[svieira]

Back when I was doing Python deployments (~2009-2013) I was:

* Downloading any new dependencies to a cached folder on the server (this was before wheels had really taken off) * Running pip install -r requirements.txt from that cached folder into a new virtual environment for that deployment (`/opt/company/app-name/YYYY-MM-DD-HH-MM-SS`) * Switching a symlink (`/some/path/app-name`) to point at the latest virtual env. * Running a graceful restart of Apache.

Fast, zero downtime deployments, multiple times a day, and if anything failed, the build simply didn't go out and I'd try again after fixing the issue. Rollbacks were also very easy (just switch the symlink back and restart Apache again).

These days the things I'd definitely change would be:

* Use a local PyPi rather than a per-server cache * Use wheels wherever possible to avoid re-compilation on the servers.

Things I would consider:

* Packaging (deb / fat-package / docker) to avoid having any extra work done over per-machine + easy promotions from one environment to the next.

[s_kilk]

I built a system that did something very like this at a previous employer. We got really quick (mostly) atomic deployments which could be rolled-back instantly with one command.

Even at the time I thought Docker would be a great solution to the problem, but the organization was vehemently against using modern tech to manage servers and deployments, so I ended up writing that tool in bash instead. Good times.

[thraxil]

This is basically how we still do it (with nginx + gunicorn rather than apache). Wheels (and recent setuptools/pip versions that build and cache them automatically) just made the build step significantly faster (lxml, argh).

We're moving to the Docker approach, which is really nice, but it does change the shape of the whole deploy pipeline, so it's going to take some time.

[crdoconnor]

This is exactly what I do.

>Use a local PyPi rather than a per-server cache

I stil prefer a per-server cache. A local pypi is another piece of infrastructure you need to keep alive. You don't have to worry about the uptime of an rsync playbook.