Tagged Connection

The files required for this example are:

• app_v1.py
• app_v2.py
• peer1.py
• peer2.py
• peer3.py

app_v1.py

# imports
import os

# configure our net configuration with a group identifier
os.environ['NET_GROUP'] = 'app_v1'

# net imports
import net


# application code version 1
@net.connect("myTaggedFunction")  # <- this can be any value.
def connected_function(message):
    """
    This will return the message with the " Version 1" appended to the end.
    """
    return message + ' Version 1'

app_v2.py

# imports
import os

# configure our net configuration with a group identifier
os.environ['NET_GROUP'] = 'app_v2'

# net imports
import net


# application code version 2
@net.connect("myTaggedFunction")
def connected_function(message):
    """
    This will return the message with the " Version 2" appended to the end.
    """
    return message + ' Version 2'

peer1.py

# Importing the application code will automatically launch the peer and begin
# listening for connection requests as well as set up the connection registry.
import app_v1

if __name__ == '__main__':
    # enter an endless loop so the peer will listen.
    while 1:
        pass

peer2.py

# Importing the application code will automatically launch the peer and begin
# listening for connection requests as well as set up the connection registry.
import app_v2

if __name__ == '__main__':
    # enter an endless loop so the peer will listen.
    while 1:
        pass

peer3.py

# net imports
import net

# This version of the peer will run the latest version of the
import app_v2


if __name__ == '__main__':

    all_app_peers = net.peers(groups=['app_v1', 'app_v2'], on_host=True)
    # First we need to grab the to running peers on our local host in both the
    # app_v1 and app_v2 groups. This will give us a dict laid out as follows.
    # {
    #       'peers': {
    #           peer1_id: info,
    #           peer2_id: info,
    #       },
    #       app_v1: [
    #           peer1_id
    #       ],
    #       app_v2: [
    #           peer2_id
    #       ]
    # }
    # This will allow us to better access the peers. You can grab a peer
    # directly of the dictionary OR get the group which has a list of all the
    # peer_ids that belong to it. Then use that list of peers to gran the
    # information.

    app_v1_peer = all_app_peers['app_v1'][0]
    # Lets grab the first peer that is using the app_v1 api and execute our
    # tagged function

    response = app_v2.connected_function("My Message!", peer=app_v1_peer)
    print(response)
    # This will result with "My Message! Version 1". Which shows that this new
    # api_v2 can still request a tagged version on an older platform.

    app_v2_peer = all_app_peers['app_v2'][0]
    # Lets grab the first peer that is using the app_v2 api and execute our
    # tagged function

    response = app_v2.connected_function("My Message!", peer=app_v2_peer)
    print(response)
    # This will result with "My Message! Version 2". Which is the latest version
    # of the api.