import ballerina/http;
import ballerina/log;

// Note that the code below is completely focused on the business logic and it does not specify anything related to operations.
listener http:Listener helloEP = new(9090);

service http:Service /helloWorld on helloEP {
    resource function get sayHello(http:Caller caller) {
        var responseResult = caller->respond("Hello, World from service helloWorld ! \n");
        if (responseResult is error) {
            log:printError("error responding back to client.", err = responseResult);
        }
    }
}

Code to Cloud Deployment

Ballerina supports generating Docker and Kubernetes artifacts from code without any additional configuration. This simplifies the experience of developing and deploying Ballerina code in the cloud. Code to cloud builds the containers and required artifacts by deriving the required values from the code. If you want to override the default values taken by the compiler, you can use a Cloud.toml file.

For more information, see Code to Cloud Deployment.

 
import ballerina/http;
import ballerina/log;

listener http:Listener helloEP = new(9090);

Note that the code below is completely focused on the business logic and it does not specify anything related to operations.

 
service http:Service /helloWorld on helloEP {
    resource function get sayHello(http:Caller caller) {
        var responseResult = caller->respond("Hello, World from service helloWorld ! \n");
        if (responseResult is error) {
            log:printError("error responding back to client.", err = responseResult);
        }
    }
}

# Before you build the package, we are going to override some of the default values taken by the compiler,
In order to do this you need to create a filed named `Cloud.toml` in package directory and paste the following content into it.
All the supported key value properties can be found in the Code to cloud deployment guide.

[container.image]
repository="wso2inc"
name="hello"
tag="v0.1.0"

Additionally, if you are using minikube, you could execute the following command to reuse the Docker daemon from minikube.
$ eval $(minikube docker-env)

# Now let's build the ballerina package.

# Note that the `bal build` command should be executed on the package. Code to cloud generates only one container per package.
$ bal build

Compiling source
        wso2/hello:0.1.0

Creating balas
        target/bala/hello-2020r2-any-0.1.0.bala

Running Tests

        wso2/hello:0.1.0
        No tests found

Generating executables
        target/bin/hello.jar

Generating artifacts...

        @kubernetes:Service                      - complete 1/1
        @kubernetes:Deployment                   - complete 1/1
        @kubernetes:HPA                          - complete 1/1
        @kubernetes:Docker                       - complete 2/2

        Execute the below command to deploy the Kubernetes artifacts:
        kubectl apply -f /home/wso2/project/target/kubernetes/hello-0.1.0

        Execute the below command to access service via NodePort:
        kubectl expose deployment wso2-hello-0--deployment --type=NodePort --name=wso2-hello-0--svc-local

# Let’s try executing the Docker image separately first.

# Verify if the Docker image is generated.
$ docker images

REPOSITORY                    TAG                 IMAGE ID            CREATED             SIZE
wso2inc/hello                       v0.1.0              60d95f0928b2        About a minute ago   228MB

# Run the generated Docker image.
$ docker run -d -p 9090:9090 wso2inc/hello:v0.1.0
c04194eb0b4d0d78cbc8ca55e0527d381d8ab4a1a68f8ea5dd3770a0845d5fbb

# Access the service.
$ curl http://localhost:9090/helloWorld/sayHello
Hello, World from service helloWorld !

# Lets try executing Kubernetes service now.
$ kubectl apply -f /home/wso2/project/target/kubernetes/hello-0.1.0
service/helloep-svc created
deployment.apps/wso2-hello-0--deployment created
horizontalpodautoscaler.autoscaling/wso2-hello-0--hpa created

# Verify the kubernetes pods.
$ kubectl get pods
NAME                                          READY   STATUS    RESTARTS   AGE
wso2-hello-0--deployment-7d4d56457b-7jlzx   1/1     Running   0          57s

# Expose via Nodeport to test in the developer environment.
$ kubectl expose deployment wso2-hello-0--deployment --type=NodePort --name=wso2-hello-0--svc-local
service/wso2-hello-0--svc-local exposed

# Get the IP and port of the Kubernetes service.
$ kubectl get svc
NAME                        TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)          AGE
wso2-hello-0--svc-local   NodePort    10.111.61.112    <none>        9090:32437/TCP   4m17s

# If you are using Minikube, IP address should be changed according to the output of the `minikube ip` command.
$ minikube ip
192.168.49.2

# Access the deployed service via CURL.
$ curl http://192.168.49.2:32437/helloWorld/sayHello
Hello, World from service helloWorld !