fix(fd): close leaked file descriptors

[andrewazores]

Welcome to Cryostat! 👋

Before contributing, make sure you have:

• Read the contributing guidelines
• Linked a relevant issue which this PR resolves
• Linked any other relevant issues, PR's, or documentation, if any
• Resolved all conflicts, if any
• Rebased your branch PR on top of the latest upstream main branch
• Attached at least one of the following labels to the PR: [chore, ci, docs, feat, fix, test]
• Signed the last commit: git commit --amend --signoff

---

Fixes: #1444
Depends on cryostatio/cryostat-core#207 (these changes are really separate, but I want to update -core and include that dependency update in this same PR for simplicity)

Description of the change:

This simply closes some file descriptors that are currently leaked.

Motivation for the change:

Don't leak resources over time.

How to manually test:

See test procedure in cryostatio/cryostat-core#207 . Same thing applies. ls -l /proc/$pid/fd is useful for checking which descriptors look like they've been leaked. I used the following to ease tracing where those descriptors got opened:

https://github.com/jenkinsci/lib-file-leak-detector downloaded and placed into my cryostat/clientlib project directory, named as file-leak-detector.jar.

diff --git a/src/main/extras/app/entrypoint.bash b/src/main/extras/app/entrypoint.bash
index cd83fb51..2ed548ef 100755
--- a/src/main/extras/app/entrypoint.bash
+++ b/src/main/extras/app/entrypoint.bash
@@ -166,6 +166,8 @@ if [ -n "$CRYOSTAT_JUL_CONFIG" ]; then
     FLAGS+=("-Djava.util.logging.config.file=$CRYOSTAT_JUL_CONFIG")
 fi
 
+FLAGS+=("-javaagent:/clientlib/file-leak-detector.jar=threshold=200,trace,strong")
+

[tthvo]

Looks good! Another flanky credential tests :))

[github-actions]

This PR/issue depends on:

• fix(fs): close directory file descriptor cryostat-core#207
  By Dependent Issues (🤖). Happy coding!

[github-actions]

Test image available:

$ CRYOSTAT_IMAGE=ghcr.io/cryostatio/cryostat:pr-1445-8c2a54485e0b5f9f5fa80344560ddb8cdde385ac sh smoketest.sh