elasticsearch: copy plugins to dataDir

[shivaraj-bh]

resolves #325

[shivaraj-bh]

@secobarbital can you check if this works for you?

Also, I have included a test to check for plugin installation.

[secobarbital]

Wow, thank you for the quick turnaround! Yes, this does work for me, it is almost the same as the workaround I came back to report:

                cp -RL ${esPlugins}/plugins "${config.dataDir}"
                find "${config.dataDir}/plugins" -type d -exec chmod u+w {} \;

I find that only the directories needed their permissions fixed to get it to work, not the files.

However, I also found this in the official elasticsearch Dockerfile and I wonder if we should follow their permissions as canonical. It looks like they intentionally package the files and directories with no permissions and expect consumer to modify them?

RUN sed -i -e 's/ES_DISTRIBUTION_TYPE=tar/ES_DISTRIBUTION_TYPE=docker/' bin/elasticsearch-env && \
    mkdir data && \
    mv config/log4j2.properties config/log4j2.file.properties && \
    mv config/log4j2.docker.properties config/log4j2.properties && \
    find . -type d -exec chmod 0555 {} + && \
    find . -type f -exec chmod 0444 {} + && \
    chmod 0555 bin/* jdk/bin/* jdk/lib/jspawnhelper modules/x-pack-ml/platform/linux-*/bin/* && \
    chmod 0775 bin config config/jvm.options.d data logs plugins && \
    find config -type f -exec chmod 0664 {} +

[secobarbital]

This works! Coupa of slight tweaks to suggest.

[shivaraj-bh]

Thanks @secobarbital