Socketeer is a socket server that listens for MongoDB events and broadcasts them to connected clients. It is built with Golang and uses the mongo-go-driver for listening to database events. It uses gorilla/websockets package for the websocket server.

go get github.com/darthsalad/socketeer

• Create a new Socketeer instance:

s, err := socketeer.NewSocketeer(mongodb_uri, db_name, collection_name)

• Start the Socketeer server for listening to events and dispatching them to connected clients through websockets:

s.Start(document_fields, server_url, server_endpoint)

• It starts the websocket server as well as the database listener synchronously. The document_fields parameter is a string array that specifies the fields to be returned in the ChangeStream cursor. The server_url and server_endpoint parameters are the url and endpoint of the websocket server respectively. For example:

s.Start([]string{"name", "email"}, "localhost:8080", "/ws")

• The Socketeer server can be stopped by calling the Stop() method:

s.Stop()

• The response format of the data from sockets is of the format map[string]string and then are Marshalled into JSON. For example:

var response = make(map[string]string)

• The fields are populated with the data from the database the fields are the ones specified in the document_fields parameter
• For Example:

fields := []string{"name", "email"}

response["name"] = "John Doe"
response["email"] = "johndoe@example"

data, err := json.Marshal(responseMap)

• This byte array is then sent to the client through the websocket connection.

• The client can then parse the data and use it as required. Example of received can be:

  {
    "name": "John Doe",
    "email": "johndoe@example"
  }

For a full example, check out the example directory. See this file.

// client/side/socket/example.js

const conn = new WebSocket("ws://localhost:8080/ws");
conn.onopen = () => {
  console.log("Connected to Socket server!");
};
conn.onmessage = (e) => {
  const data = JSON.parse(e.data);
  // do what you want with the data
};

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.

• Darthsalad