The leader_host API handler was eventually using the `req` unique_ptr
after it has been already destroyed (passed down to the future lambda
by reference). This was causing an occassional crash in some tests.
Reworked the leader_host handler to use the req only outside of the
future lambda.
Also updated the code to handle the possibility that the non-default
leader group (other than Group 0) might reside on a different shard
than the shard 0 - using the same concept of calling on all shards via
`invoke_on_all()` as done for the other requests.
Fixesscylladb/scylladb#19714
(cherry picked from commit b2db8f4b9b)
Closesscylladb/scylladb#19742
The API req->param["name"] to access parameters in the path part of the
URL was buggy - it forgot to do URL decoding and the result of our use
of it in Scylla was bugs like #5883 - where special characters in certain
REST API requests got botched up (encoded by the client, then not
decoded by the server).
The solution is to replace all uses of req->param["name"] by the new
req->get_path_param("name"), which does the decoding correctly.
Unfortunately we needed to change 104 (!) callers in this patch, but the
transformation is mostly mechanical and there is no functional changes in
this patch. Another set of changes was to bring req, not req->param, to
a few functions that want to get the path param.
This patch avoids the numerous deprecation warnings we had before, and
more importantly, it fixes#5883.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
This uses the `trigger_snapshot()` API added in previous commit on a
server running for the given Raft group.
It can be used for example in tests or in the context of disaster
recovery (ref scylladb/scylladb#16683).
