Docker for Windows Community Edition
Version 18.06.1-ce-win73 (19507)
Windows 10 Version 1803 (OS Build 17134.286)
Summary
We are using docker-compose to create four containers that work together. The docker-compose configuration was authored on a Linux system and works fine there. But on a system running Docker for Windows as the daemon and using Windows Subsystem for Linux (WSL) for docker + docker-compose, the Java container in our set fails to load .jar files.
Details
We use docker-compose to spin up four containers–two for Mongo, one for our Node.JS front end and one for our Java-based back end. The first three are operating without any issues. The fourth instance, the Java back end, is haviing issues loading jar files using the java -jar <jarfile> syntax.
Both the front end and the back end get their source from the host by mapping the source tree directly into the image using the volume option in the docker-compose.yml file. The front-end works fine (i.e. Node.JS can load all the files that it needs to). But when java on the back end container tries to access the files that have been mapped into the image we see the following:
Exception in thread "main" java.lang.IllegalStateException: java.lang.IllegalArgumentException: File /home/spring-boot/application/target/backend.jar must exist
Problem is, the file does exist. docker exec-ing into the container I see the file there. But sure enough if I try to run java -jar backend.jar from the directory containing the file I get the same error. Java just doesn’t see it (or so I am led to believe).
Have searched the Internet but have had no luck figuring out what might be going on here. Any help would be greatly appreciated.
Here’s what I am seeing when I log into the container and try to run the .jar file directly:
root@c8495988284a:/home/spring-boot/application/target# ls -l
total 43584
drwxrwxrwx 2 root root 0 Sep 27 20:02 antrun
-rwxr-xr-x 1 root root 22309047 Sep 27 20:07 backend.jar
drwxrwxrwx 2 root root 0 Sep 27 20:02 classes
drwxrwxrwx 2 root root 0 Sep 27 20:02 generated-sources
drwxrwxrwx 2 root root 0 Sep 27 20:02 generated-test-sources
drwxrwxrwx 2 root root 0 Sep 27 20:02 maven-archiver
drwxrwxrwx 2 root root 0 Sep 27 20:02 maven-status
drwxrwxrwx 2 root root 0 Sep 27 20:02 surefire-reports
-rwxr-xr-x 1 root root 22309047 Sep 27 20:02 svc-backend-0.0.1-SNAPSHOT.jar
-rwxr-xr-x 1 root root 4100 Sep 27 20:02 svc-backend-0.0.1-SNAPSHOT.jar.original
drwxrwxrwx 2 root root 0 Sep 27 20:02 test-classes
root@c8495988284a:/home/spring-boot/application/target# java -jar backend.jar
Exception in thread "main" java.lang.IllegalStateException: java.lang.IllegalArgumentException: File /home/spring-boot/application/target/backend.jar must exist
at org.springframework.boot.loader.ExecutableArchiveLauncher.<init>(ExecutableArchiveLauncher.java:41)
at org.springframework.boot.loader.JarLauncher.<init>(JarLauncher.java:35)
at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:51)
Caused by: java.lang.IllegalArgumentException: File /home/spring-boot/application/target/backend.jar must exist
at org.springframework.boot.loader.data.RandomAccessDataFile$FileAccess.openIfNecessary(RandomAccessDataFile.java:234)
at org.springframework.boot.loader.data.RandomAccessDataFile$FileAccess.<init>(RandomAccessDataFile.java:216)
at org.springframework.boot.loader.data.RandomAccessDataFile$FileAccess.<init>(RandomAccessDataFile.java:206)
at org.springframework.boot.loader.data.RandomAccessDataFile.<init>(RandomAccessDataFile.java:49)
at org.springframework.boot.loader.jar.JarFile.<init>(JarFile.java:86)
at org.springframework.boot.loader.archive.JarFileArchive.<init>(JarFileArchive.java:60)
at org.springframework.boot.loader.archive.JarFileArchive.<init>(JarFileArchive.java:56)
at org.springframework.boot.loader.Launcher.createArchive(Launcher.java:129)
at org.springframework.boot.loader.ExecutableArchiveLauncher.<init>(ExecutableArchiveLauncher.java:38)
... 2 more
root@c8495988284a:/home/spring-boot/application/target# ls backend.jar
backend.jar
root@c8495988284a:/home/spring-boot/application/target#
And here’s a snippet from the docker-compose file:
backend:
image: "maven:3.5-jdk-10"
working_dir: /home/spring-boot
environment:
MONGODB_URI_LOCAL: mongodb://root:example@mongo
env: dev
volumes:
- ${SRCROOT:-.}/svc/backend:/home/spring-boot
expose:
- "8080"
ports:
- 8080:8080
command: "java -jar application/target/backend.jar"