notifications-utils

This is the shared Python code for the Notiy.gov applications. It standardizes how to do logging, rendering message templates, parsing spreadsheets, talking to external services, and more.

Our other repositories are:

Before You Start

You will need the following items:

Admin priviliges and SSH access on your machine; you may need to work with your organization's IT support staff if you're not sure or don't currently have this access.

NOTE: If you've set up the API project, you will have most of the project prerequisites installed already.

These instructions are modified and slightly simplified from the Notify.gov API set up instructions; they're tailored specifically for this project.

Local Environment Setup

This project is currently set up as a Python 3.12.x-based module.

These instructions will walk you through how to set your machine up with all of the required tools for this project.

Project Pre-Requisite Setup

On MacOS, using Homebrew for package management is highly recommended. This helps avoid some known installation issues. Start by following the installation instructions on the Homebrew homepage.

Note: You will also need Xcode or the Xcode Command Line Tools installed. The quickest way to do this is is by installing the command line tools in the shell:

xcode-select –-install

Homebrew Setup

If this is your first time installing Homebrew on your machine, you may need to add its binaries to your system's $PATH environment variable so that you can use the brew command. Try running brew help to see if Homebrew is recognized and runs properly. If that fails, then you'll need to add a configuration line to wherever your $PATH environment variable is set.

Your system $PATH environment variable is likely set in one of these locations:

For BASH shells:

~/.bashrc
~/.bash_profile
~/.profile

For ZSH shells:

~/.zshrc
~/.zprofile

There may be different files that you need to modify for other shell environments.

Which file you need to modify depends on whether or not you are running an interactive shell or a login shell (see this Stack Overflow post for an explanation of the differences). If you're still not sure, please ask the team for help!

Once you determine which file you'll need to modify, add these lines before any lines that add or modify the $PATH environment variable; near or at the top of the file is appropriate:

# Homebrew setup
eval "$(/opt/homebrew/bin/brew shellenv)"

This will make sure Homebrew gets setup correctly. Once you make these changes, either start a new shell session or source the file (source ~/.FILE-YOU-MODIFIED) you modified to have your system recognize the changes.

Verify that Homebrew is now working by trying to run brew help again.

System-Level Package Installation

There are several packages you will need to install for your system in order to get the app running (and these are good to have in general for any software development).

Start off with these packages since they're quick and don't require additional configuration after installation to get working out of the box:

jq - for working with JSON in the command line
git - for version control management
vim - for editing files more easily in the command line
wget - for retrieving files in the command line

You can install them by running the following:

brew install jq git vim wget

Python Installation

Now we're going to install a tool to help us manage Python versions and virtual environments on our system. First, we'll install pyenv and one of its plugins, pyenv-virtualenv, with Homebrew:

brew install pyenv pyenv-virtualenv

When these finish installing, you'll need to make another adjustment in the file that you adjusted for your $PATH environment variable and Homebrew's setup. Open the file, and add these lines to it:

# pyenv setup
export PYENV_ROOT="$HOME/.pyenv"
command -v pyenv >/dev/null || export PATH="$PYENV_ROOT/bin:$PATH"
eval "$(pyenv init -)"
eval "$(pyenv virtualenv-init -)"

Once again, start a new shell session or source the file in your current shell session to make the changes take effect.

Now we're ready to install the Python version we need with pyenv, like so:

pyenv install 3.12

This will install the latest version of Python 3.12.

NOTE: This project currently runs on Python 3.12.x.

Python Dependency Installation

Lastly, we need to install the tool we use to manage Python dependencies within the project, which is poetry.

Visit the official installer instructions page and follow the steps to install Poetry directly with the script.

This will ensure poetry doesn't conflict with any project virtual environments and can update itself properly.

First-Time Project Setup

Once all of pre-requisites for the project are installed and you have a cloud.gov account, you can now set up the API project and get things running locally!

First, clone the repository in the directory of your choosing on your machine:

git clone git@github.com:GSA/notifications-utils.git

Now go into the project directory (notifications-utils by default), create a virtual environment, and set the local Python version to point to the virtual environment (assumes version Python 3.12.2 is what is installed on your machine):

cd notifications-utils
pyenv virtualenv 3.12.2 notify-utils
pyenv local notify-utils

If you're not sure which version of Python was installed with pyenv, you can check by running pyenv versions and it'll list everything available currently.

Upgrading Python in existing projects

If you're upgrading an existing project to a newer version of Python, you can follow these steps to get yourself up-to-date.

First, use pyenv to install the newer version of Python you'd like to use; we'll use 3.12 in our example here since we recently upgraded to this version:

pyenv install 3.12

Next, delete the virtual environment you previously had set up. If you followed the instructions above with the first-time set up, you can do this with pyenv:

pyenv virtualenv-delete notify-utils

Now, make sure you are in your project directory and recreate the same virtual environment with the newer version of Python you just installed:

cd notifications-utils
pyenv virtualenv 3.12.2 notify-utils
pyenv local notify-utils

At this point, proceed with the rest of the instructions here in the README and you'll be set with an upgraded version of Python.

If you're not sure about the details of your current virtual environment, you can run poetry env info to get more information. If you've been using pyenv for everything, you can also see all available virtual environments with pyenv virtualenvs.

Running the Project and Routine Maintenance

The first time you run the project you'll need to run the project setup from the root project directory:

make bootstrap

This command is handled by the Makefile file in the root project directory, as are a few others.

NOTE: You'll want to occasionally run make bootstrap to keep your project up-to-date, especially when there are dependency updates.

Testing the library

You can run tests for this library with the following command:

make test

Git Hooks

We're using pre-commit to manage hooks in order to automate common tasks or easily-missed cleanup. It's installed as part of make bootstrap and is limited to this project's virtualenv.

To run the hooks in advance of a git operation, use poetry run pre-commit run. For running across the whole codebase (useful after adding a new hook), use poetry run pre-commit run --all-files.

The configuration is stored in .pre-commit-config.yaml. In that config, there are links to the repos from which the hooks are pulled, so hop through there if ou want a detailed description of what each one is doing.

We do not maintain any hooks in this repository.

To update the version of this library

We follow the Semantic Versioning principles:

Given a version number MAJOR.MINOR.PATCH, increment the:

MAJOR version when you make incompatible API changes MINOR version when you add functionality in a backward compatible manner PATCH version when you make backward compatible bug fixes

You'll need to modify two files with matching version numbers:

Line 3 in pyproject.toml
Line 11 in setup.py (this will be deprecated in the near future)

Once you finish making these adjustments, commit the changes and create a new Pull Request (or add them to an existing one) for review and acceptance. This will make the new version available for the other repos to consume.

Python Dependency Management

We're using Poetry for managing our Python dependencies and local virtual environments. When it comes to managing the Python dependencies, there are a couple of things to bear in mind.

For situations where you manually manipulate the pyproject.toml file, you should use the make py-lock command to sync the poetry.lock file. This will ensure that you don't inadvertently bring in other transitive dependency updates that have not been fully tested with the project yet.

If you're just trying to update a dependency to a newer (or the latest) version, you should let Poetry take care of that for you by running the following:

poetry update <dependency> [<dependency>...]

You can specify more than one dependency together. With this command, Poetry will do the following for you:

Find the latest compatible version(s) of the specified dependency/dependencies
Install the new versions
Update and sync the poetry.lock file

In either situation, once you are finished and have verified the dependency changes are working, please be sure to commit both the pyproject.toml and poetry.lock files.

Known Installation Issues

Python Installation Errors

On M1 Macs, if you get a fatal error: 'Python.h' file not found message, try a different method of installing Python. The recommended approach is to use pyenv, as noted above in the installation instructions.

If you're using PyCharm for Python development, we've noticed some quirkiness with the IDE and the interaction between Poetry and virtual environment management that could cause a variety of problems to come up during project setup and dependency management. Other tools, such as Visual Studio Code, have proven to be a smoother experience for folks.

License && public domain

Work in commit a86d365 is licensed by the UK government under the MIT license. Work after that commit is in the worldwide public domain. See LICENSE.md for more information.

Contributing

As stated in CONTRIBUTING.md, 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.