Every 10s the server will fetch new prices from cryptocompare through apis with Info module, which lives in a process aside from the main process.

First, it will get the coinList, which contains all the available coins. Then, we will select the first 20 coins per the SortOrder and fetch their prices. Finally, new prices will be broadcasted to the browser.

Email will be sent to the subscriber whenever the prices of the monitored coins lift above limit_high or drop down below limit_low. This will require checking through the coins table, which records the users' monitoring coins.

• Invoke

  Email Service is provided through a stand-alone process, use GenServer.cast(Email, {:send_email, prices}) to invoke. Every time new prices are fetched, the Info process will invoke email sending service, ie., every 10s by far.

• State

  The state of Email process is a map %{coinid => last_send_time}, and current checking time is 1h (3600s). If the interval between last send time and now is less than 1h, email won't be sent.

To start your Phoenix server:

• Install dependencies with mix deps.get
• Create and migrate your database with mix ecto.create && mix ecto.migrate
• Install Node.js dependencies with cd assets && npm install
• Load API Key: source .env (API keys is not on github)
• Start Phoenix endpoint with mix phx.server

• Google Credential Configuration

  Create credential, get Client ID and Client secret, and set corresponding env variables (can be done by scripts). Set up Ueberauth in config.exs, read configurations from System.env.

• HTTPS Setting

  Use certbot to auto-configure the config file, and use Redirect strategy for http request (due to the callback stuff).

• Nginx proxy Setting

  Since nginx proxy_pass will overwrite the request (host will be localhost and the port will be the running port), we need to add the line proxy_set_header Host $host:80 to restore the origin request. Ueberauth will read scheme, host and port from the Plug.Conn struct, thus don't forget to confirm the google redirect uris containing http://your.domain/auth/google/callback.

The latest Chrome

• Special thanks to CryptoCompare for providing the awesome apis.

• Special thanks to José Valim for solutions of scheduling works in phoenix