mon: Add ceph osd get-require-min-compat-client command

As an antecedent to the already existing `get-require-min-compat-client`

Signed-off-by: hansbogert <hansbogert@gmail.com>

src/mon/MonCommands.h

@@ -704,6 +704,7 @@ COMMAND("osd set-nearfull-ratio " \
 	"name=ratio,type=CephFloat,range=0.0|1.0", \
 	"set usage ratio at which OSDs are marked near-full",
 	"osd", "rw", "cli,rest")
+COMMAND("osd get-require-min-compat-client", "get the minimum client version we will maintain compatibility with", "osd", "r", "cli,rest")
 COMMAND("osd set-require-min-compat-client " \
 	"name=version,type=CephString " \
 	"name=sure,type=CephChoices,strings=--yes-i-really-mean-it,req=false", \

src/mon/OSDMonitor.cc

@@ -8321,6 +8321,9 @@ bool OSDMonitor::prepare_command_impl(MonOpRequestRef op,
     wait_for_finished_proposal(op, new Monitor::C_Command(mon, op, 0, rs,
 					      get_last_committed() + 1));
     return true;
+  } else if (prefix == "osd get-require-min-compat-client") {
+    ss << "require_min_compat_client is set to " << ceph_release_name(osdmap.require_min_compat_client);
+    goto reply;
   } else if (prefix == "osd set-require-min-compat-client") {
     string v;
     cmd_getval(cct, cmdmap, "version", v);