Plugins

[roaminro]

Brief description

This PR adds the ability for node operator to run addional microservices that can leverage the already established P2P network created for the blockchain:

• a new "flag" or yaml option called plugins was added, it accepts an array of strings.
• upon startup, the P2P service, for each plugin found in the flag plugins:
  • connects to the plugin's microservice via AMQP
  • once connected, sets up an AMQP broadcast handler that will listen to the topic plugin.PLUGIN_NAME
  • sets up a Gossip Manager that will listen to P2P messages gossiped on the topic plugin.PLUGIN_NAME
• gossiped P2P messages are not validated at the P2P microservice level, the data is simply passed onto the plugin microservice
• only messages that were sent by other peers are forwarded to a plugin

Limitations:

• libp2p does not propagate gossiped messages that are not handled by a node, meaning that a node running a plugin needs to be connected to other nodes that run the same plugin in order to receive P2P messages... (I asked the team behind the go-libp2p library and they told me you can tell a node to relay gossiped messages for a given topic, but you'll need to know the plugins' topics before turning on the node)

Additional changes:

• requires to add a new proto message in the Koinos RPC proto package, see this fork: https://github.com/roaminroe/koinos-proto/blob/plugins/koinos/rpc/plugin/plugin_rpc.proto

Checklist

• [ ] I have built this pull request locally
• [ ] I have ran the unit tests locally
• [ ] I have manually tested this pull request
• [ ] I have reviewed my pull request
• [ ] I have added any relevant tests

Demonstration

[roaminro]

opened a draft PR as there are no tests available for this new feature, might need to create a minimal "test plugin" that can be used the integration tests repository

[koinos-ci]

This pull request is stale because it has been open for 30 days with no activity.

[koinos-ci]

This pull request was closed because it has been inactive for 14 days since being marked as stale.