Entrypoints and commands are working together in a Docker container, if you specify an entrypoint, your command will be passed as an argument to the entrypoint, and if that entrypoint does nothing with the arguments passed to it, then the behaviour you are observing it totally normal.
The chapter "Understand how CMD and ENTRYPOINT interact" of the documentation provides a nice table explaining in depth how they interact.
In order to run you tests from that image, you could override the entrypoint when running you container:
docker run --entrypoint "" cygnetops/react-test mvn test
Note:
- you will also have to install Maven, as it is not part of your base image
- as you pointed, you will also need the POM and files of the Java project in order to run the tests, so you need to copy those sources in the image
So, add, in your Dockerfile, the lines:
COPY . .
RUN apk add --no-cache maven
If you want both to work, on the other hand, you will have to write your own entrypoint and make something from the command passed as arguments.
Here is an example:
entrypoint.sh, should be located at the same level as your Dockerfile:
#!/usr/bin/env sh
exec "$@" # execute what is passed as argument
java -Djava.security.egd=file:/dev/./urandom -jar /app.jar
Then, for your Dockerfile
FROM eclipse-temurin:17-jdk-alpine
VOLUME /tmp
RUN apk add --no-cache maven
COPY . .
COPY /target/demoCI-CD-0.0.1-SNAPSHOT.jar app.jar
COPY entrypoint.sh /usr/local/bin/
ENTRYPOINT ["entrypoint.sh"]
EXPOSE 5000