python-repos-ide-setup.md

General

If not using VS Code, or if you do not want to use a devcontainer, refer to the general local setup instructions in Python Repos Setup

Dev Container

The python repos (still a WIP to roll out to all repos at time of writing 15/07/24) contain a vs code dev container specification in ./.devcontainer/python/devcontainer.json. When used through VS code it provides:

• All the python dependencies for each service pre-installed For repos with a DB, it also contains:
• The postgres cmd client psql
• A standalone postgres instance, accessible from the dev container at <service>>-db:5432

See confluence for more discussion on dev containers and details of the basic setup.

Local Setup - VS Code

• Clone the repo into eg. funding-service-design-fund-store
• Open the folder funding-service-design-fund-store
• Use the command pallette (cmd + shift + P) and select 'Dev Containers: Reopen folder in container' (VS Code may prompt you for this on its own - it does the same thing)
• You are now in the dev container with all dependencies installed, and useful VS code extensions.
• There may be a delay in all the extensions (eg. unit testing) being available while it installs them in the container. This only happens the first time (or if you change container config and rebuild).
• You can now start the app in the usual way from the terminal inside the container with eg. flask run or run unit tests using the vs code extension or run pytest on the command line.
• This devcontainer also contains the dependencies and plugins needed for Pre-Commit as detailed below, but you still need to run pre-commit install.
• Git is accessible from with this container and should work with the vs code extension as usual.

Files involved

• .devcontainer Contains the vs code configuration for the container, such as which docker compose files to reference, and what extensions to install in the container.

• docker-compose.yml Details of the containers that are needed to develop this app. For fund-store it uses Dockerfile and a posgtres image.

• Dockerfile Details of the image to use for the dev container, under the stage <app-name>-dev.

• [Optional] compose.override.yml Allows overriding of properties such as exposed ports, or adding environment variables to the containers listed in docker-compose.yml. eg. If you want the postgres instance to be accessible from your local machine you could add the following to this file:

  services:
  fund-store-db:
      ports:
      - 5433:5432
  

  This will expose that postgres instance on port 5433 so you could connect a local psql client to it at localhost:5432

  If using this, add an additional item to the dockerComposeFile array in devcontainer.json pointing to this overrides file.

Pre-Commit

Each repo contains a .pre-commit-config.yaml which all developers should use to check styles etc before pushing changes.

Run the following while in your virtual enviroment:

    pip install pre-commit black

    pre-commit install

Once the above is done you will have autoformatting and pep8 compliance built into your workflow. You will be notified of any pep8 errors during commits.

Setup Flake8 linting

Each repo contains a pyproject.toml. This is a single lint configuration file for all the lint tools (flake8, black) used. By default, flake8 doesn't recognise .toml config files, so we use a flake8 plugin Flake8-pyproject(more details). To install it run the below command

    pip install Flake8-pyproject

For convenience, this is also included in the requirements-dev.in set of dependencies. For VS Code IDE users, once Flake8-pyproject is installed, the flake8 extension automatically applies configuration from pyproject.toml file.

detect-secrets hook

We use this pre-commit hook to prevent new secrets from entering the code base.(For more info: https://github.com/Yelp/detect-secrets)

• If the hook detects false positives, mark with an inline pragma: allowlist secret comment to ignore it.