Docker bind-mount not working as expected within AWS EC2 Instance - docker

Question

I have created the following Dockerfile to run a spring-boot app: myapp within an EC2 instance.
# Use an official java runtime as a parent image
FROM openjdk:8-jre-alpine
# Add a user to run our application so that it doesn't need to run as root
RUN adduser -D -s /bin/sh myapp
# Set the current working directory to /home/myapp
WORKDIR /home/myapp
#copy the app to be deployed in the container
ADD target/myapp.jar myapp.jar
#create a file entrypoint-dos.sh and put the project entrypoint.sh content in it
ADD entrypoint.sh entrypoint-dos.sh
#Get rid of windows characters and put the result in a new entrypoint.sh in the container
RUN sed -e 's/\r$//' entrypoint-dos.sh > entrypoint.sh
#set the file as an executable and set myapp as the owner
RUN chmod 755 entrypoint.sh && chown myapp:myapp entrypoint.sh
#set the user to use when running the image to myapp
USER myapp
# Make port 9010 available to the world outside this container
EXPOSE 9010
ENTRYPOINT ["./entrypoint.sh"]
Because I need to access myapp's logs from the EC2 host machine, i want to bind-mount a folder into the logs folder sitting within "myapp" container here: /home/myapp/logs
This is the command that i use to run the image in the ec2 console:
docker run -p 8090:9010 --name myapp myapp:latest -v home/ec2-user/myapp:/home/myapp/logs
The container starts without any issues, but the mount is not achieved as noticed in the following docker inspect extract:
...
"Mounts": [],
...
I have tried the followings actions but ended up with the same result:
--mount type=bind instead of -v
use volumes instead of bind-mount
I have even tried the --privileged option
In the Dockerfile: I tried to use the USER root instead of myapp
I believe that, this has nothing to do with the ec2 machine but my container. Since running other containers with bind-mounts on the same host works like a charm.
I am pretty sure i am messing up with my Dockerfile.
But what am i doing wrong in that Dockerfile ?
or
What am i missing out ?
Here you have the entrypoint.sh if needed:
#!/bin/sh
echo "The app is starting ..."
exec java ${JAVA_OPTS} -Djava.security.egd=file:/dev/./urandom -jar -Dspring.profiles.active=${SPRING_ACTIVE_PROFILES} "${HOME}/myapp.jar" "$#"

Answer 1

I think the issue might be the order of the options on the command line. Docker expects the last two arguments to be the image id/name and (optionally) a command/args to run as pid 1.
https://docs.docker.com/engine/reference/run/
The basic docker run command takes this form:
$ docker run [OPTIONS] IMAGE[:TAG|#DIGEST] [COMMAND] [ARG...]
You have the mount options (-v in the example you provided) after the image name (myall:latest). I'm not sure but perhaps the -v ... is being interpreted as arguments to be passed to your entrypoint script (which are being ignored) and docker run isn't seeing as a mount option.
Also, the source of the mount here (home/ec2-user/myapp) doesn't start with a leading forward slash (/), which, I believe, will make it relative to where the docker run command is executed from. You should make sure the source path starts with a forward slash (i.e. /home/ec2-user/myapp) so that you're sure it will always mount the directory you expect. I.e. -v /home/ec2-user...
Have you tried this order:
docker run -p 8090:9010 --name myapp -v /home/ec2-user/myapp:/home/myapp/logs myapp:latest