Unable to access jarfile - Docker on Elastic Beanstalk - amazon-web-services

Question

I am trying to deploy a Docker image of a Spring Boot application to AWS Elastic Beanstalk and I'm encountering this error in /var/log/eb-activity.log:
Docker container quit unexpectedly after launch: Docker container quit unexpectedly on Wed Jun 22 11:56:25 UTC 2016:
Error: Unable to access jarfile /home/packedit/app/packed-it.jar. Check snapshot logs for details. (Executor::NonZeroExitStatus)
This is a single container on Elastic Beanstalk with the following Dockerrun.aws.json:
{
"AWSEBDockerrunVersion": "1",
"Image": {
"Name": "packedit/packedit-api",
"Update": "true"
},
"Ports": [
{
"ContainerPort": "8080"
}
],
"Volumes": [
{
"HostDirectory": "/var/app/packedit",
"ContainerDirectory": "/home/packedit/app"
}
],
"Logging": "/home/packedit/app/logs"
}
This is the Dockerfile:
FROM java:8
MAINTAINER my#email.com
VOLUME /tmp
EXPOSE 8080
ENV USER_NAME packedit
ENV APP_HOME /home/$USER_NAME/app
ENV APP_FILENAME packed-it.jar
RUN useradd -ms /bin/bash $USER_NAME
RUN mkdir -p $APP_HOME/data
ADD $APP_FILENAME $APP_HOME/$APP_FILENAME
RUN chown -R $USER_NAME $APP_HOME/
USER $USER_NAME
WORKDIR $APP_HOME
RUN bash -c 'touch $APP_FILENAME'
# Can't use $APP_FILENAME here because ENTRYPOINT does not do ENV replacement
# See: http://stackoverflow.com/a/28854410/336752
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","packed-it.jar"]
I have successfully deployed the Docker image to an EC2 instance using ECS but I have not succeeded with Elastic Beanstalk. My guess is that I am doing something wrong with the volumes but I am struggling to understand the documentation. I originally started with a multicontainer configuration but have simplified to try and isolate my issue.
Thanks for any advice.

Answer 1

You need to remove the line
"ContainerDirectory": "/home/packedit/app"
from your Dockerrun.aws.json.
It seems like the confusion is with how docker volumes work. The volumes are allocated at runtime and persist on consecutive runs on the same machine.
Here is what is happening. The docker image is built with jar in /home/packedit/app but since you have defined a volume in the same location, an empty volume is created when it is run and mounted in that location. Hence, the same directory of the image is ignored.
Here is how you can reproduce the issue locally:
docker build .
docker run -v /home/packedit/app IMAGEID_FROM_OUTPUT_OF_PREVIOUS_COMMAND