This repository contains sample inventory microservices to demonstrate how to use Spring, Kubernetes and Cassandra together a single stack.
Contributors:
Modules:
microservice-spring-boot: Service for Products- Persistence Layer : uses Cassandra Java driver's
CqlSessiondirectly for queries to products table - Exposition Layer : uses
spring-web@Controller
- Persistence Layer : uses Cassandra Java driver's
microservice-spring-data: Service for Orders- Persistence Layer : uses Spring Data Cassandra for data access to orders table
- Exposition Layer : uses Spring Data REST for API generation
gateway-service: Spring Cloud Gateway to route to the microservices
1. Objectives
Show a working set of microservices illustrating how to build Spring microservices with Kubernetes and Cassandra. This repo leverages Spring modules:
spring-dataspring-bootspring-data-restspring-webspring-cloud-kubernetesspring-cloud-gateway
2. How this Works
The primary mode of deployment is on a local Kubernetes cluster, though each service can be run standalone or in Docker.
The purpose is to show the many utilities of Spring in Kubernetes with Cassandra as the backing storage tier.
The business domain is an inventory / ecommerce application.
3. Setup and Running
3.a - Prerequisites
The prerequisites required for this application to run
- Docker
- Kubernetes
- JDK 11+
- Maven
3.b - Setup
Clone the current repository
git clone https://github.com/DataStax-Examples/spring-k8s-cassandra-microservices.git
Start minikube
# use docker as the virtualization driver minikube start --driver=docker --extra-config=apiserver.authorization-mode=RBAC,Node # tell minikube to use local docker registry eval `minikube docker-env`
Build the services
# from the spring-k8s-cassandra-microservices directory mvn package
Build the docker images
cd microservice-spring-boot; docker build -t <your-docker-username>/spring-boot-service:1.0.0-SNAPSHOT . cd microservice-spring-data; docker build -t <your-docker-username>/spring-data-service:1.0.0-SNAPSHOT . cd gateway-service; docker build -t <your-docker-username>/gateway-service:1.0.0-SNAPSHOT .
Alter deployment.yml files with your docker username
# replace image name in deploy/spring-boot/spring-boot-deployment.yml # replace image name in deploy/spring-data/spring-data-deployment.yml # replace image name in deploy/gateway/gateway-deployment.yml
Create namespaces
kubectl create ns cass-operator kubectl create ns spring-boot-service kubectl create ns spring-data-service kubectl create ns gateway-service
3.c - Setup DataStax Astra or Cassandra Kubernetes Operator
DataStax Astra
Create a free tier database in DataStax Astra with keyspace name betterbotz
Download the secure connect bundle from the Astra UI (docs)
Create secrets for the Astra username/password and secure connect bundle
DB_USER=<astra-db-user> DB_PASSWORD=<astra-db-password> SECURE_CONNECT_BUNDLE_PATH=<path-to-secure-connect-bundle>
kubectl -n spring-boot-service create secret generic db-secret --from-literal=username=$DB_USER --from-literal=password=$DB_PASSWORD kubectl -n spring-boot-service create secret generic astracreds --from-file=secure-connect-bundle=$SECURE_CONNECT_BUNDLE_PATH
kubectl -n spring-data-service create secret generic db-secret --from-literal=username=$DB_USER --from-literal=password=$DB_PASSWORD kubectl -n spring-data-service create secret generic astracreds --from-file=secure-connect-bundle=$SECURE_CONNECT_BUNDLE_PATH
Change Spring Boot ConfigMap to use secure connect bundle
apiVersion: v1
kind: ConfigMap
metadata:
name: spring-boot-service
data:
application.yml: |-
astra.secure-connect-bundle: /app/astra/creds
Change Spring Data ConfigMap to use secure connect bundle
apiVersion: v1
kind: ConfigMap
metadata:
name: spring-data-service
data:
application.yml: |-
astra.secure-connect-bundle: /app/astra/creds
Uncomment the following lines in Spring Boot Deployment.yml and Spring Data Deployment.yml
volumes:
- name: astravol
secret:
secretName: astracreds
items:
- key: secure-connect-bundle
path: creds
...
volumeMounts:
- name: astravol
mountPath: "/app/astra"
readOnly: true
You're ready to go!
Cassandra Kubernetes Operator
Start the Cassandra operator
# create the storage class for the database kubectl -n cass-operator apply -f deploy/storage-class.yml # apply the operator manifest kubectl -n cass-operator apply -f https://raw.githubusercontent.com/DataStax-Academy/kubernetes-workshop-online/master/1-cassandra/11-install-cass-operator-v1.1.yaml # start a single C* 4.0 node kubectl -n cass-operator apply -f deploy/cassandra-4.0.0-1node.yml
Create the Kubernetes Secrets for database username and password
# get the username and password from the secret DB_USER=$(kubectl -n cass-operator get secret cluster1-superuser -o yaml | grep username | cut -d " " -f 4 | base64 -d) DB_PASSWORD=$(kubectl -n cass-operator get secret cluster1-superuser -o yaml | grep password | cut -d " " -f 4 | base64 -d) # create k8s secrets for the services (skip cmd for Spring Boot service if using Astra) kubectl -n spring-boot-service create secret generic db-secret --from-literal=username=$DB_USER --from-literal=password=$DB_PASSWORD kubectl -n spring-data-service create secret generic db-secret --from-literal=username=$DB_USER --from-literal=password=$DB_PASSWORD
Running
Start the services
# from the spring-k8s-cassandra-microservices directory kubectl -n spring-boot-service apply -f deploy/spring-boot kubectl -n spring-data-service apply -f deploy/spring-data kubectl -n gateway-service apply -f deploy/gateway
Expose the Gateway endpoint
# get the gateway-service pod GATEWAY_POD=$(kubectl -n gateway-service get pods | tail -n 1 | cut -f 1 -d ' ') # forward the port kubectl -n gateway-service port-forward $GATEWAY_POD 8080:8080
Optionally expose the Spring Boot service endpoints (useful for testing)
# get the spring-boot-service pod BOOT_SERVICE_POD=$(kubectl -n spring-boot-service get pods | tail -n 1 | cut -f 1 -d ' ') # forward the port kubectl -n spring-boot-service port-forward $BOOT_SERVICE_POD 8083:8083
Optionally expose the Spring Data service endpoints (useful for testing)
# get the spring-data-service pod DATA_SERVICE_POD=$(kubectl -n spring-data-service get pods | tail -n 1 | cut -f 1 -d ' ') # forward the port kubectl -n spring-data-service port-forward $DATA_SERVICE_POD 8081:8081
Gateway Service endpoints
The Spring Cloud Gateway is running on port 8080 and forwards requests
to the Spring Boot and Spring Data endpoints below. To test that this is
working, you can replace the URLs below with localhost:8080 with the same
curl commands.
Spring Boot service endpoints
Explore the endpoints with Swagger (only works if endpoints exposed above): http://localhost:8083/swagger-ui.html
Add products
curl -X POST -H "Content-Type: application/json" -d '{"name": "mobile", "id":"123e4567-e89b-12d3-a456-556642440000", "description":"iPhone", "price":"500.00"}' http://localhost:8083/api/products/add
curl -X POST -H "Content-Type: application/json" -d '{"name": "mobile", "id":"123e4567-e89b-12d3-a456-556642440001", "description":"Android", "price":"600.00"}' http://localhost:8083/api/products/add
Get products with name = mobile
curl http://localhost:8083/api/products/search/mobile
Get products with name = mobile and id = 123e4567-e89b-12d3-a456-556642440001
curl http://localhost:8083/api/products/search/mobile/123e4567-e89b-12d3-a456-556642440001
Delete product with name = mobile and id = 123e4567-e89b-12d3-a456-556642440001
curl -X DELETE http://localhost:8083/api/products/delete/mobile/123e4567-e89b-12d3-a456-556642440001
Spring Data service endpoints
Add orders
curl -H "Content-Type: application/json" -d '{"key": {"orderId":"123e4567-e89b-12d3-a456-556642440000", "productId":"123e4567-e89b-12d3-a456-556642440000"}, "productName":"iPhone", "productPrice":"500.00", "productQuantity":1, "addedToOrderTimestamp": "2020-04-12T11:21:59.001+0000"}' http://localhost:8081/api/orders/add
curl -H "Content-Type: application/json" -d '{"key": {"orderId":"123e4567-e89b-12d3-a456-556642440000", "productId":"123e4567-e89b-12d3-a456-556642440001"}, "productName":"Android", "productPrice":"600.00", "productQuantity":1, "addedToOrderTimestamp": "2020-04-12T11:22:59.001+0000"}' http://localhost:8081/api/orders/add
Get orders with order_id = 123e4567-e89b-12d3-a456-556642440000
curl http://localhost:8081/api/orders/search/order-by-id?orderId=123e4567-e89b-12d3-a456-556642440000
Get order with order_id = 123e4567-e89b-12d3-a456-556642440000 and product_id = 123e4567-e89b-12d3-a456-556642440000
curl "http://localhost:8081/api/orders/search/order-by-product-id?orderId=123e4567-e89b-12d3-a456-556642440000&productId=123e4567-e89b-12d3-a456-556642440000"
Get only the product name and price of order_id = 123e4567-e89b-12d3-a456-556642440000
curl http://localhost:8081/api/orders/search/name-and-price-only?orderId=123e4567-e89b-12d3-a456-556642440000
Shows how to use a projection with Spring Data REST
curl "http://localhost:8081/api/orders/search/name-and-price-only?orderId=123e4567-e89b-12d3-a456-556642440000&projection=product-name-and-price"
Delete order with order_id = 123e4567-e89b-12d3-a456-556642440000 and product_id = 123e4567-e89b-12d3-a456-556642440000
curl -X DELETE "http://localhost:8081/api/orders/delete/product-from-order?orderId=123e4567-e89b-12d3-a456-556642440000&productId=123e4567-e89b-12d3-a456-556642440000"
Delete order with order_id = 123e4567-e89b-12d3-a456-556642440000
curl -X DELETE "http://localhost:8081/api/orders/delete/order?orderId=123e4567-e89b-12d3-a456-556642440000"
