gke-springboot

This is a Spring Boot project. It is created to demonstrate how to create a sample API service in spring boot, how to containerize it as a docker container and how to deploy it on Google Kubernetes engine (GKE)

This is a sample API that uses Customer entity to describe CRUD operations like createCustomer, updateCustomer & deleteCustomer. Cloud SQL is used as a backend to store the Customer entity data. Spring boot & Docker container used as a micro service container. JDBC Template from Spring framework is used to persist the data.

Sample Customer profile table created in Cloud MySQL

MySQL [customer_master]> describe profile;

Field	Type	Null	Key	Default	Extra
email	varchar(255)	NO	PRI	NULL
firstName	varchar(255)	YES		NULL
lastName	varchar(255)	YES		NULL
address	varchar(500)	YES		NULL
last_updated	timestamp	NO		CURRENT_TIMESTAMP	on update CURRENT_TIMESTAMP

Connecting to Cloud MySQL from Spring Boot

Inorder to connect to the Cloud MySQL from SpringBoot application please follow the steps listed below and these 3 steps are mandatory whether you are running the conainers in cloud or local.

1. Clone the code from Google cloud github using the URL "git clone https://github.com/spring-cloud/spring-cloud-gcp"
2. After cloning the repository go to the directory "spring-cloud-gcp"
3. Run mvnw install (If the machine where you are running this command if it has a low memory it is advised to run it with skipTests & skipJavaDoc options). This command essentially installs the GCP libraries in local maven repository.

Make sure the build & install is successful

For all dependencies please refer pom.xml under project root directory

4. MySQL username & password properties are added to the application properties file.
   spring.datasource.username=root
   spring.datasource.password=${CLOUD_SQL_DEV_DB_PASSWORD} # this is the environment variable

Java programs that made up API

1. CustomerController
   • This is the implementation of API end point and implements the CRUD operations like createCustomer, getCustomer, updateCustomer & deleteCustomer. And this class in turn calls the CustomerDAO to get the data from MySQL database. CustomerDAO object is auto wired into this class using auto wire annotation.
2. CustomerDAO
   • This is the DAO implementation class that creates, updates & deletes the customer details. And this uses the spring JDBCTemplate out of box utitlity to interact with MySQL database.

Containerizing the application and running on docker (Local machine or Google cloud shell)

To containerize the application please follow the steps. (Note: Please make sure the first 3 steps of section 'Connecting to Cloud MySQL from Spring Boot' are followed)

1. Clone this repository
2. A file with the name Dockerfile is created under project root directory
3. jib-maven-plugin is added to pom.xml (Please refer the file created under project root directory)
4. Run maven command "mvn compile jib:dockerBuild" to create the image
5. Run the following command on the command/terminal. Please pay attention to the way we are passing environment variables(i.e., CLOUD_SQL_DEV_DB_PASSWORD, GOOGLE_APPLICATION_CREDENTIALS. Note: this is only needed when you are running the docker container for testing before deploying it to GKE) to the docker container. And the option SPRING_PROFILES_ACTIVE is used to tell the application what environment profile it needs to look for.
   • docker run -p 8080:8080 -e "SPRING_PROFILES_ACTIVE=dev" -e CLOUD_SQL_DEV_DB_PASSWORD='welcome1' -v /Users/Raghu/gcp/:/var/gcp -e GOOGLE_APPLICATION_CREDENTIALS='/var/gcp/SpringMLProject-12a525884889.json' -t gcr.io/springmlproject/customer:0.0.1-SNAPSHOT
6. Once the application runs successfully please access the URL http://localhost:8080/customer/all

Deploying the application on Google Kubernetes Engine (GKE)

To deploy the application on GKE please follow the steps (Note: Please make sure the first 3 steps of section 'Connecting to Cloud MySQL from Spring Boot' are followed)

Creating & Running docker image

1. Clone this repository in Google cloud shell
2. Run the maven command to push docker image to google container registry.
   • mvn compile jib:build
3. Run the docker container and see it is working
   • docker run -p 8080:8080 -e "SPRING_PROFILES_ACTIVE=dev" -e CLOUD_SQL_DEV_DB_PASSWORD='welcome1' -t gcr.io/springmlproject/customer:0.0.1-SNAPSHOT
4. open the localhost window in cloud shell and append the URL with /customer/all. This should display all the data exists in profile table.

Deploying docker image on the GKE cluser

1. Run the deploy command
   • kubectl apply -f Deployment.yml
2. To view the deployment
   • kubectl get deployments
3. To see the application instances
   • kubectl get pods
4. To make the deployment visible to outside world
   • kubectl expose deployment dustomer --type=LoadBalancer
5. To get the public IP please run the command
   • kubectl get services
6. To access the application please use the url http://{public-ip}:8080/customer/all