This is a small example that uses Java and Springboot to provision a simple REST api. It uses the Maven build system and the Spotify Docker plugin.
The api will listen for requests on port 8080. Note that this is the port number that the build pipelines will use when defining the ECS tasks and load balancer rules. Changing the api to use a different port will result in incorrect deployment of the resulting container.
It will respond to the following requests:
- /
- /greeting
- /greeting?name=Albert
- /systeminfo
- /systeminfo?detail=all
- /systeminfo?detail=properties
- /systeminfo?detail=environment
- /messages
- /messages/add?name=hello&message=Hello
Note that the systeminfo requests can return detailed Java system property and environment variable information. Care should to taken to ensure this is only deployed for development purposes.
Because the example api uses Java it needs to be compiled, a jar file file created and, ultimately, a Docker image produced. To do this a Java JDK, and Apache Maven need to be installed and configured. The Dockerfile specifies OpenJDK version 8.
To build and execute locally execute:
mvn clean package
mvn spring-boot:run
This will start the api on port 8080. The run on a different port, for example 18080 use:
mvn -Dserver.port=18080 spring-boot:run
You may wish to use a different port when an application and api are being run locally. See the example application repository, CMpExampleApp1.
Now the api is running locally it is possible make requests to it, for example using curl:
curl http://localhost:8080/greeting
will return a JSON object like: {"id":1,"content":"Hello, World!"}.
The corresponding example build pipeline project is in the CMpDevEnvironment repository as /terraform/build/api1. The pipeline currently needs to be stored within the CMpDevEnvironment repository because it requires access to various Terraform modules.
The project includes a simple Docker file, this is used by the build pipeline to generate the container image. It is a standard file for a Java Springboot based project. It must expose port 8080. The name of the container image is defined in the Maven pom.xml file. For the example it is ccs/api1.
To build the Docker image locally execute:
mvn install dockerfile:build
Note that this is using the Spotify Maven plugin and Docker must also be installed locally. Do not try and build the image using docker image build.
The resulting image can be executed using:
docker run -p 8080:8080 ccs/api