Your Feature Request

Dumping variables for debugging is not an easy thing, neither is placing many of them in a header to pass to an application, or to a monitoring system.

Something convenient would consist in having a dump_all_vars([scope],[prefix]) sample fetch function that produces a list of all variables matching optional scope and optional prefix, in the form var=val, ... for example, possibly with quotes for text ones. It would be particularly handy for those retrieved from stick-tables as described in #1620; in a single request from a monitoring system, an http-request return rule could dump all the counters associated with a given key for example.

The syntax should be made evolutive so that an extension could quickly be added to specify the output format (e.g. produce a JSON-formatted list).

What are you trying to do?

Ease extraction of multiple variables at once without having to repeat their names everywhere and on every line when they all begin with a distinguishable prefix.

Output of haproxy -vv

Would be a nice to have for 2.6. It's supposed not to be difficult to implement.