kresctl: add message when Prometheus is missing

diff --git a/manager/knot_resolver_manager/cli/cmd/metrics.py b/manager/knot_resolver_manager/cli/cmd/metrics.py
index c535186ef131f223496951538376cc51218facf2..7f466ec30f5498c1328e0bbaeec716a5d0785e86 100644 (file)
--- a/manager/knot_resolver_manager/cli/cmd/metrics.py
+++ b/manager/knot_resolver_manager/cli/cmd/metrics.py
@@ -62,4 +62,6 @@ class MetricsCommand(Command):
                 print(metrics)
         else:
             print(response, file=sys.stderr)
+            if self.prometheus and response.status == 404:
+                print("Prometheus is unavailable due to missing optional dependencies", file=sys.stderr)
             sys.exit(1)