kube: standardize on a `local ns` convention

A convention is introduced to specify the kube.Namespace object in a deployment as a `local ns` instead of an `ns:` or a `namespace:` for these reasons:

- non-cluster admins cannot create new namespaces, and we've been moving in the direction of specifying objects that require cluster admin permissions to apply (policies, role bindings) in //cluster/kube/k0 instead of in the app jsonnet
- namespace admins CAN delete the namespace, making `kubecfg delete` unexpectedly dangerous (especially if a namespace contains more than just the contents of the file being applied - common with personal namespaces)
- `.Contain()` is a common operation, and it shows up in lines that are pretty long, so `ns.Contain()` is preferable to `app.ns.Contain()` or `service.namespace.Contain()`

Change-Id: Ie4ea825376dbf6faa175179054f3ee3de2253ae0
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1804
Reviewed-by: q3k <q3k@hackerspace.pl>
diff --git a/app/matrix/lib/wellknown.libsonnet b/app/matrix/lib/wellknown.libsonnet
index 509b83c..1760e01 100644
--- a/app/matrix/lib/wellknown.libsonnet
+++ b/app/matrix/lib/wellknown.libsonnet
@@ -11,8 +11,9 @@
     },
 
     ns:: error "ns needs to be a kube.Namespace object",
+    local ns = app.ns,
 
-    deployment: app.ns.Contain(kube.Deployment("wellknown")) {
+    deployment: ns.Contain(kube.Deployment("wellknown")) {
         spec+: {
             replicas: 1,
             template+: {
@@ -35,7 +36,7 @@
             },
         },
     },
-    svc: app.ns.Contain(kube.Service("wellknown")) {
+    svc: ns.Contain(kube.Service("wellknown")) {
         target:: app.deployment,
     },
 }