Resolves mismatched cluster names on envoy_stats

Signed-off-by: Alexis <[email protected]>

python/ambassador/diagnostics/diagnostics.py

@@ -118,8 +118,10 @@ def __init__(self, diag: "Diagnostics", estat: EnvoyStats, request) -> None:
 
         # Go ahead and grab Envoy cluster stats for all possible clusters.
         # XXX This might be a bit silly.
-        self.cluster_names = [cluster.envoy_name for cluster in self.diag.clusters.values()]
-        self.cstats = {name: self.estat.cluster_stats(name) for name in self.cluster_names}
+        self.cstats = {
+            cluster.envoy_name: self.estat.cluster_stats(cluster.stats_name)
+            for cluster in self.diag.clusters.values()
+        }
 
         # Save the request host and scheme. We'll need them later.
         self.request_host = request.headers.get("Host", "*")