Using Docker as a Python Development Environment

http://continuousdelivery.uglyduckling.nl/uncategorized/using-docker-as-a-python-development-environment/

by amouat • 12 years ago

61 29 12 years ago

continuousdelivery.uglyduckling.nl

netcraft• 12 years ago

I'm confused how they created the docker image with python, postgresql and apache in the first place? Is it the FROM python_webapp that defines that? python_webapp being the name of a docker image already defined? How hard is it to set up the docker image initially?

Edit: NVM, it is documented here (I missed it the first read through) http://continuousdelivery.uglyduckling.nl/continuous-deliver...

mbreese2• 12 years ago

I'm more curious as to how to get a lightweight Docker container running Python. The one they use pulls in an Ubuntu Quantal image, which isn't something that I'd normally use (I'm more in the RHEL/CentOS camp).

So, how would one go about building something like this that isn't tied to a container that pulls in a whole OS? Or is that just not the way these things work? Or am I just too used to virtualenv?

chanux2• 12 years ago

You can use CentOS if you prefer that. Also the OS is pulled just once.

monatron• 12 years ago

to be honest i still usually implement virtualenv when constructing a container.

This way I'm sure that I'm not interfering with the os-level python dependencies, and any activation of the environment is handled by a "python-webapp" baseimage that I use for all of my projects.

dschiptsov2• 12 years ago

Why, why should I do this?) What's wrong with python3 and Postgresql which are packaged in last Ubuntu?

How about the principle of not adding unnecessary entities/complications?

klibertp4• 12 years ago

It's probably not needed when working on a single project - although even then Docker has some advantages, like being able to have another distro in the image than you have natively - but it makes your life infinitely simpler when you need to work with two or more projects with differing dependencies.

lvh• 12 years ago

That seems orthogonal to using virtual environments or not. Are you talking about putting them on your dev machine? In that case: reproducible development environments.

dschiptsov2• 12 years ago

"reproducible development environments" - what does this mean?)

quasarj• 12 years ago

I'm not sure about this guy's list of issues with virtualenv.

Point 1 (he forgets to activate it) is not an issue at all. You could forget to "activate" your docker too.

Point 3 (he doesn't want to run it in production) but running docker in production is okay?

That said, he made a good point about non-python dependencies.

amouat• 12 years ago

Regarding point 1, the way in which I start the server has fundamentally changed but is still only one command - I know I have to do "docker run" to start it, rather than "python run.py" or similar. In virtualenv I have to remember two commands; "workon bla" and "python run.py".

Regarding point 3, yes I think docker in production is ok, or soon will be :)

zigara3• 12 years ago

How about you use a simple virtualenv wrapper such as https://pypi.python.org/pypi/vex ?

Then you can easily type 'vex myenv python myapp.py', no need to spin up a linux container for simple development.

tbatterii• 12 years ago

how about one command...

$ /path/to/virtualenv/bin/python run.py

crdoconnor3• 12 years ago

That said, he made a good point about non-python dependencies.

Does he? I have about 5, all of which I can install with one line with apt-get. Only a few libraries have external dependencies anyway.

I could understand for projects/frameworks that require extensive specialized configuration/package installations that might interfere with other things on your system. You don't really have that problem with virtualenv, though. It's 90% isolated on it's own.

pnathan• 12 years ago

I have developed in Python for the past 4 years, give or take. Virtualenvs have, hands down, been one of the worst parts of the experience, without exception, and I can not recommend them.

(No, I won't write up an essay about why on HN. If you really want me to, shoot me an email and I'll write an essay about them).

mbreese2• 12 years ago

I've been doing this for a while longer (Python heavily for the past 7-ish years) and I've had a great experience working with virtualenvs...

So, I'd love to see that essay :)

stuaxo2• 12 years ago

This could be really useful for non-python webapps.

Gtk and other libraries for stuff like Sound haven't caught up to the virtualenv age + getting them to work can involve ugly hacks.

chanux2• 12 years ago

I see a lot of 'but why' questions in the thread. When I started to work with Docker for the very first time, I soon realized that it is going to be fantastic for setting up dev environments (I was not that in to VMs anyway).

I have put pretty complex setup at work on docker and it made things really simple for people who wants to set it up on their work laptop. Especially the new hires (oh and interns).

Of course Docker is more stuff to learn but when it's just a bunch of instructions to follow on a readme file they would just run those and have the system running (mostly without much trouble) and later figure out what this Docker thing really is, if they are in to it.

Using Docker as a Python Development Environment

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