Switch language name 'zh' to 'zh-cn'

This is the first step to rename 'zh' to 'zh-cn'. There are several reasons why we rename the language name.

- The upstream docsy theme changed the language name, leading to many warnings during site build;
  The side-effect is that the i18n strings are no longer working.
- We believe renaming the language is the right thing to do, because this move can make room for other variants of Chinese language, such as 'zh-tw', 'zh-sg' etc.

There would be several follow-ups to this PR, such as fixing the intra-site links, adding redirects etc.

We will lock up changes to zh/zh-cn pages for the moment, until this one gets in.

This PR is based on commit cdad0a7342.

content/zh-cn/examples/admin/konnectivity/egress-selector-configuration.yaml

@@ -0,0 +1,21 @@
+apiVersion: apiserver.k8s.io/v1beta1
+kind: EgressSelectorConfiguration
+egressSelections:
+# Since we want to control the egress traffic to the cluster, we use the
+# "cluster" as the name. Other supported values are "etcd", and "master".
+- name: cluster
+  connection:
+    # This controls the protocol between the API Server and the Konnectivity
+    # server. Supported values are "GRPC" and "HTTPConnect". There is no
+    # end user visible difference between the two modes. You need to set the
+    # Konnectivity server to work in the same mode.
+    proxyProtocol: GRPC
+    transport:
+      # This controls what transport the API Server uses to communicate with the
+      # Konnectivity server. UDS is recommended if the Konnectivity server
+      # locates on the same machine as the API Server. You need to configure the
+      # Konnectivity server to listen on the same UDS socket.
+      # The other supported transport is "tcp". You will need to set up TLS 
+      # config to secure the TCP transport.
+      uds:
+        udsName: /etc/kubernetes/konnectivity-server/konnectivity-server.socket

content/zh-cn/examples/admin/konnectivity/konnectivity-agent.yaml

@@ -0,0 +1,55 @@
+apiVersion: apps/v1
+# Alternatively, you can deploy the agents as Deployments. It is not necessary
+# to have an agent on each node.
+kind: DaemonSet
+metadata:
+  labels:
+    addonmanager.kubernetes.io/mode: Reconcile
+    k8s-app: konnectivity-agent
+  namespace: kube-system
+  name: konnectivity-agent
+spec:
+  selector:
+    matchLabels:
+      k8s-app: konnectivity-agent
+  template:
+    metadata:
+      labels:
+        k8s-app: konnectivity-agent
+    spec:
+      priorityClassName: system-cluster-critical
+      tolerations:
+        - key: "CriticalAddonsOnly"
+          operator: "Exists"
+      containers:
+        - image: us.gcr.io/k8s-artifacts-prod/kas-network-proxy/proxy-agent:v0.0.16
+          name: konnectivity-agent
+          command: ["/proxy-agent"]
+          args: [
+                  "--logtostderr=true",
+                  "--ca-cert=/var/run/secrets/kubernetes.io/serviceaccount/ca.crt",
+                  # Since the konnectivity server runs with hostNetwork=true,
+                  # this is the IP address of the master machine.
+                  "--proxy-server-host=35.225.206.7",
+                  "--proxy-server-port=8132",
+                  "--admin-server-port=8133",
+                  "--health-server-port=8134",
+                  "--service-account-token-path=/var/run/secrets/tokens/konnectivity-agent-token"
+                  ]
+          volumeMounts:
+            - mountPath: /var/run/secrets/tokens
+              name: konnectivity-agent-token
+          livenessProbe:
+            httpGet:
+              port: 8134
+              path: /healthz
+            initialDelaySeconds: 15
+            timeoutSeconds: 15
+      serviceAccountName: konnectivity-agent
+      volumes:
+        - name: konnectivity-agent-token
+          projected:
+            sources:
+              - serviceAccountToken:
+                  path: konnectivity-agent-token
+                  audience: system:konnectivity-server

content/zh-cn/examples/admin/konnectivity/konnectivity-rbac.yaml

@@ -0,0 +1,24 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: system:konnectivity-server
+  labels:
+    kubernetes.io/cluster-service: "true"
+    addonmanager.kubernetes.io/mode: Reconcile
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: system:auth-delegator
+subjects:
+  - apiGroup: rbac.authorization.k8s.io
+    kind: User
+    name: system:konnectivity-server
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: konnectivity-agent
+  namespace: kube-system
+  labels:
+    kubernetes.io/cluster-service: "true"
+    addonmanager.kubernetes.io/mode: Reconcile

content/zh-cn/examples/admin/konnectivity/konnectivity-server.yaml

@@ -0,0 +1,72 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: konnectivity-server
+  namespace: kube-system
+spec:
+  priorityClassName: system-cluster-critical
+  hostNetwork: true
+  containers:
+  - name: konnectivity-server-container
+    image: us.gcr.io/k8s-artifacts-prod/kas-network-proxy/proxy-server:v0.0.16
+    command: ["/proxy-server"]
+    args: [
+            "--logtostderr=true",
+            # This needs to be consistent with the value set in egressSelectorConfiguration.
+            "--uds-name=/etc/kubernetes/konnectivity-server/konnectivity-server.socket",
+            # The following two lines assume the Konnectivity server is
+            # deployed on the same machine as the apiserver, and the certs and
+            # key of the API Server are at the specified location.
+            "--cluster-cert=/etc/kubernetes/pki/apiserver.crt",
+            "--cluster-key=/etc/kubernetes/pki/apiserver.key",
+            # This needs to be consistent with the value set in egressSelectorConfiguration.
+            "--mode=grpc",
+            "--server-port=0",
+            "--agent-port=8132",
+            "--admin-port=8133",
+            "--health-port=8134",
+            "--agent-namespace=kube-system",
+            "--agent-service-account=konnectivity-agent",
+            "--kubeconfig=/etc/kubernetes/konnectivity-server.conf",
+            "--authentication-audience=system:konnectivity-server"
+            ]
+    livenessProbe:
+      httpGet:
+        scheme: HTTP
+        host: 127.0.0.1
+        port: 8134
+        path: /healthz
+      initialDelaySeconds: 30
+      timeoutSeconds: 60
+    ports:
+    - name: agentport
+      containerPort: 8132
+      hostPort: 8132
+    - name: adminport
+      containerPort: 8133
+      hostPort: 8133
+    - name: healthport
+      containerPort: 8134
+      hostPort: 8134
+    volumeMounts:
+    - name: k8s-certs
+      mountPath: /etc/kubernetes/pki
+      readOnly: true
+    - name: kubeconfig
+      mountPath: /etc/kubernetes/konnectivity-server.conf
+      readOnly: true
+    - name: konnectivity-uds
+      mountPath: /etc/kubernetes/konnectivity-server
+      readOnly: false
+  volumes:
+  - name: k8s-certs
+    hostPath:
+      path: /etc/kubernetes/pki
+  - name: kubeconfig
+    hostPath:
+      path: /etc/kubernetes/konnectivity-server.conf
+      type: FileOrCreate
+  - name: konnectivity-uds
+    hostPath:
+      path: /etc/kubernetes/konnectivity-server
+      type: DirectoryOrCreate