Add README for VirtualServices

.github/workflows/test.yml

@@ -13,6 +13,7 @@ jobs:
         run: |
            curl -L https://github.com/yannh/kubeconform/releases/latest/download/kubeconform-linux-amd64.tar.gz | tar -zxf -
            sudo mv kubeconform /usr/local/bin
+           kubeconform -v
       - name: check all yaml
         run: |
           ./bin/test.sh | tee -a apply.txt

Istio/VirtualService/README.md

@@ -0,0 +1,10 @@
+# VirtualService
+`VirtualServices` configure routing rules for traffic.
+
+Traffic is identified by the _Host_ it's addressed to in its layer 7 request header (there must be at most one VirtualService per Host).
+For a given protocol, Routing Rules are then tried in order until one matches the attributes of the request.
+The matching routing rule specifies a Service to which to send the request (a _Service_ is effectively a Kubernetes `Service`, qv).
+Optionally, a subset of the Service's Pods can be targeted using Subsets (see `DestinationRule`)
+
+VirtualServices can be thought of as an "active" bump-on-the-wire through which requests are sent.
+They can apply various transforms to the traffic passing through them, such as header manipulation, delay injection, etc.