graylog: improve JRE handling

[lheckemann]

Motivation for this change

Since the upstream graylogctl script will prefer finding its java
executable based on JAVA_HOME, we now set this instead of PATH in
order to allow it to find the JRE. By setting it conditionally on it
not already being set, we allow selecting a different JRE at runtime.

Things done

• Tested nixos/tests/graylog.nix
• Fits CONTRIBUTING.md.

[r-rmcgibbo]

Result of nixpkgs-review pr 117809 at 52a82e3 run on x86_64-linux 1

1 package built successfully:

• graylog

2 suggestions:

• warning: missing-phase-hooks

  installPhase should probably contain runHook preInstall and runHook postInstall.

  Near pkgs/tools/misc/graylog/default.nix:20:3:

     |
  20 |   installPhase = ''
     |   ^
  

• warning: unclear-gpl

  gpl3 is a deprecated license, please check if project uses gpl3Plus or gpl3Only and change meta.license accordingly.

  Near pkgs/tools/misc/graylog/default.nix:29:5:

     |
  29 |     license     = licenses.gpl3;
     |     ^
  

---

Result of nixpkgs-review pr 117809 at 52a82e3 run on aarch64-linux 1

1 package built successfully:

• graylog

2 suggestions:

• warning: missing-phase-hooks

  installPhase should probably contain runHook preInstall and runHook postInstall.

  Near pkgs/tools/misc/graylog/default.nix:20:3:

     |
  20 |   installPhase = ''
     |   ^
  

• warning: unclear-gpl

  gpl3 is a deprecated license, please check if project uses gpl3Plus or gpl3Only and change meta.license accordingly.

  Near pkgs/tools/misc/graylog/default.nix:29:5:

     |
  29 |     license     = licenses.gpl3;
     |     ^
  

[SuperSandro2000]

@lheckemann tests fail in ofborg

[Ma27]

And it's not transient:

machine # [   21.094467] graylogctl[999]: which: no java in (/nix/store/b86fbamwswj596c1md5f0sh0a5wsbz8x-which-2.21/bin:/nix/store/yyw2db5czblg7k86py43x0628w157p8x-procps-3.3.16/bin:/nix/store/15gmaah0dihis48xpr4nlm50giwlv403-libressl-3.2.5-nc/bin:/nix/store/9fkdn82nzxgkxyax3m9qdh2knj7apaa5-coreutils-8.32/bin:/nix/store/7nx8fqzpi5nsbi07md1qb1gbf9fscf9i-findutils-4.7.0/bin:/nix/store/ia1dn8zyi07phxkx02c0wwqc7v7c54nl-gnugrep-3.6/bin:/nix/store/ij7k48dhdrda13gcp3lbpi507b2awnmr-gnused-4.8/bin:/nix/store/caz5k18ar764161b0amywc002cp39lgx-systemd-247.3/bin:/nix/store/b86fbamwswj596c1md5f0sh0a5wsbz8x-which-2.21/sbin:/nix/store/yyw2db5czblg7k86py43x0628w157p8x-procps-3.3.16/sbin:/nix/store/15gmaah0dihis48xpr4nlm50giwlv403-libressl-3.2.5-nc/sbin:/nix/store/9fkdn82nzxgkxyax3m9qdh2knj7apaa5-coreutils-8.32/sbin:/nix/store/7nx8fqzpi5nsbi07md1qb1gbf9fscf9i-findutils-4.7.0/sbin:/nix/store/ia1dn8zyi07phxkx02c0wwqc7v7c54nl-gnugrep-3.6/sbin:/nix/store/ij7k48dhdrda13gcp3lbpi507b2awnmr-gnused-4.8/sbin:/nix/store/caz5k18ar764161b0amywc002cp39lgx-systemd-247.3/sbin)
machine: waiting for TCP port 9000
machine # [   21.532366] graylogctl[995]: Running graylog-server ...
machine # [   21.540196] graylogctl[995]: Unrecognized VM option 'UseConcMarkSweepGC'
machine # [   21.541386] graylogctl[995]: Error: Could not create the Java Virtual Machine.
machine # [   21.542246] graylogctl[995]: Error: A fatal exception has occurred. Program will exit.
machine # [   21.545431] systemd[1]: graylog.service: Main process exited, code=exited, status=1/FAILURE
machine # [   21.546462] systemd[1]: graylog.service: Failed with result 'exit-code'.
machine # [   21.547379] systemd[1]: graylog.service: Consumed 222ms CPU time, no IO, received 1.0K IP traffic, sent 1.4K IP traffic.