daemons: Log POSIX signal names alongside their numbers in handlers

Closes #6225

Signed-off-by: Andrii Sultanov <[email protected]>

ocaml/networkd/bin/dune

@@ -15,6 +15,7 @@
  (libraries
   astring
   clock
+  fmt
   forkexec
   http_lib
   integers

ocaml/networkd/bin/network_server.ml

@@ -53,7 +53,9 @@ let on_shutdown signal =
   let dbg = "shutdown" in
   Debug.with_thread_associated dbg
     (fun () ->
-      debug "xcp-networkd caught signal %d; performing cleanup actions." signal ;
+      debug "xcp-networkd caught signal %s (%d); performing cleanup actions."
+        Fmt.(to_to_string Dump.signal signal)
+        signal ;
       write_config ()
     )
     ()

ocaml/xcp-rrdd/bin/rrdd/dune

@@ -44,6 +44,7 @@
 
     ezxenstore.core
     ezxenstore.watch
+    fmt
     forkexec
     http_lib
     httpsvr

ocaml/xcp-rrdd/bin/rrdd/xcp_rrdd.ml

@@ -735,7 +735,7 @@ let configure_writers () =
 (** we need to make sure we call exit on fatal signals to make sure profiling
     data is dumped *)
 let stop err writers signal =
-  debug "caught signal %d" signal ;
+  debug "caught signal %s (%d)" Fmt.(to_to_string Dump.signal signal) signal ;
   List.iter (fun (_, writer) -> writer.Rrd_writer.cleanup ()) writers ;
   exit err
 

ocaml/xenopsd/lib/xenopsd.ml

@@ -460,7 +460,10 @@ let main backend =
   in
   (* we need to catch this to make sure at_exit handlers are triggered. In
      particuar, triggers for the bisect_ppx coverage profiling *)
-  let signal_handler n = debug "caught signal %d" n ; exit 0 in
+  let signal_handler n =
+    debug "caught signal %s (%d)" Fmt.(to_to_string Dump.signal n) n ;
+    exit 0
+  in
   Sys.set_signal Sys.sigpipe Sys.Signal_ignore ;
   Sys.set_signal Sys.sigterm (Sys.Signal_handle signal_handler) ;
   Xenops_utils.set_fs_backend