Light Controller Tutorial

The light-controller is part of the light-portal, and it is responsible for managing live instances in a microservices deployment in real-time. For most users who cannot deploy the light-portal or just want to set up an environment for development, we have peeled the light-portal functionality and created a free open source edition. The published docker image is free to use with a docker-compose.yml in the light-controller repository for users who prefer Docker.

  • Petstore Registry to show users how to the light-controller for service interaction.

  • Service Discovery to show users how to leverage the light-controller for global registry and discovery.

  • Kubernetes Cluster to show users how to use the light-controller in a Kubernetes cluster for instance management and goblal discovery.

  • Local IDE to integrate light-scheduler, light-controller and petstore API

  • Local Docker to integrate light-scheduler, light-controller and petsotre API with multiple nodes docker-compose.

Local Controller Cluster with docker-compose

For production, the light controller should be deployed in cluster mode with at least three instances. As it depending on the light-scheduler, we also need to deploy three instances of light-scheduler. To complete the function, we will use the pet store service to register to the controller. Start Confluent cd ~/networknt/kafka-sidecar docker-compose up Start Scheduler cd ~/networknt/light-scheduler docker-compose up Start Controller cd ~/networknt/light-controller docker-compose up Start Petstore cd ~/networknt/light-example-4j/rest/petstore-maven-single mvn clean install -Prelease java -jar target/server. Read More »

Local Controller in IDE

In this step, we will start confluent platform, light-scheduler, light-controller and petstore in IDE to use local configuration and debug three applications together during the development. Confluent Platform cd ~/networknt/kafka-sidecar docker-compose up Light-Scheduler Start the light-scheduler with the config/local config folder. Light-Controller Start the light-controller with the config/local config foler. Petstore Start petstore from light-example-4j/rest/petstore-maven-single in IDE with default configuration. Test From the browser, enter the URL. https://localhost:8438 Video Read More »

Kubenetes Cluster

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Service Discovery

The light-controller is a global registry that manages all the live instances of microservices in the system. Also, the health check ensures the registry’s information is up to date all the time, which is very valuable for service discovery. In a microservices application, before the consumer invokes a service, it can look up in the registry for all the available nodes and pick up one to establish a connection. After that, the same connection can be cached for a while or for a number of requests configured in the client. Read More »

Petstore Registry

In this tutorial, we will start the light-controller with a docker-compose and start the petstore-regsitry from the light-example-4j to register it to the controller. Once we can see the instance on the controller dashboard, we can check the health, server info, and manipulate the petstore handler’s logger level. Controller To allow other services to register to the controller, we need to start the controller first. cd ~/networknt/light-docker docker-compose -f docker-compose-controler.yml up Petstore Once the controller is up and running, we can start the petstore service. Read More »