onos-config-model

README

Config Model Support

This project provides a library and tools for managing YANG models in Go. It defines the primary interfaces for YANG-based ConfigModels, provides a Registry abstraction for managing models, and includes a PluginCompiler which supports compiling and loading models from YANG modules at runtime.

Agent

The config agent is a tool that supports compiling and managing config models for Kubernetes services. The agent is provided as a Docker image which can be built with make:

> make images

Because the agent compiles Go modules, the compiler images are very large and should not be extended for service images. Instead, the agent should be deployed either as an init container or a sidecar to compile and manage config models as part of a deployment.

When deployed as an init container, the config-model compile sub-command can be used to compile model plugins for the primary service:

> go run github.com/onosproject/onos-config-model/cmd/config-model compile \
    --name test \
    --version 1.0.0 \
    --module test@2020-11-18=/root/plugins/test/test@2020-11-18.yang \
    --build-path /root/build/test
    --output-path /root/plugins

The agent can also be run as a sidecar to compile and manage config models throughout the lifetime of a service. To run the agent:

> make serve

The agent implements a gRPC API exposing the config model registry to clients. The config-model registry sub-commands can be used to interact with the agent server:

To push a new model to the model registry, use the registry push sub-command:

> go run github.com/onosproject/onos-config-model/cmd/config-model registry push \
    --name foo \
    --version 1.0.0 \
    --module test@2020-11-18=plugins/test/test@2020-11-18.yang

The agent will compile the model and add it to the registry. You can list the contents of the registry with the list command or get information about a specific model with the get command:

> go run github.com/onosproject/onos-config-model/cmd/config-model registry list
{
  "name": "foo",
  "version": "1.0.0",
  "modules": [
    {
      "name": "test",
      "organization": "",
      "version": "2020-11-18",
      "data": "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"
    }
  ],
  "plugin": {
    "name": "foo",
    "version": "1.0.0",
    "file": "foo-1.0.0.so"
  }
}

The JSON output above is the config model definition used to track the model within the model registry. The model plugin can be loaded from within the agent container or any other container that shared the model volume with the config agent. To load a model, simply call the Load function:

import "github.com/onosproject/onos-config-model/pkg/model"

...

// Load the foo/1.0.0 model from a shared volume
fooModel, err := model.Load("models/foo-1.0.0.so")

The model object that's returned will be a generated implementation of the ConfigModel interface.