Contributing

Contributions are always welcome!

Setup

This section contains instructions for creating a local development environment for the EctoPGMQ application.

Environment Variables

In order to run the project we must first setup some environment variables. These environment variables should be stored in a file named .envrc.

The necessary environment variables aren't actually secrets and can just be copied from .envrc.example:

cp .envrc.example .envrc

Below are a few tools that be used to source environment variables:

Mise (Preferred)

If you have mise installed, environment variables can be sourced with the following command:

mise trust

direnv

If you have direnv installed, environment variables can be sourced with the following command:

direnv allow .

Updates to the .envrc file will not take effect until the above command is run again.

External Services

As one would expect, this project requires a PostgreSQL instance with certain extensions installed. By default, we create a custom docker image and run a containerized version of this service to make local development more ergonomic. The configuration for this container can be found in the docker-compose.yml file.

Below are a few tools that can be used to run containers:

Docker

If you have Docker installed, the containers can be run with the following command:

docker compose up

Podman

If you have Podman installed, the containers can be run with the following command:

podman compose up

OrbStack

If you have OrbStack installed, the containers can be run with the following command:

docker compose up

Regardless of what tool you use to run the container, you should see a message like this when everything is up and running:

All services started and healthy!

Alternatively, while the project is set up to work with the aforementioned docker image, any Postgres instance can be used so long as the following extensions are available:

• pg_partman
• pgmq

The ECTO_PGMQ_POSTGRES_URL environment variable will just need to be updated accordingly.

Erlang and Elixir

This project is written almost entirely in Elixir but, since Elixir is built on top of Erlang, we need both languages installed.

The specific language versions used by the project can be found in the .tool-versions file.

Below are a few tools that can be used to manage language versions:

Mise (Preferred)

If you have mise installed, the language versions from the .tool-versions file can be installed with the following commands:

mise trust
mise install

asdf

If you're using asdf, you first need to install the language plugins:

asdf plugin add erlang
asdf plugin add elixir

Once you have the plugins installed, the language versions from the .tool-versions file can be installed with the following command:

asdf install

If the above command fails to install a language version, you may need to troubleshoot using the corresponding plugin's documentation:

• Erlang plugin
• Elixir plugin

Once Elixir and Erlang are installed, we can install their respective package managers if they aren't already available:

mix local.hex --if-missing --force
mix local.rebar --if-missing --force

Application

Once our environment variables are set, Postgres is running, and the necessary languages are installed, we can use the following command to install the project dependencies:

mix deps.get

From there, the application can be started in "REPL" mode with the following command:

iex -S mix

Testing

Tests can be run locally with the following command:

mix test

The CI workflow runs tests but also includes a few additional checks. This process can be run locally with the following command:

mix ci

Documentation

This project's documentation can be generated locally with the following command:

mix docs

The generated documentation can be viewed in a browser with the following command:

open doc/index.html

Debugging

You can optionally interact with the PostgreSQL container using psql. This tool is available if you've installed PostgreSQL.

Using psql, you can open a SQL terminal with the following command:

# Password is "ecto_pgmq"
psql -h localhost -p 5432 -U ecto_pgmq -d ecto_pgmq

Alternatively, if psql is not available, and you're running a Postgres container, you can execute the above command inside of the container to open a SQL terminal. The exact command is dependent on the tool you're using to run the containers, but here is an example:

# Find the Postgres container name/ID
docker ps

# Replace "ecto_pgmq-postgres" with the container name/ID
docker exec -it ecto_pgmq-postgres psql -U ecto_pgmq -d ecto_pgmq

Pull Request Process

Before submitting a pull request, make sure that:

1. The CI process is passing locally
2. Any relevant documentation is updated
3. The pull request description contains adequate context for a reviewer

Potential Future Enhancements

Itching to contribute but not sure where to start? Here's a list of potential enhancements that could benefit the application:

• Investigate adding a notion of a worker and leveraging it to limit the number of active consumers

• Investigate adding a scheduled job framework (maybe on top of pg_cron)

• Update the PGMQ extension to fix SQL-based installation failures

Code of Conduct

Our Pledge

In the interest of fostering an open and welcoming environment, we as contributors and maintainers pledge to making participation in our project and our community a harassment-free experience for everyone, regardless of age, body size, disability, ethnicity, gender identity and expression, level of experience, nationality, personal appearance, race, religion, or sexual identity and orientation.

Our Standards

Examples of behavior that contributes to creating a positive environment include:

• Using welcoming and inclusive language
• Being respectful of differing viewpoints and experiences
• Gracefully accepting constructive criticism
• Focusing on what is best for the community
• Showing empathy towards other community members

Examples of unacceptable behavior by participants include:

• The use of sexualized language or imagery and unwelcome sexual attention or advances
• Trolling, insulting/derogatory comments, and personal or political attacks
• Public or private harassment
• Publishing others' private information, such as a physical or electronic address, without explicit permission
• Other conduct which could reasonably be considered inappropriate in a professional setting

Our Responsibilities

Project maintainers are responsible for clarifying the standards of acceptable behavior and are expected to take appropriate and fair corrective action in response to any instances of unacceptable behavior.

Project maintainers have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct, or to ban temporarily or permanently any contributor for other behaviors that they deem inappropriate, threatening, offensive, or harmful.

Scope

This Code of Conduct applies both within project spaces and in public spaces when an individual is representing the project or its community. Examples of representing a project or community include using an official project e-mail address, posting via an official social media account, or acting as an appointed representative at an online or offline event. Representation of a project may be further defined and clarified by project maintainers.

Enforcement

Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting the project owner at gordonwoolbert3@gmail.com. All complaints will be reviewed and investigated and will result in a response that is deemed necessary and appropriate to the circumstances. The project team is obligated to maintain confidentiality with regard to the reporter of an incident. Further details of specific enforcement policies may be posted separately.

Project maintainers who do not follow or enforce the Code of Conduct in good faith may face temporary or permanent repercussions as determined by other members of the project's leadership.

Attribution

This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4, available at [http://contributor-covenant.org/version/1/4][version]