Warn on infrastructure-roles.yaml format violations (#177)

Emit a warning if there are unprocessed entries in the infrastructure-roles secret.

pkg/controller/util.go

@@ -137,6 +137,8 @@ Users:
 					c.logger.Warningf("unknown key %q", p)
 				}
 			}
+
+			delete(data, key)
 		}
 
 		if t.Name != "" {
@@ -144,6 +146,12 @@ Users:
 		}
 	}
 
+	if len(data) != 0 {
+		c.logger.Warningf("%d unprocessed entries in the infrastructure roles' secret", len(data))
+		c.logger.Info(`infrastructure role entries should be in the {key}{id} format, where {key} can be either of "user", "password", "inrole" and the {id} a monotonically increasing integer starting with 1`)
+		c.logger.Debugf("unprocessed entries: %#v", data)
+	}
+
 	return result, nil
 }