fix: try-catch for unknow reason to inhibit api crash

apps/emqx_prometheus/src/emqx_prometheus.erl

@@ -883,6 +883,7 @@ gen_point(Type, Name, Path) ->
 %% TODO: cert manager for more generic utils functions
 cert_expiry_at_from_path(Path0) ->
     Path = emqx_schema:naive_env_interpolation(Path0),
+    try
         case file:read_file(Path) of
             {ok, PemBin} ->
                 [CertEntry | _] = public_key:pem_decode(PemBin),
@@ -891,7 +892,24 @@ cert_expiry_at_from_path(Path0) ->
                 {'utcTime', NotAfterUtc} =
                     Cert#'Certificate'.'tbsCertificate'#'TBSCertificate'.validity#'Validity'.'notAfter',
                 utc_time_to_epoch(NotAfterUtc);
-        {error, _} ->
+            {error, Reason} ->
+                ?SLOG(error, #{
+                    msg => "read_cert_file_failed",
+                    path => Path0,
+                    resolved_path => Path,
+                    reason => Reason
+                }),
+                0
+        end
+    catch
+        E:R ->
+            ?SLOG(error, #{
+                msg => "obtain_cert_expiry_time_failed",
+                error => E,
+                reason => R,
+                path => Path0,
+                resolved_path => Path
+            }),
             0
     end.