RFR: 8237: Add support for Jolokia over Kubernetes proxy

[Martin Skarsaune]

On Sun, 4 Aug 2024 12:05:24 GMT, Martin Skarsaune <duke at openjdk.org> wrote:

> JMC-8273 : Use the jolokia protocol over a kubernetes http proxy.
> 
> Testing connectivity:
> - [x]  Docker desktop kubernetes 
> - [x]  Azure AKS
> - [x]  Amazon EKS
> - [x]  Google GKE
> 
> Other things observed:
> 
> - [x] * Option to install agent should be disabled (debug difference with jolokia) - ***see below****
> - [x] * Warning: NLS missing message: JmcKubernetesPreferenceForm_LogErrorsTooltip in: org.openjdk.jmc.kubernetes.preferences.messages
> - [x] * SLF4J(W): No SLF4J providers were found. ***OK for now, can investigate more later***
> SLF4J(W): Defaulting to no-operation (NOP) logger implementation
> SLF4J(W): See https://www.slf4j.org/codes.html#noProviders for further details.
> - [x] Unlocking secrets now appear on startup. Should not be needed unless there are credentials used. (fixed)

The cause for the log initialization output is calling `Utils.getSystemPropertyOrEnvVar` . That is only used very briefly for that very particular use. Can look for alternatives.

Found the "issue" with the JMC agent. 

`	public boolean isLocalJvm() {
		return connectionHandle.getServerDescriptor().getJvmInfo() != null;
	}`
Will experiment with not providing getJvmInfo for jolokia and kubernetes

Finding on the Jolokia side. When probing connection k8s API authorization is missing. This can be fixed by using fabric8 http client instead of using OK Http directly.

Have been able to fix kubernetes client in Jolokia, however basic auth for jolokia with special header fails.

-------------

PR Comment: https://git.openjdk.org/jmc/pull/576#issuecomment-2439913142
PR Comment: https://git.openjdk.org/jmc/pull/576#issuecomment-2445352245
PR Comment: https://git.openjdk.org/jmc/pull/576#issuecomment-2568151073
PR Comment: https://git.openjdk.org/jmc/pull/576#issuecomment-2568962412