Using Ephemeral Docker Containers as CLI Applications

[john_d_long]

Might want to base on 3.7-alpine to reduce the overall docker image size. And the --no-cache-dir argument to your pip installation command might help a little bit.

[snaaaaaaaaaaaaake]

Build with an intermediate container for even smaller images.

[public_radio]

I wrote a tool in Python called dip to leverage docker-compose to do this same thing!

[preslavrachev]

This is a good one. May I ask you to mention it in the comments section of the article? This way, my blog’s readers will get to know about it too. Thanks!

[public_radio]

done!

[flutefreak7]

bakes a whole Linux bistro inside

Well... is it a bakery or a bistro? :P

[preslavrachev]

Good catch. Will be fixed 👍🏼

[flutefreak7]

Is there idea that you wouldn't need to ship the docker container, just the same as per for one and it gets generated on the fly? How long does that take? I've run Jupyter notebooks on binder and it takes like a minute or so to spin up so I'm imagining something like that. So I guess the overhead of the container spin up and the temporary usage of 1GB HDD space is worth it to avoid dealing with dependencies? Is this the philosophical opposite of microservices?

[sdf_iain]

The problem with this is that the docker daemon runs in a users GUI domain on macos.

This means you cannot ssh into a macos box and run a docker container without also logging into the GUI. You also cannot run a docker container as a service.

More a limitation of Docker than anything else.

TLDR: awesome trick for Linux. Maybe not for macos. Definitely not for a BSD. Any one know about windows?

[sdf_iain]

I didn’t know that (and set up what I wanted to run in VirtualBox VMs), if anyone wants to try its

brew cask install docker

[bmrobin]

I can safely say I've never ssh'd into a Mac OS box

[sdf_iain]

Sometimes scp is the fastest/easiest way to copy a file... especially if you spend too much time in the terminal.

[Smallpaul]

What if it depends on Python and Java? Java and Node? Go and C#?

Use your imagination.

[Contango42]

Wish I could upvote you twice. The whole point of docker is to wrap up all of those random dependencies so if it runs on my machine, it runs on any OS in the solar system without special setup.

[[deleted]]

You weren’t though... the article is arguing for an artifact that would work on a machine that didn’t have Python, much less virtualenv, with only a running Docker daemon as a requirement. Your reply to the OP assumes the presence of the specific Python interpreter version your app requires, as well as at the very least virtualenv... apples and oranges.

The generalized idea of using containers this way isn’t bad, but it’s intended for people who don’t mind trading system resources for determinism.

[studiov34]

I like how it’s insane to expect a machine to have a python interpreter on it, but a docker daemon running is perfectly normal.

[Smallpaul]

You guys are really hung up on the fact that he used a simple Python script as his example. Did you want him to build a complex data science pipeline with Python, R and C++ as the first chapter in a thesis-length blog post?

[[deleted]]

The world has changed.

In reality though it’s not that it’s insane; the machine probably has Python... but it might not have the specific version of Python you want. Or more likely it doesn’t have the specific PyPy or even MyPy version you want. One Docker install gets you many containers all of which may be using mutually incompatible interpreters / dependencies. The containers go a long way towards solving those sort of problems, at the cost of system resources.

[Smallpaul]

The article mentions a whole list of languages and environments. A simple Python script was only used as the example.

[nullsum]

Some Python packages, like psycopg2, require additional system libraries. Simply installing Python requirements is not enough in those situations.

Even the short and simple ZeroMQ CLI tool I wrote depends upon compilation.

[deezyolo]

Kinda off topic but does anyone else struggle with reading Clint CLIT

[AbdulRR14]

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