ballerina init  -i

├── Ballerina.toml
├── Dockerfile
├── README.md
├── docker-compose.yml
├── hello_service.bal
├── target
│ └── hello_service.balx
└── tests
    └── hello_service_test.bal

// A system package containing protocol access constructs
// Package objects referenced with 'http:' in code
import ballerina/http;
import ballerina/io;

// A service endpoint represents a listener
endpoint http:Listener listener {
port:9090
};

// A service is a network-accessible API
// Advertised on '/hello', port comes from listener endpoint
service<http:Service> hello bind listener {

// A resource is an invokable API method
// Accessible at '/hello/sayHello
// 'caller' is the client invoking this resource
sayHello (endpoint caller, http:Request request) {

// Create object to carry data back to caller
http:Response response = new;

// Objects and structs can have function calls
response.setTextPayload("Hello Ballerina!\n");

// Send a response back to caller
// Errors are ignored with '_'
// -> indicates a synchronous network-bound call
_ = caller -> respond(response);
}
}

# build stage
# FROM ballerina/ballerina-platform AS build-env
# ADD . /home/ballerina/
# RUN ballerina build hello_service.bal
# RUN ls .
FROM ballerina/ballerina
EXPOSE 9090
COPY hello_service.bal /home/ballerina
RUN ls .
ENTRYPOINT [ "ballerina","run","hello_service.bal" ]

version: "3"
services:
http:
build: .
image: myhttp
ports:
- "9099:9090"

docker-compose build
docker-compose up -d