Avoid overwriting JAVA_HOME by IDEA

[azatsarynnyy]

What does this PR do?

In the UDI image, /home/user/.java is a JAVA_HOME.
IDEA editor is overwriting that directory by its config.
This patch changes the IDEA config path.

What issues does this PR fix or reference?

https://issues.redhat.com/browse/CRW-4525

Release Notes

Docs PR (if applicable)

[l0rd]

@azatsarynnyy shouldn't you update JetBrains IDEs config to reflect that now projector Java configuration is in ${HOME}/.projector-java?

[azatsarynnyy]

@azatsarynnyy shouldn't you update JetBrains IDEs config to reflect that now projector Java configuration is in ${HOME}/.projector-java?

@l0rd Sorry, I didn't get your idea about updating the JetBrains IDEs config. Do you mean this environment variable?

- name: PROJECTOR_CONFIG_DIR
  value: /home/user/.jetbrains

Why do you think we need to change it?

[l0rd]

What I mean is that projector is currently using the folder ~/.java to store its configuration. The fact that you have changed the folder of the volume doesn't affect projector configuration: the folder ~/.projector-java will be persisted but I suspect that projector will continue to write its configuration in ~/.java.

[azatsarynnyy]

Yes, we need to tell our Jetbrains editors to use another folder.
I checked why do we need a volume for it:
JetBrains IDEs store some values to java preferences. Like accepted EULA.
On Linux, Java Preferences API storage is in the $HOME/.java/.userPrefs/prefs.xml directory, by default.
Having a volume for /home/user/.java allows restoring such java preferences for IDEA across workspace restarts.

The only idea I have for now is passing something like -Djava.util.prefs.systemRoot=/home/user/.projector-java when running IDE. But it seems too fragile for me.

[l0rd]

The only idea I have for now is passing something like -Djava.util.prefs.systemRoot=/home/user/.projector-java when running IDE. But it seems too fragile for me.

Why do you think it's fragile? What could go wrong?

Also another alternative is to copy $HOME/.java/.userPrefs/prefs.xml to $HOME/.jetbrains at container startup and restore it at startup...