Pipely

Build connected apps without the need to write a server. Pipely enables you to connect clients and exchange data with a server-client/client-client hybrid architecture. The Pipely server is a lightweight, concurrent SSE server with allows clients to created temporary channels which can be joined by other clients. The channels can be created with or without a password protection.

Getting started

In order to begin writing serverless connected apps you need to:

• Deploy a Pipely server
• Create/Join a channel
• Exchange data

Deploy a Pipely server

In order to setup a Pipely server run the following in a $GOPATH src/ directory:

$ git clone git@github.com:bene/pipely-server.git
$ cd pipely-server
$ docker build -t pipely/server .

After a successful build start a Docker container:

$ docker run --name="pipely-1" -p 6550:6550 --restart=always pipely/server

Create/Join a channel

Once a server is up and running you can subscribe with an EventSource or SSE client. This example uses the default JavaScript EventSource client, with is currently supported by Chrome, Firefox, Safari and Opera. Polyfills are available for Edge and IE.

const eventSource = new EventSource('//localhost:6550/subscribe?channelId=CHANNEL_ID&clientId=CLIENT_ID&password=CHANNEL_PASSWORD')

Parameter	Type	Criteria	Required
channelId	String	Twelve characters long	Yes
password	String	Only needed if the channel has or should have a password	No
clientId	String	Must be at least three characters long and has to be unique in channel	Yes

If a client connects to a non existent channel, the channel will be created, with or without a password, depending on the query. If the channel exists, the password has to be valid. When the last member of a channel disconnects, the channel will be destroyed by the server, and anyone can re-create it with a new password.

Exchange data

To exchange data, events are used. An event is just a JSON object with specific fields. In order to publish an event to a channel, a POST request has to be sent to the server, in this case cURL is used:

curl -X POST \
  http://localhost:6550/publish \
  -H 'Authorization: Password CHANNEL_PASSWORD' \
  -H 'Content-Type: application/json' \
  -d '{
	"channel_id":"CHANNEL_ID",
	"type": "EVENT_TYPE",
	"origin_id": "ORIGIN_ID",
	"payload": {
		"test":"Hello World!"
	}
}'

Request Headers:

Field	Type	Description	Value
Authorization	String	Needed if the channel has a password	Password CHANNEL_PASSWORD
Content-Type	String	Needed since the body is a JSON object	application/json

Request Body:

Field	Type	Criteria
channel_id	String	Twelve characters long
type	String	Must be at lease one character long
origin_id	String	Must be at least three characters long, should either be 'server' or a client id by a channel member
payload	JSON Object	Must be a valid JSON object or can be undefined

To receive data the SSE clients have to manage incoming messages:

eventSource.onmessage = (e) => {
    const data = JSON.parse(e.data);

    const eventType = data['type'];
    const originId = data['origin_id'];
    const payload = data['payload'];

    ...
}