Windows: CrateDB fails to start on Docker for Windows with `-Cdiscovery.type=single-node`

[amotl]

@michaelkremmel reported this the other day. Thank you.

Problem

After executing the command docker run --name=cratedb --rm -it --network=cratedb-demo --publish=4200:4200 --publish=5432:5432 --env=CRATE_HEAP_SIZE=2g docker.io/crate -Cdiscovery.type=single-node I got the following warning and it was not clear to me what it means or if it could affect anything I tried to achieve with the tutorial.

WARNING: Using incubator modules: jdk.incubator.vector
Exception in thread "main" java.lang.NullPointerException: Cannot invoke "String.isEmpty()" because "kvp.value" is null
        at io.crate.server.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:67)
        at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:120)
        at org.elasticsearch.cli.Command.main(Command.java:86)
        at io.crate.bootstrap.CrateDB.main(CrateDB.java:68)

Workaround

Turned out that the CrateDB container run only for a few seconds and stopped. After some trial and error I just removed -Cdiscovery.type=single-node which made it work, however I'm not sure what implications that has, so please don't consider it as a fix, but just as a workaround from my side and if possible find out what is causing the issue.

[amotl]

If CrateDB fails to start because it raises an NPE Cannot invoke "String.isEmpty()" because "kvp.value" is null when used with -Cdiscovery.type=single-node on Docker for Windows, it might satisfy to create a ticket at crate/crate to possibly investigate and resolve?

/cc @jeeminso, @matriv, @seut

[matriv]

If CrateDB fails to start because it raises an NPE Cannot invoke "String.isEmpty()" because "kvp.value" is null when used with -Cdiscovery.type=single-node on Docker for Windows, it might satisfy to create a ticket at crate/crate to possibly investigate and resolve?

/cc @jeeminso, @matriv, @seut

This is happening only on windows?

[amotl]

Hi @matriv. I've just cherry-picked and forwarded this here, the observation was made by @michaelkremmel using Docker on Windows a month ago already. I don't know about other explorations, e.g. "Windows-native" walkthrough attempts.

Please also note this is currently "just" a documentation bug, to be elevated only at your disposal. CrateDB starts well when omitting the -Cdiscovery.type=single-node CLI option.

[michaelkremmel]

@matriv Yes, it only happened on my Windows machine. I tried it on other devices (e.g., a RaspberryPI) and there I didn't face any issues. If I have removed -Cdiscovery.type=single-node it was also working well on my Windows machine. Thank you for creating the ticket @amotl.

[michaelkremmel]

@matriv I could test it now also with another Windows machine, resulting in the same error. I opened a ticket in crate/crate as you suggested.

• CrateDB fails to start on Windows with -Cdiscovery.type=single-node crate#18378

[amotl]

GH-367 removes the option from the docs until further notice, please re-evaluate the situation.