Make upstream naming more general

roles/whoami/templates/upstream.json.j2

@@ -0,0 +1,30 @@
+{
+    "@id": "{{ stack.name }}_upstream",
+{% if domain is not undefined and not none %}   
+    "match": [
+        {
+            "host": [
+                "{{ stack.name }}.{{ domain }}"
+            ]
+        }
+    ],
+{% else %}
+    "match": [
+        {
+            "path": [
+                "/{{ stack.name }}*"
+            ]
+        }
+    ],
+{% endif %}
+    "handle": [
+        {
+            "handler": "reverse_proxy",
+            "upstreams": [
+                {
+                    "dial": "{{ stack.name }}_app:80"
+                }
+            ]
+        }
+    ]
+}