Deploying to PyPI with sr.ht

2019-04-10

I recently started to use builds.sr.ht (part of the sourcehut.org stack) to run continuous integration for a small python project. The project eventually reached a releasable state, and I wanted to automate that task. I had never deployed a project to PyPI, but after learning more about the builds.sr.ht CI system (specifically the ability to use secrets) I decided to give it a shot. Running simple unit tests with builds.sr.ht was super easy, so I hoped adding PyPI deployment would be pretty simple -- it definitely is.

Setting up your secret PyPI credentials

First create a temporary file (that will be our pypirc file, read more here if this doesn't sound familiar) with the following contents:

[pypi]
username = your_username
password = your_password

Travel to https://builds.sr.ht/secrets and add it. Just give it a name, select the File type, make the path ~/.pypirc, make the permission mode 600, and upload it (get rid of the copy on your local file system if you don't want to keep a local ~/.pypirc).

The build manifest

In the tasks section of the build manifest we're just going to add a deploy step. In the build step, where I setup my python environment, I make sure to install twine (necessary for uploading to PyPI).

image: ...
packages:
  - ...
sources:
  - ...
secrets:
  - abcdefgh-ijkl-lmno-pqrx-tuvwxyz12345
tasks:
  - build: |
      python -m venv cienv
      source cienv/bin/activate
      pip install pytest twine setuptools wheel
      cd myproject
      pip install .
  - test: |
      ...
  - deploy: |
      source cienv/bin/activate
      cd myproject
      python setup.py sdist bdist_wheel
      python .ci-scripts/srht-pypi.py

For this example I'm building both a source distribution (sdist) and a wheel (bdist_wheel) for the toy project¹. In the repository I have a directory called .ci-scripts with a script to handle the PyPI upload. The script ensures that I only upload to PyPI if the repository git hash is on a tag, and the name of the tag is the same as the version of the python project (the versions and tags are formatted X.Y.Z). Here are the contents of that script:

import subprocess
import myproject.version
import sys

def main():
    res = subprocess.run(["git", "describe"], stdout=subprocess.PIPE)
    describe_out = res.stdout.decode("utf-8").split("-")
    print(describe_out)
    if len(describe_out) > 1:
        return 0
    elif myproject.version.version == describe_out[0].strip():
        res = subprocess.run("twine upload dist/*", shell=True)
        return res.returncode
    else:
        return 0;

if __name__ == "__main__":
    main()