is easy with spawn-cgi

#apt-get install spawn-fcgi

I configured it via local unix socket instead of TCP port, it seems to me this way it is more secure. Run it like this:

#spawn-fcgi -u www-data -g www-data -s /tmp/mercurial.sock -d /var/hg/ -- /var/hg/hgwebdir.fcgi

At first start I've run into the problem

spawn-fcgi: child exited with: 1

After running with "-n" switch to see debug output, I  realised that I was missing one python module needed for a setup.

Traceback (most recent call last):
 File "/var/hg/hgwebdir.fcgi", line 25, in
 from flup.server.fcgi import WSGIServer
 File "/usr/lib/pymodules/python2.6/mercurial/demandimport.py", line 106, in _demandimport
 mod = _origimport(name, globals, locals)
 ImportError: No module named flup.server.fcgi

To fix this I installed missing python packages and issue was fixed.

#apt-get install python-flup

Configure Nginx

Edit file /etc/nginx/sites-available/mercurial.conf and add the following server definition:

server {
   listen 80;
   server_name YOUR_MERCURIAL_DOMAIN;

   location / {
     auth_basic "Secure Login";
     auth_basic_user_file /var/hg/hgusers;
     include fastcgi_params;
     fastcgi_param PATH_INFO $uri;
     fastcgi_param REMOTE_USER $remote_user;
     fastcgi_intercept_errors on;
     fastcgi_pass unix:/tmp/mercurial.sock;
  } 
}

The above settings will setup a new virtual host, where all traffic is redirected to the Mercurial FastCGI wrapper. It is important that you forward the PATH_INFO and REMOTE_USER variables. Mercurial will not work correctly without these.

Be sure that file /var/hg/hgusers contains all your Mercurial users with passwords, it can be created using htpasswd tool shipped with Apache.

Restart Nginx and try to to push pull.

Misc

One thing that changed was repositary path. Before it has /hg/ in path line

http://a32.me/hg/project1

Now it become a full virtual host and changed to:

http://hg.a32.me/project1

I have to reconfigure all my projects, but it is not a pain like it was with CVS.

Next thing I though about, I can move repositories under its own uid:gid and not run it under www-data, this can improve security.

Do not forget to include running spawn-fcgi into /etc/rc.local for automatically start on system boot.

Links

My story is based on these links.

• http://www.opennet.ru/base/dev/mercurial_http.txt.html
• http://geeksharp.com/2010/01/20/mercurial-web-with-fastcgi-nginx/
• http://fosswire.com/post/2009/08/hosting-mercurial-repositories-with-nginx/
• http://www.softwareprojects.com/resources/programming/t-how-to-serve-mercurial-hg-repository-over-nginx-1856.html
• http://www.dikant.de/2009/07/29/running-mercurial-with-fastcgi-in-nginx/

My short bio