gotell

gotell

Cloud Components for push notification service implemented using go

gotell is a set of components that can be used to implement a push notification service. The components support building stateless application running in PaaS, such as cloudfoundry.

gotell uses redis pub-sub in order to perform a stateless way of websocket notification across multiple instances of the app, especially when deployed in a PaaS.

Functionalities

• Push notification to websocket clients
• Websocket clients can connect to wss://gotellURL/ws/'clientid' and then any other application can do a https post to gotellURL/notify/'clientid' with body as the JSON {"message":"Value"} and the 'Value' content will be delivered to the client.
• The Value can be another JSON, but enclosed with in double quotes (as with string) and the doublequotes that are part of the value should be escaped (replace " with \" ).
• Examples:
  • { "message": "Hello from me"}
  • { "message": "{\"msg\":\"Hello from User1\"}"}
• APNS support
• Requires app cert and unencrypted key pem files.
  • The cert and key file name is read from the environment variable 'APNS_CERT' and 'APNS_KEY' respectively.
• Do http POST https://<gotellURL>/apns/<devicetoken> with header Content-Type : application/json and body as '{"message":"Message Value","badge":0,"sound":"default"}'
  • devicetoken should be the device token of the device to which the notification has to be sent.
  • Message Value can be another JSON,but enclosed with in double quotes (as with string) and the doublequotes that are part of the value should be escaped (replace " with " ).
  • The badge value has to be an integer and badge count set will be displayed in the app icon
  • The sound value can be any aiff file name or pass the string "default" for default notification sound.

To Do

• GCM support

#How to Use this library

Re-Requisite: Install Go

• cd to GOPATH
• Run the command 'go get github.com/jayaramsankara/gotell'
• Add the statement 'import "github.com/jayaramsankara/gotell"' in your main go file
• Initiate the notification server by invoking gotell.InitServer with appropriate params

Example

// Start the web socket server and wait in a loop

err := gotell.InitServer(httpHost, httpPort, redisOptions)

if err != nil {

	log.Println("Failed to initiate notification service.", err)
	
}

Example Application

gonotify.herokuapp.com