Spring Boot in Docker - docker

Question

I am learning how to use Docker with a Spring Boot app. I have run into a small snag and I hope someone can see the issue. My application relies heavily on #Value that are set in environment specific properties files. In my /src/main/resources I have three properties files
application.properties
application-local.properties
application-prod.properties
I normally start my app with:
java -jar -Dspring.profiles.active=local build/libs/finance-0.0.1-SNAPSHOT.jar
and that reads the "application-local.properties" and runs properly. However, I am using this src/main/docker/DockerFile:
FROM frolvlad/alpine-oraclejdk8:slim
VOLUME /tmp
ADD finance-0.0.1-SNAPSHOT.jar finance.jar
RUN sh -c 'touch /finance.jar'
EXPOSE 8081
ENV JAVA_OPTS=""
ENTRYPOINT [ "sh", "-c", "java $JAVA_OPTS -Djava.security.egd=file:/dev/./urandom -jar /finance.jar" ]
And then I start it as:
docker run -p 8081:80 username/reponame/finance
-Dspring.profiles.active=local
I get errors that my #Values are not found:
Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'spring.datasource.driverClassName' in value "${spring.datasource.driverClassName}"
However, that value does exist in both *.local & *.prop properties files.
spring.datasource.driverClassName=org.postgresql.Driver
Do I need to do anything special for that to be picked up?
UPDATE:
Based upon feedback from M. Deinum I changing my startup to be:
docker run -p 8081:80 username/reponame/finance
-eSPRING_PROFILES_ACTIVE=local
but that didn't work UNTIL I realized order matter, so now running:
docker run -e"SPRING_PROFILES_ACTIVE=test" -p 8081:80 username/reponame/finance
works just fine.

Answer 1

You can use docker run Using Spring Profiles. Running your freshly minted Docker image with Spring profiles is as easy as passing an environment variable to the Docker run command
$ docker run -e "SPRING_PROFILES_ACTIVE=prod" -p 8080:8080 -t springio/gs-spring-boot-docker
You can also debug the application in a Docker container. To debug the application JPDA Transport can can be used. So we’ll treat the container like a remote server. To enable this feature pass a java agent settings in JAVA_OPTS variable and map agent’s port to localhost during a container run.
$ docker run -e "JAVA_OPTS=-agentlib:jdwp=transport=dt_socket,address=5005,server=y,suspend=n" -p 8080:8080 -p 5005:5005 -t springio/gs-spring-boot-docker
Resource Link:
Spring Boot with Docker
Using spring profile with docker for nightly and dev build:
Simply set the environment varialbe SPRING_PROFILES_ACTIVE when starting the container. This will switch the active of the Spring Application.
The following two lines will start the latest Planets dev build on port 8081 and the nightly build on port 8080.
docker run -d -p 8080:8080 -e \"SPRING_PROFILES_ACTIVE=nightly\" --name nightly-planets-server planets/server:nightly
docker run -d -p 8081:8080 -e \"SPRING_PROFILES_ACTIVE=dev\" --name dev-planets-server planets/server:latest
This can be done automatically from a CI system. The dev server contains the latest build and nightly will be deployed once a day...

Answer 2

There are 3 different ways to do this, as explained here
Passing Spring Profile in Dockerfile
Passing Spring Profile in Docker
run command
Passing Spring Profile in DockerCompose
Below an example for a spring boot project dockerfile
<pre>FROM java:8
ADD target/my-api.jar rest-api.jar
RUN bash -c 'touch /pegasus.jar'
ENTRYPOINT ["java", "-Djava.security.egd=file:/dev/./urandom","-Dspring.profiles.active=dev","-jar","/rest-api.jar"]
</pre>
You can use the docker run command
docker run -d -p 8080:8080 -e "SPRING_PROFILES_ACTIVE=dev" --name rest-api dockerImage:latest
If you intend to use the docker compose you can use something like this
version: "3"
services:
rest-api:
image: rest-api:0.0.1
ports:
- "8080:8080"
environment:
- "SPRING_PROFILES_ACTIVE=dev"
More description and examples can be found here