Spring Boot deployed in Google Kubernetes Engine(GKE) using Hashicorp Consul for application properties.

Motivation

• Consul is a better tool for managing application properties rather using ConfigMaps.

Prerequisites

• Maven
• Docker
• Spring Boot
• Kubernetes(GKE)

Steps to configure Consul on GKE

• Create a GKE 3 node cluster using Console or CLI
• Add the HashiCorp Helm Chart repository using Cloud Shell

helm repo add hashicorp https://helm.releases.hashicorp.com

• Create the configuration to override Helm Chart's default

# helm-consul-values.yaml
global:
  datacenter: myconsulcluster

ui:
  service:
    type: 'LoadBalancer'

• Using Helm 3x install Consul in GKE

helm install -f helm-consul-values.yaml hashicorp hashicorp/consul

• Once the deployment is completed get the External IP using kubectl and access the Consul UI
• Navigate Consul Key/Value
• Create a Key/Value used by the application, the parent folder should be Config and then the

  http://34.121.213.232/ui/myconsulcluster/kv/config/supermanservice/message.greetings/edit

• Create a Spring Boot app using the above project. Before deploying check the internal Consul Service IP and replace it bootstrap.yaml
• By default, Spring Boot will try to connect to the Consul agent at localhost:8500. To use other settings, we need to update the application.yml/bootstrap.yaml file:

spring:
  cloud:
    consul:
      host: <GKE Extenal/Internal IP>
      port: 80

• Using maven build your app. We are using spotify to generate the Docker image. You can also use Jib Maven plugin.

mvn clean install -D maven.test.skip=true 

• Once the Docker container is built, push it your own repository. The tag name is generated from the POM file

docker push subhankarde/supermanservice:<tag name>

• Update the deployment.yaml with image name and Consul IP.
• Deploy the app in the cluster

kubectl apply -f deployment.yaml

• Tear down

gcloud container clusters resize <cluster-name> --num-nodes=0 --zone us-central1-c