Provide default directory for js plugins

[devinrsmith]

I'd like to consider moving towards a model where "if you follow directory conventions, you don't need to explicitly set configuration properties".

As a motivating example, I'd like consumers of our docker images to install a JS plugins without needing to explicitly include a configuration property (file or system property).

# syntax=docker/dockerfile:1.4

FROM ghcr.io/deephaven/web-plugin-packager:latest as build
RUN ./pack-plugins.sh @deephaven/js-plugin-matplotlib

FROM ghcr.io/deephaven/server:latest
RUN pip install deephaven-plugin-matplotlib
COPY --link --from=build js-plugins/ /opt/deephaven/config/js-plugins/

As it stands now, the user would either need to explicitly add deephaven.prop:

includefiles=dh-defaults.prop

deephaven.jsPlugins.resourceBase=/opt/deephaven/config/js-plugins

COPY --link deephaven.prop /opt/deephaven/config/deephaven.prop

or, add a system property (which I want to try and discourage as much as possible):

ENV START_OPTS="-Ddeephaven.jsPlugins.resourceBase=/opt/deephaven/config/js-plugins"

This example is based off of deephaven-examples/deephaven-matplotlib-base#3

[devinrsmith]

Would be able to update and simplify https://github.com/deephaven/deephaven.io/pull/1947

[mofojed]

@devinrsmith Can we log some feedback on what JS plugin directory was loaded? Right now it doesn't print anything, and as someone trying it out I don't know what directory it's checking, or what directory was loaded, etc.
For example, if I'm running:

 DEEPHAVEN_DATA_DIR=/Users/bender/tmp/deephaven-data ./gradlew server-jetty-app:run

What directory is being used for js-plugins? I have no idea, I tried putting a manifest.json in /Users/bender/tmp/deephaven-data/js-plugins/manifest.json and at /Users/bender/tmp/deephaven-data/storage/js-plugins/manifest.json, and it didn't seem to pick it up. I really don't know where this is actually looking.

[devinrsmith]

This is a fine feature request, irrespective of this PR IMO.

Y̶o̶u̶ ̶c̶a̶n̶'̶t̶ ̶p̶a̶s̶s̶ ̶e̶n̶v̶i̶r̶o̶n̶m̶e̶n̶t̶ ̶v̶a̶r̶i̶a̶b̶l̶e̶s̶ ̶t̶h̶r̶o̶u̶g̶h̶ ̶̶.̶/̶g̶r̶a̶d̶l̶e̶w̶ ̶.̶.̶.̶̶ ̶b̶t̶w̶,̶ ̶t̶h̶a̶t̶'̶s̶ ̶n̶o̶t̶ ̶b̶e̶e̶n̶ ̶a̶ ̶f̶e̶a̶t̶u̶r̶e̶ ̶w̶e̶'̶v̶e̶ ̶s̶u̶p̶p̶o̶r̶t̶e̶d̶.̶ ̶

Edit: my bad, you can pass environment variables through ./gradlew ..., so DEEPHAVEN_DATA_DIR=/my/path ./gradlew ... does work. (Note: START_OPTS and JAVA_OPTS are bash script environment variables not applicable to the java process, so they would need a different approach, see #3220)

[devinrsmith]

@mofojed - if you try your previous run with DEEPHAVEN_CONFIG_DIR instead of DEEPHAVEN_DATA_DIR, I think it will work.

[mofojed]

Setting DEEPHAVEN_CONFIG_DIR instead of DEEPHAVEN_DATA_DIR worked.

[deephaven-internal]

Labels indicate documentation is required. Issues for documentation have been opened:

How-to: https://github.com/deephaven/deephaven.io/issues/2039
Conceptual: https://github.com/deephaven/deephaven.io/issues/2041
Reference: https://github.com/deephaven/deephaven.io/issues/2040
Blog: https://github.com/deephaven/deephaven.io/issues/2042