I'm happy that it works for you, but many people have complex infrastructures that aren't easily deployed with virtualenv+apt-get alone.

I wish I could deploy our python apps with virtualenv alone, but before docker we ended up having to create our own deployment system to wrap the virtualenv with all the associated dependencies so it could be pushed to various environments in a deterministic manner.

>I'm happy that it works for you, but many people have complex infrastructures that aren't easily deployed with virtualenv+apt-get alone.

For your development environment? Seriously?

>I wish I could deploy our python apps with virtualenv alone

I thought this was about dev environments? For deployment (and testing deployment) I use a virtual machine too - vagrant/virtualbox + ansible. Yes, I wouldn't want to pollute my computer with that stuff either.

I wouldn't want to develop inside a virtual machine, though.

A previous python project I worked on had multiple independently developed services, sometimes with conflicting requirements. Production often separated these, but keeping staging and local development environments happy was a constant struggle.

I also like to make sure the devs are working with an environment that translates directly to production (docker makes this much easier now). I really don't enjoy sorting out a blob of code that only works with your specific local configuration:

- ok requires opencv (or other complicated dependency). No problem, that's already in production. - Oh it only builds against the 2.4.7.1 version you have on your machine. - Hmm, 2.4.7.1 has a bug when used with common_lib version X on distro Y - etc.

If it breaks it's essentially a bug in the kernel.

If you don't see benefits of virtualization then I guess there's no convincing you, and maybe you just really don't need them. But there are people who would benefit from virtualization but don't do it because of the costs of maintaining and running a full VM, and Docker can be a good solution for them.

Python has virtual environments already. I don't see any need to host it in a guest VM.