[Story] "Test connection" feature

[andrewazores]

As a user, I do not want to have to update a connection configuration, attempt to load a content view, and then delete and recreate my connection configuration if I entered the wrong values by mistake.

• [Task] Add "test connection" button to JMX Credentials creation form #593
• [Task] Add "test connection" button to Custom Target creation modal #594

[tthvo]

Looks like we need to define an API endpoint to open a probe connection to the target. Just wondering if we can safely use any existing endpoint for this purpose?

Maybe reusing the v2/targets with verb POST to specify a parameter ?probe=true and the backend can stop before adding the target to discovery tree?

[andrewazores]

I think reusing the existing custom targets definition endpoint makes sense. I would probably call the parameter dryrun or something, but probe could work too - though we already use that term in relation to the JMC Agent and inserting bytecode.

That endpoint handler is already basically set up to do what we need it to, since it will attempt to open a connection to the target and retrieve its hash ID before adding it to the discovery database. So the probe/dryrun parameter would just skip that last step. It looks like the handler also needs to notify the JVM ID cache to invalidate the ID entry if the definition is not actually added to the database, or maybe instead a way to retrieve the JVM ID without caching the result to begin with.