change domain names in kubernetes example to use localhost

Now that both chrome and firefox understand *.localhost domains we can
remove our suggestion of using localtest.me subdomains.

Also update the brew install instructions now that brew cask install
is deprecated in favor of brew install --cask

My favorite improvement is finding a way to use yaml block labels and
references to reduce the duplication in the ingress config.

I suppose the last important thing to mention about this changes is
that k3d seems to have switched from traefik to nginx for its ingress
loadbalancer. We no longer need the traefik annotation.

examples/k8s/README.md

@@ -5,7 +5,7 @@ using wiki to drive some learning about kubernetes.
 
 # We're using MacOS, Docker Desktop, and k3d
 
-    brew cask install docker
+    brew install --cask docker
     brew install k3d
 
     mkdir -p ~/.wiki-k8s ~/workspace/fedwiki
@@ -26,13 +26,16 @@ using wiki to drive some learning about kubernetes.
       "secure_cookie": false,
       "security_type": "friends",
       "wikiDomains": {
-        "simple.localtest.me": {
-          "id": "/home/node/.wiki/config.owner.json"
+        "localhost": {
+          "id": "/home/node/.wiki/localhost.owner.json"
+        },
+        "example.com": {
+          "id": "/home/node/.wiki/example.com.owner.json"
         }
       }
     }
 
-# example ~/.wiki-k8s/config.owner.json
+# example ~/.wiki-k8s/localhost.owner.json
 
 `.friend.secret` must match the `.admin` field from `config.json`
 
@@ -50,4 +53,4 @@ using wiki to drive some learning about kubernetes.
 
 # Play with the wiki
 
-    open http://simple.localtest.me
+    open http://wiki.localhost

examples/k8s/wiki.yaml

@@ -50,22 +50,15 @@ spec:
 apiVersion: extensions/v1beta1
 kind: Ingress
 metadata:
-  name: simple-wiki
-  annotations:
-    kubernetes.io/ingress.class: traefik
+  name: wiki
 spec:
   rules:
-  - host: simple.localtest.me
-    http:
-      paths:
-      - path: /
-        backend:
-          serviceName: wiki-service
-          servicePort: http
-  - host: "*.simple.localtest.me"
-    http:
+  - host: "*.localhost"
+    http: &wiki
       paths:
       - path: /
         backend:
           serviceName: wiki-service
           servicePort: http
+  # - host: "*.example.com"
+  #   http: *wiki