manage.get.gov/docs/operations/runbooks/update_python_dependencies.md

HOWTO Update Python Dependencies

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1. Check the Pipfile for pinned dependencies and manually adjust the version numbers

2. Run docker-compose stop to spin down the current containers and images so we can start afresh

3. Run

    cd src
    docker-compose run app bash -c "pipenv lock && pipenv requirements > requirements.txt"
   

   This will generate a new Pipfile.lock and create a new requirements.txt. It will not install anything.

   It is necessary to use bash -c because run pipenv requirements will not recognize that it is running non-interactively and will include garbage formatting characters.

   The requirements.txt is used by Cloud.gov. It is needed to work around a bug in the CloudFoundry buildpack version of Pipenv that breaks on installing from a git repository.

4. Run docker-compose build to build a new image for local development with the updated dependencies.

   The reason for de-coupling the build and lock steps is to increase consistency between builds--a run of build will always get exactly the dependencies listed in Pipfile.lock, nothing more, nothing less.