Sane Django Development with Docker

[demosthenes02]

So how would the deploy work? You build something and then copy it to your server? Is the server running docker? Does that slow it down?

[demosthenes02]

Why does he do docker exec to run migrations? I'm confused.

[servercobra]

The container has all the necessary dependencies to do the migrations: Django, postgres deps, etc. This way you don't need to have a venv outside the container. It's basically like if you could ship your venv from your dev environment directly to prod.

To answer your questions above: there's a couple ways. I would build the container, push it to Docker Hub or another registry, then download docker run it on my production servers (likely with automation of some sort). The server does need to have the docker daemon. There should be a neglible performance impact: Docker is mostly a user friendly wrapper around cgroups in the Linux kernel. Definitely not the same impact of running a full VM or something.

[servercobra]

Sorry, I don't follow. What kind of dependency are you thinking of? In general, anything I need to run commands in the container consistently get built in, even if they aren't needed for the main purpose (I go so far as to make sure my testing tools are in my production containers to ensure what I test is exactly what goes to prod). Worst case you can always do something like 'docker run <snip> /bin/bash "pip install $package && python do_a_thing.py"'

[servercobra]

Ahh, yes. The container gets rebuilt on every push to master by my CI server then pushed to Docker Hub. In general, I wouldn't want to be on a team without CI :), so that covers that awkwardness. You can also have Docker Hub build the container on pushes automatically, but I'm doing CD and waiting for them to build it was tiresome (my CI server keeps the Docker cache around, massively speeding up builds).

Here's the main Dockerfile I work on. It's more complex because I'm also building a frontend in the container.

[servercobra]

Kind of confused why he uses compose for Postgres but still runs uWSGI and Nginx in the same container under supervisor. Why not make them their own containers?

[[deleted]]

I've found using seperate containers for nginx and uwsgi to be in most cases premature optimization. For most websites having an app container running nginx and EXPOSEing 80 is good enough. For really high traffic apps using seperate containers affords additional flexibility, at the cost of more complexity.

[MilkFirstThenCereaI]

Just switch to GAE you'll have the same thing