Skip to main content

Registry Svc

The registry service is designed to maintain a database of services, service instances and nodes.

Its responsibilities include gathering information about:

  • Nodes: each OpenOrch server registers itself as a node, which roughly correlates to a physical machine

This page is a high level overview of the Registry Svc. For more details, please see the Registry Svc API documentation.

Entities​

Definition​

A Definition or service definition consists of the following things:

  • An ID
  • A container image to run and some additional information like the internal port exposed etc.
  • A set of endpoint definitions (OpenAPI etc.)
  • The URL of different clients (JS, Go etc.)

A Definition is an abstract concept that can not be called. For a callable entity look at Instances. Definitions are basically things you can deploy as an instance with a deployment.

Container based definition​

id: test-a
image:
  name: hashicorp/http-echo
  port: 8080
hostPort: 8887

Notes​

HostPorts are a temporary requirement until support for dynamic port assignment lands.

Source code based definition​

id: test-b
repository:
  url: https://github.com/openorch/openorch.git
  containerFile: server/docker/Dockerfile
hostPort: 9998

Instance​

A Instance or a service instance is an actual running, callable instance of a Definition.

A Instance consists of the following things:

  • Address information that can be used to internally address the Instance.
  • A Deployment ID.

Deployment​

Definitions become instances through the Deployment entity of the Deploy Service.

Node​

A Node is a physical or virtual machine that runs a OpenOrch daemon. The daemon can then lauch service instances or other processes such as containers on these machines.

Maintaining a list of nodes is important so the daemon can efficiently distribute workload across the nodes.

How It Works​

The registry is needed when you want to call services not included in the OpenOrch daemon. You can think of the daemon as the standard library and services in the registry as third party libraries.

When you want to call a service, you can ask the registry to provide you with a list of instance addresses for a service by service slug. Then you can use any of those instance addresses to make a call.

Things like load balancing should be done on the client side at the moment, the damon does not provide a Proxy Svc yet.