Can not use jar inside docker

[lanliu99]

A helloworld java program can run with openjdk in unpackaged dir, but when package classes into jar, this doesn't work, here is detail:
#1. This Docker works with unpackeged dir used in Dockerfile:
Dockerfile
FROM openjdk
RUN mkdir /home/mylib
COPY ./classes /home/mylib
WORKDIR /home/mylib
RUN chmod -R 755 /home/mylib && ls -l /home/mylib
CMD ["java", "com.mycompany.app.App"]

docker build:
Sending build context to Docker daemon 20.48 kB
Step 1 : FROM openjdk
---> 7c57090325cc
Step 2 : RUN mkdir /home/mylib
---> Running in 23ccbff7b0dc
---> fa1e54d9cd1a
Removing intermediate container 23ccbff7b0dc
Step 3 : COPY classes /home/mylib
---> 730b80254d46
Removing intermediate container 5a145af08e07
Step 4 : WORKDIR /home/mylib
---> Running in a55c9e7387b5
---> 024f61681aa2
Removing intermediate container a55c9e7387b5
Step 5 : RUN chmod -R 755 /home/mylib && ls -l /home/mylib
---> Running in e84552bc63a0
total 0
drwxr-xr-x. 3 root root 23 Feb 1 16:19 com
---> 9f9ef5a68863
Removing intermediate container e84552bc63a0
Step 6 : CMD java com.mycompany.app.App
---> Running in 8119d7462f15
---> 5a791b689045
Removing intermediate container 8119d7462f15
Successfully built 5a791b689045

docker run:
hello !

#2. When package classes into jar, use jar in image, it doesn't work
Docker file:
FROM openjdk
RUN mkdir /home/mylib
COPY ./my-app-1.0-SNAPSHOT.jar /home/mylib
WORKDIR /home/mylib
RUN chmod -R 755 /home/mylib && ls -l /home/mylib
CMD ["java", “-cp /home/mylib/my-app-1.0-SNAPSHOT.jar”, "com.mycompany.app.App"]

Output:
Sending build context to Docker daemon 20.48 kB
Step 1 : FROM openjdk
---> 7c57090325cc
Step 2 : RUN mkdir /home/mylib
---> Running in 6d439987e509
---> f8f3e1bc604f
Removing intermediate container 6d439987e509
Step 3 : COPY ./my-app-1.0-SNAPSHOT.jar /home/mylib
---> 262f23fb541b
Removing intermediate container 484e0ac5e7a8
Step 4 : WORKDIR /home/mylib
---> Running in 913ed091bb95
---> a310b5f7a92b
Removing intermediate container 913ed091bb95
Step 5 : RUN chmod -R 755 /home/mylib && ls -l /home/mylib
---> Running in 0116e0e69b31
total 4
-rwxr-xr-x. 1 root root 2623 Feb 1 15:21 my-app-1.0-SNAPSHOT.jar
---> f3a1c08c4b93
Removing intermediate container 0116e0e69b31
Step 6 : CMD java -cp /home/mylib com.mycompany.app.App
---> Running in f12d02de8c9b
---> 72875b7ca1c6
Removing intermediate container f12d02de8c9b
Successfully built 72875b7ca1c6

docker run:
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

Why I can't use jar in this image?

Best regards

Lan

[snhrdt]

You should probably use

CMD ["java", "-cp",  "/home/mylib/my-app-1.0-SNAPSHOT.jar", "com.mycompany.app.App"]

Every single part of the command has to be specified on its own. This has nothing to do with this image but is true for every single docker image.

[lanliu99]

That should be the reason, I will test it later, thanks for the help.