Summary: last month I set up Hudson as our continuous integration server. And I constantly show Hudson’s front page on a laptop in a visible location, which increased interest and usage a lot!
Somewhere in February, after working here for a month, I set up a buildbot. I’m all in favour of some practical project automation. Having some machine automatically testing your code every time you make a change is one of the essentials. It also forces you to make your builds repeatable without any manual steps (so: buildout!), which is a good thing, too.
Problem: it did test everything pretty fine, but almost nobody looked at it.
I saw Hudson a couple of times already in some blog posts, but last May’s djangocon.eu in Berlin made sure I wanted to replace buildbot with Hudson, see for instance Eric Holscher’s talk.
There are a couple of how-to-integrate-hudson-with-django-or-python tutorials on-line, just google for them. I’ll just make some quick comments here:
There’s not only python in there! A colleague added R projects in there.
You’ll need to get your tests to spit out xml output. We now run our tests
with the “nose” test runner by using django-nose. Next to the setup.py I
added a setup.cfg with the following content, this tells nose to spit
out xml:
[nosetests]
with-xunit=1
Cobertura plug-in: code coverage measurement. This also needs xml output.
With coverage.py, you just need to call coverage xml.
“Violations” plug-in: switch on ‘pylint’ checking for your code. I don’t
actually use pylint: I run pep8 and pyflakes
over the code. You do need to redirect both tools’ output to a text file and
fix the output up a bit to match what the plug-in expects. Effectively:
every line that contains [E is an error, [W is a warning. I copied
someone’s perl command-line for this. Pep8 is warning level, pyflakes is
error level:
pep8 dir_with_python | perl -ple 's/: [WE](\\d+)/: [W$1]/' > pep8.txt
pyflakes dir_with_python | perl -ple 's/:\\ /: [E] /' >> pep8.txt
I included the rhino command line version of jslint. An error here means the script returns with a non-zero exit code, which means a test failure for Hudson.
All the above items are run in two or three script steps in Hudson. In the end I grouped everything together a bit in python scripts, btw.
Hurray for Hudson!
My name is Reinout van Rees and I work a lot with Python (programming language) and Django (website framework). I live in The Netherlands and I'm happily married to Annie van Rees-Kooiman.
Most of my website content is in my weblog. You can keep up to date by subscribing to the automatic feeds (for instance with Google reader):
Social effects¶
In August I installed Hudson and everyone started loving it. What did I do?
I installed Hudson on our buildbot machine and configured a couple of projects. And switched off the buildbot and redirected all URLs to Hudson.
I showed it to a couple of colleagues.
I asked for an old laptop and got it placed in a visible location in our development room with a full screen Hudson front page.
What was the effect?
Highly visible. So for a few days, everyone who got into the room wanted to know what it was. Instant invitation for a demo! Most people now know that our software is automatically tested and that it catches errors from time to time.
Nice visualization and nice graphs for code coverage, code neatness and overall health. Nice visualization really means you want to look at it.
Highly visible if something goes wrong. You really really want to fix your broken test. As soon as something is red (especially when demoing Hudson to a visitor) they want to know who the culprit is :-)
I’ve got pep8/pyflakes reports in there, too. So you see which code is neat. So you finally get a bonus for paying attention to your pep8 coding style. The effect? Many packages suddenly got miraculously neater.
As you see the code coverage in a graph over time, the amount of tests also miraculously increased.
More trust in the software. I noticed it myself when adding automatic jslint javascript checking: important, as just a single missed semicolon can throw off internet explorer in our javascript-heavy web apps. And even one missing semicolon is a flogging offense in our Hudson setup: a Red Dot… So having jslint running all the time made me feel much safer.
The boss also looked at it and suggested a different picture than the boring green ball. So the “successful build” icon is now his photograph with a green halo glow :-) Talk about management buy-in…
Visibility? Just when I was about to make a photograph, our sysadmin shut down the machine. “What?” “Oh, I’m just attaching a bigger monitor”. Hurray! I had not even requested that and suddenly we have a nicer bigger more visible monitor.