The Zetta Codebase

Here is a general run down of the Zetta codebase.

Zetta Codebase

Pre-work libraries

The bulk of zetta is created with libraries we've created ourselves. Here are the base libraries and orgs that you should look at and follow.

• Argo -> https://github.com/argo
  • argo/argo
  • argo/argo-resource
  • argo/argo-siren-formatter
• Medea -> https://github.com/medea
• Zetta -> https://github.com/zettajs -> There are many separate modules that are also baked into zetta.
• SPDY (not built by us)-> https://github.com/indutny/node-spdy
• WS (not built by us)-> https://github.com/websockets/ws

/

• zetta.js -> Main zetta class exposed for use in scripts
• zetta_runtime.js -> File that exposes everything for developers to consume

/bin

Directory that stores code coverage scripts and version release scripts.

/lib

Directory that holds the bulk of the zetta implementation.

• device_registry.js -> Leveldb based registry implementation for storing devices that have been exposed by the zetta server.
• event_broker.js -> Centralized class for gathering subscriptions from clients and apps and connecting those subscriptions to the appropriate zetta node.
• event_socket.js -> Class that sends websocket stream messages
• http_scout.js -> Vestigial
• http_server.js -> The base http server that wires up the API and accepts websocket connections
• logger.js -> Base logger class. Exposes logging functionality, and hooks to override behavior.
• peer_client.js -> Establishes connections from a hub zetta node to a cloud zetta node.
• peer_registry.js -> Leveldb based registry that holds information on peers that have been connected to.
• peer_socket.js -> Recieves connections from hub zetta nodes.
• pubsub_service.js -> Centralized places where events are gathered on a zetta server. Streams, server events, and transitions go through this to be propogated to objects in js, or to other zetta nodes via event broker.
• query.js -> Vestigial
• query_topic.js -> Parses device query stream topics
• registration_resource.js -> Vestigial
• registry.js -> Base class for the registries. Flat file leveldb. Subclass this for additional registries.
• runtime.js -> Essentially this is the server variable passed into apps. Allows for device queries and other hooks into zetta that aren't exposed in the server file.
• spdy_agent.js -> Subclasses default http agent in nodejs to expose the spdy socket.
• virtual_device.js -> Abstraction for devices that are queried from another server.
• web_socket.js -> Basic websocket implementation to move away from WS eventually.

/test

Holds our unit tests. They are written in Mocha.

/lib/api_formats/siren

Holds our API object templates. Uses the argo-formatter module

• device.siren.js -> Device template serves the /servers/<id>/devices/<deviceId> route
• devices.siren.js -> Device list template serves the /servers/<id>/devices route
• metadata.siren.js -> Metadata api to describe device models /servers/<id>/devices/<type>/meta
• server.siren.js -> Server template serves the /servers/<id> route
• type.siren.js ->

/lib/api_resources

Holds our API resource business logic. Uses the argo-resource module

• devices.js -> Devices route handler
• peer_management.js -> Peer management route handler
• root.js -> Root route handler
• servers.js -> Servers route handler