Microservice with Spring Boot in Google Kubernetes Engine

Building an application using the following technology stack.

Spring Boot / Kotlin / k8s (Google Kubernetes Engine) / CircleCI / RDB (Cloud SQL) / Cloud Endpoints / Firebase / gRPC

Architecture

Build locally

There are two ways to build development environment locally.

1. Use kubenetes (Recommend)
2. Not use kubenetes

Use Kubenetes

Comming soon.

Not use Kubenetes

Start worker service

$ cd worker-service
$ ./gradlew bootRun -Dspring.profiles.active=h2

Start gRPC Web Proxy

$ docker run -p 8080:8080 --rm -it jfyne/docker-grpcwebproxy /grpcwebproxy --backend_addr=host.docker.internal:6565 --run_tls_server=false

Start web client

$ cd web-client
$ ionic serve

Now, you can access http://localhost:8100 .

Build on Google Cloud Platform with CircleCI

Google Kubernetes Engine

$ gcloud container clusters create demo-cluster --num-nodes=1 --machine-type=n1-standard-2 --service-account=gke-sample-app@possible-enoch.iam.gserviceaccount.com 
$ gcloud container clusters get-credentials demo-cluster

Cloud SQL

$ gcloud sql users create proxyuser cloudsqlproxy~% --instance=[INSTANCE_NAME] --password=[PASSWORD]
$ kubectl create secret generic cloudsql-instance-credentials \
    --from-file=$[CREDENTIAL_FILE]
$ kubectl create secret generic cloudsql-db-credentials \
     --from-literal=username=proxyuser --from-literal=password=[PASSWORD]

Appendix

IDE

IntelliJ IDEA 2017.3.5 (Ultimate Edition)
Build #IU-173.4674.33, built on March 6, 2018
Licensed to Takahiro Suzuki
Subscription is active until April 15, 2018
JRE: 1.8.0_152-release-1024-b15 x86_64
JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
Mac OS X 10.13.3

Spring Boot / Kotlin

Use example project
https://github.com/JetBrains/kotlin-examples/tree/master/tutorials/spring-boot-restful

Document
https://kotlinlang.org/docs/tutorials/spring-boot-restful.html

k8s (Google Kubernetes Engine)

Run a Kotlin Spring Boot application on Google Kubernetes Engine
https://cloud.google.com/community/tutorials/kotlin-springboot-container-engine

CircleCI

Creating and Managing Service Account Keys https://cloud.google.com/iam/docs/creating-managing-service-account-keys?hl=ja

Add the following roles to service account TODO: minimize roles

• Cloud Container Builder
• Kubernetes Engine Admin
• Storage Admin
• Viewer

Deploying to Google Kubernetes Engine
https://circleci.com/docs/2.0/google-container-engine/

Add the following environment variables in CircleCI

• GCLOUD_SERVICE_KEY
• GOOGLE_CLUSTER_NAME
• GOOGLE_COMPUTE_ZONE
• GOOGLE_PROJECT_ID

Auth0

Spring Security Java API Authorization
https://auth0.com/docs/quickstart/backend/java-spring-security/01-authorization

Exposed

Sample project
https://github.com/sdeleuze/geospatial-messenger

Blog
https://spring.io/blog/2016/03/20/a-geospatial-messenger-with-kotlin-spring-boot-and-postgresql

jOOQ

You can exclude the generated code from version control. But this project is including that.

generate source code

$ ./gradlew generateWorkerJooqSchemaSource

etiennestuder/gradle-jooq-plugin https://github.com/etiennestuder/gradle-jooq-plugin

Generate Kotlin data classes #6345 jOOQ/jOOQ#6345

gRPC

LogNet/grpc-spring-boot-starter https://github.com/LogNet/grpc-spring-boot-starter

Cloud SQL

Connect Kubernetes Engine https://cloud.google.com/sql/docs/mysql/connect-kubernetes-engine

Appendix

• https://github.com/keitaro1020/k8s-example
• https://kotlinlang.org/docs/tutorials/spring-boot-restful.html
• https://cloudplatform-jp.googleblog.com/2018/02/announcing-Spring-Cloud-GCP-integrating-your-favorite-Java-framework-with-Google-Cloud.html