datagov-deploy-python-app

Deploys a Python based application in 12 factor fashion.

• Creates a system user to own the application.
• Each deployment is isolated in its own directory with its own virtualenv.
• Makes secrets available in $APP_DEPLOYMENT_DIR/secrets/env.
• Application configuration and installation is done first, before linking (making the deployment active).
• Old deployments are removed.
• (Optionally) installs a supervisor configuration.
• (Optionally) installs a crontab.

This role is influenced by Ansistrano.

Usage

Dependencies

Include these roles in your requirements.yml.

• avanov.pyenv

Use the role in your playbook:

---
- name: install a python app
  roles:
    - role: gsa.datagov-deploy-python-app
      vars:
        python_app_user: myapp

Variables

python_app_user string required

The OS user to create and install the app under. This is also used as the application name.

python_app_git_repo string required

The git URL to your app repository.

python_app_version string (default: master)

The tag, branch, or commit to clone your application from.

python_app_deploy_version string

The string to use for the deployment version. This is usually a timestamp so each deployment is uniq. It's important that deploy versions sort chronologically so that cleanup removes the oldest deploys by sorting by the deployment version.

python_app_home string (default: /home/{{ python_app_user }})

Directory to create for the Python app user's home directory. This is where application deployments will be installed.

python_app_python_version string (default: "3.6.8")

The version of Python to install.

python_app_requirements_txt string (default: requirements.txt)

The relative path to your requirements.txt from your application source.

python_app_deployments_to_retain number (default: 1)

The number of previous deployments to retain. Set to 0 to retain all old deployments.

python_app_os_packages list (default: [])

List of OS packages that are needed by your application.

python_app_supervisor_programs list (default: [])

List of supervisor programs to restart after a deployment.

Development

Requirements

• Docker
• Pipenv

Setup

Pipenv creates a virtualenv for you and installs the python dependencies.

$ pipenv install --dev

Then you can run commands with pipenv.

$ pipenv run molecule converge

Or, you can activate the virtualenv in your shell so you don't have to run pipenv all the time.

$ pipenv shell

Run the tests

Run the tests with molecule.

$ pipenv run molecule test --all

If you're new to molecule, see our wiki for a quick primer.

Contributing

See CONTRIBUTING for additional information.

Public domain

This project is in the worldwide public domain. As stated in CONTRIBUTING:

This project is in the public domain within the United States, and copyright and related rights in the work worldwide are waived through the CC0 1.0 Universal public domain dedication.

All contributions to this project will be released under the CC0 dedication. By submitting a pull request, you are agreeing to comply with this waiver of copyright interest.