Elixir Firestore Wrapper

An abstraction over Google's Firestore API for convenience and configurability, providing you with the following capabilities:

• Defining Firestore database configs, which can be specific to each OTP application in an Elixir umbrella project.
• A configurable Repo module that can be used to conveniently run Firestore queries.
• Setting an HTTP adapter of your choice to be used in Tesla's client.
• Configuring connection pool sizes for applicable HTTP adapters.
• Support for encoding/decoding between Google's Firestore API and Elixir native types.

TODO:

• Support Firestore structured query semantics.
• Connection pool initialization.

Installation

The package can be installed by adding firestore to your list of dependencies in mix.exs:

def deps do
  [
    {:firestore, git: "https://github.com/Userpilot/elixir-firestore.git", ref: "{{COMMIT_HASH}}"}
  ]
end

Include the Firestore.Repo module in your application, you can put the use macro in your app's Repo module:

defmodule MyApp.Firestore.Repo do
  use Firestore.Repo,
    otp_app: :my_app,
    tesla_adapter: :hackney,
    pool_size: 50,
    read_only: false
end

Options:

• :tesla_adapter: This application uses Tesla HTTP client, which supports multiple to process requests. Use one of the following supported values [:httpc, :hackney, :ibrowse, :gun, :mint, :finch]

• :pool_size: If the adapter supports pooling, you can tune its size depending on expected throughput. Note that configurable pool sizing is only supported for :hackney and :ibrowse HTTP adapters. Note that pooling is only supported for :hackney and :ibrowse HTTP adapters. You can set this to nil to disable it, or if the adapter has no support for configurability.

• :read_only: If true, it will not include any write operation related functions in the module.

Then, add the appropriate Google Service Account credentials in your config file:

config :my_app, MyApp.Firestore.Repo,
  project_id: System.fetch_env!("FIRESTORE_PROJECT_ID"),
  private_key_id: System.fetch_env!("FIRESTORE_PRIVATE_KEY_ID"),
  private_key: System.fetch_env!("FIRESTORE_PRIVATE_KEY"),
  client_email: System.fetch_env!("FIRESTORE_CLIENT_EMAIL"),
  client_id: System.fetch_env!("FIRESTORE_CLIENT_ID"),
  auth_uri: System.fetch_env!("FIRESTORE_AUTH_URI"),
  token_uri: System.fetch_env!("FIRESTORE_TOKEN_URI"),
  auth_provider_x509_cert_url: System.fetch_env!("FIRESTORE_AUTH_PROVIDER_X509_CERT_URL"),
  client_x509_cert_url: System.fetch_env!("FIRESTORE_CLIENT_X509_CERT_URL"),
  url: System.fetch_env!("FIRESTORE_URL")

Finally you need to initialize the Firestore instance in your application's supervision tree:

children = [
  # ...
  {Firestore, MyApp.Firestore.Repo.config()},
  # ...
]

Usage (TODO)