[discuss] unify launch scripts options support

[colinsurprenant]

The new Windows launch scripts in #8178 is changing some behaviours from the Linux launch scripts:

• existing JAVA_OPTS env var is now ignored, ES is also doing this
• JAVA_TOOL_OPTIONS env var is cleared, ES is also doing this
• now only LS_JAVA_OPTS env var is supported to append options to parsed options in the jvm.options file.
• dropped the support of the USE_RUBY and USE_DRIP env vars. These not used anymore I believe.

My proposal is to also apply these changes to the Linux launch scripts.
WDYT?

[jordansissel]

I still use USE_RUBY but only as a desparate workaround. I am OK if it is removed.

+1 on unifying (it should make user experience better, documentation easier, and maintenance simpler)

[original-brownbear]

+1 also makes #8161 much easier (replicating the current shell behaviour there turned out to be very tricky :))

[jakelandis]

+1 to unify, and +1 to make the 6.0.0 release, since this is non-passive.

[jordansissel]

@jakelandis it's a bit late in the game for 6.0.0, but if we feel confident in the change (once merged), I would be OK with it landing for 6.0.0 (assuming the ship hasn't already sailed).

[suyograo]

+1 to all your points. We should get this for 6.0 if possible.

[ph]

+1 to everything , +1 for 6.0 release.

[colinsurprenant]

ok, lets do this, quorum is met 😅

[colinsurprenant]

PR in #8285

[colinsurprenant]

#8285 new Linux launch scripts merged in master, 6.x and 6.0