RESTful Web Service Implementation with Docker

This project is part of assignment at Pace University.

The project uses Maven build and is implemented using Spring Boot.

The web service contains four GET routes:

• One that displays a collection of records (List all tvshows)
• One that displays a single record that corresponds to an ID (List a particular tvshow)
• One that displays a collection of records for a given entity (List of cast for individual tvshow)
• One that displays a single record from a collection of a given entity (List a particular actor from the cast for individual tvshow)

Source Data

I have used a static [JSON] (https://github.com/jalpaashara/DockerSpringWebservice/blob/master/src/main/resources/data.json) as source for data.

Get Requests available

List all tvshows: localhost:8080/shows
List a particular tvshow: localhost:8080localhost:8080/shows/showId
List of cast for individual tvshow: localhost:8080/shows/id/cast
List a particular cast for individual tvshow: localhost:8080/shows/showId/cast/castId

Follow the below steps to create a local environment and run this Spring Boot Application

Step 1:

Download and unzip the source repository or clone it using Git:

git clone https://github.com/jalpaashara/DockerSpringWebservice.git

Step 2:

Go to terminal or command prompt and change the directory to where you have cloned or downloaded the project. Type in the following:

./mvnw package

This command is used to execute all Maven phases until the package phase. It does the job of compiling, verifying and building the project. It builds the jar file and places it in the target directory under the root project folder.

Step 3:

Containerize the project: Docker has a simple "Dockerfile" file format that it uses to specify the layers of an image. Dockerfile is included in this project and below is how I have created the Dockerfile:
FROM openjdk:8-jdk-alpine
VOLUME /tmp
ARG DEPENDENCY=target/dependency
COPY ${DEPENDENCY}/BOOT-INF/lib /app/lib
COPY ${DEPENDENCY}/META-INF /app/META-INF
COPY ${DEPENDENCY}/BOOT-INF/classes /app
ENTRYPOINT ["java","-cp","app:app/lib/*","com.info.shows.SpringShowsCastApplication"]
EXPOSE 8080

This Dockerfile has a DEPENDENCY parameter pointing to a directory. So from the terminal or command prompt type in the following:

mkdir -p target/dependency && (cd target/dependency; jar -xf ../*.jar)

This command will generate the following folders in the target/dependency folder BOOT-INF/classes - with the application classes BOOT-INF/lib - with the dependency jars META-INF

Step 4:

Now we have all the setup we need to build the docker image. To build the image you can use the Docker command line.

docker build -t springproj/DockerSpringWebservice .

-t -- tags the imagename "DockerSpringWebservice", you can optionally f=give a tag name after the imagename and a : (DockerSpringWebservice:v1.0).
If you dont provide a tagname, docker by defuault assigns latest to the tagname.'
Tagnames are useful when you have to version your build images.
You can check the image built by typing the following on your terminal/cmd:

docker images

Step 5:

Now you can run the docker image that is built using the following docker run command:

docker run -p 8080:8080 DockerSpringWebservice

-p - publishes a container’s port(s) to the host
Now go to the browser and type localhost:8080 and it will show you a JSON with the list of tvshows and their cast.
To see the details of individual tvshows: localhost:8080/shows/143 or localhost:8080/shows/329 or localhost:8080/shows/72
To see the details of cast for individual tvshows: localhost:8080/shows/143/cast or localhost:8080/shows/329/cast or localhost:8080/shows/4123009/cast
To see the details of a particular cast for individual tvshows: localhost:8080/shows/143/cast/20942 or localhost:8080/shows/143/cast/27669 or localhost:8080/shows/329/cast/67991 or localhost:8080/shows/72/cast/5517 or localhost:8080/shows/72/cast/5368

Step 6 (Optional)

Until now we have used docker locally to build and run in our local environment.
Now we can push the docker image to docker hub and run it from anywhere.
The command to push the docker image is:

docker push springproj/DockerSpringWebservice

Before you do this make sure you are logged in to Docker. to login to docker use the command below:

docker login

And it will authenticate you and login to your docker hub repositories.
Once your image is on the docker hub, you can run it using the run command in Step 5 from anywhere.

Other useful docker commands

docker ps

Lists all the docker container running

docker stop my_container_id

Stops the running container with id 'my_container_id'. You can get the containerId from docker ps.