Overview

This interface implements the basic form of the tcp interface protocol.

Usage

Provides

By providing the tcp interface, your charm is providing a TCP endpoint.

Your charm need only to provide the port on which it is serving its service, as soon as the endpoint.{relation-name}.joined state is set:

@when('endpoint.tcp.joined')
def configure_tcp():
    tcp = endpoint_from_flag('endpoint.tcp.joined')
    tcp.configure(port=hookenv.config('port'))

Requires

By requiring the tcp interface, is consuming one or more TCP services.

This interface layer will set the following states, as appropriate:

• endpoint.{relation-name}.joined indicates that at least one service is connected. This state is automatically removed.
• endpoint.{relation-name}.update is set whenever a change happened. This is triggered when a providing charm sends new/updated info or when a relation departs. This state needs to be manually removed.

Use the tcp_services() method to return a list of available TCP services:

[
    {
        'service_name': name_of_service,
        'hosts': [
            'host': private_address_of_host,
            'port': port_for_host,
        ],                
    }
]

Authors

This software was created in the IDLab research group of Ghent University in Belgium. This software is used in Tengu, a project that aims to make experimenting with data frameworks and tools as easy as possible.

• Sander Borny sander.borny@ugent.be