Mercurial build on push - mercurial

Question

I'd like for a build to be done (on the server) each time a push is made to our central Mercurial repository.
Builds are usually kicked off on our build server by running a Visual Build file either manually or via a scheduled task.
What are the ways of achieving this?
Simple, low impact solutions are preferred.

Answer 1

As Pablo suggested, you can do this with a hook, but you'll need an incoming hook on the server side. This hook runs "after a changeset has been pulled, pushed, or unbundled into the local repository" (hgrc manpage).
Edit the .hg/hgrc file of the repository located on the server and define your build hook as follows:
[hooks]
incoming = /path/to/executable-build-script
Of course, the build script called here just needs to be a trigger for whatever build process you actually use.
Note that an incoming hook runs for every single changeset in a push. If you don't want this, use a changegroup hook -- it runs only once for each push, no matter how many changesets it carries.

Answer 2

Another way, in addition to the hooks that Pablo mentions, is to set up a continuous integration server, like TeamCity. Then you could ask TeamCity to monitor your repository, pull new changesets and start the visual build script for you.

Answer 3

Disclaimer
These findings are for tortoisehg client and mercurial server behind apache on win32.
Try #1
The naive solution would be to make your push kick off the build.
In .hg\hgrc
[hooks]
incoming=.hg\build.py
In build.py
os.system('\Progra~2\Micros~2.0\Common7\IDE\devenv /build release project.sln > logfile')
Problem
What you'll find is that, after a push, the tortoise hg client won't return until your os.system call returns. This may or not be acceptable. In my shop a build took about 20 minutes, and my boss deemed that unacceptable.
Try #2
My solution was for the hook to return immediately after creating a REQUESTBUILD file to the root directory.
In .hg\hgrc
[hooks]
incoming = .hg\write_buildrequest_file.bat
In .hg\write_buildrequest_file.bat
echo REQUESTBUILD > \REQUESTBUILD
Meanwhile, I had a python script running in an infinite loop, checking for the presence of REQUESTBUILD.
In .hg\monitor_buildrequest_file.py
import popen2, time, os
import subprocess
while True:
if os.path.exists("\REQUESTBUILD"):
os.system("del \REQUESTBUILD")
os.chdir("/yourrepo/.hg")
retcode = subprocess.call("\python27\python.exe build.py")
else:
time.sleep(10)
build.py would generate an HTML file of results, which the submitter would have to pull via their web browser.
There are other issues (pushes while a build is commencing, saving historical results, building out of the working directory vs copying elsewhere) but this is the general idea.

Answer 4

You need to handle repository events with hooks.
So, after commit event you need to run a script that will perform your build accordingly.