From 268973b85fe0baeab3573a53b2bccba3ca3768ff Mon Sep 17 00:00:00 2001
From: Vico Chu <vico24826@gmail.com>
Date: Wed, 1 Feb 2023 20:39:19 +0800
Subject: [PATCH] Docs: add k8s network configurations documentations

---
 docs/commands/kk-delete-cluster.md |  4 ++--
 docs/commands/kk-delete-node.md    |  2 +-
 docs/network-configurations.md     | 25 +++++++++++++++++++++++++
 3 files changed, 28 insertions(+), 3 deletions(-)
 create mode 100644 docs/network-configurations.md

diff --git a/docs/commands/kk-delete-cluster.md b/docs/commands/kk-delete-cluster.md
index fa705378..6370ba3e 100644
--- a/docs/commands/kk-delete-cluster.md
+++ b/docs/commands/kk-delete-cluster.md
@@ -2,7 +2,7 @@
 **kk delete cluster**: Delete a cluster.
 
 # DESCRIPTION
-Delete a cluster. This command will use the `kubeadm reset` to reset all the nodes. Then, reset network policy, stop `etcd`, remove cluster directory and uninstall Kubernetes certs-auto-renew script.
+Delete a cluster. This command will use the `kubeadm reset` to reset all the nodes. Then, reset network policy, stop `etcd`, remove cluster directory, uninstall Kubernetes certs-auto-renew script and remove internal Loadbalancer module. And [network configurations](../network-configurations.md) on each node will be cleaned up.
 
 # OPTIONS
 
@@ -24,7 +24,7 @@ Delete a cluster from a specified configuration file.
 ```
 $ kk delete cluster -f config-example.yaml
 ```
-Delete a cluster included CRI related files and directories from a specified configuraion file.
+Delete a cluster included CRI related files and directories from a specified configuration file.
 ```
 $ kk delete cluster -f config-example.yaml --all
 $ kk delete cluster -f config-example.yaml -A
diff --git a/docs/commands/kk-delete-node.md b/docs/commands/kk-delete-node.md
index c6494343..d0835c0e 100644
--- a/docs/commands/kk-delete-node.md
+++ b/docs/commands/kk-delete-node.md
@@ -2,7 +2,7 @@
 **kk delete node**: Delete a node.
 
 # DESCRIPTION
-Delete a node. This command will use the `kubectl drain` to safely evict all pods, and then use `kubectl delete node`  to delete the specified node.
+Delete and cleanup a node. This command will use the `kubectl drain` to safely evict all pods, then use `kubectl delete node` to delete the specified node. And [network configurations](../network-configurations.md) on the node will be cleaned up.
 
 # OPTIONS
 
diff --git a/docs/network-configurations.md b/docs/network-configurations.md
new file mode 100644
index 00000000..f47c3d22
--- /dev/null
+++ b/docs/network-configurations.md
@@ -0,0 +1,25 @@
+### Network Configurations
+
+#### IPVS
+
+If your cluster's kubeProxy mode is `ipvs` which is default value in `kk`, kubernetes will add some ipvs records on each node. You can use `ipvsadm` command to get more information.
+
+#### Iptables
+
+If your cluster's kubeProxy mode is `iptables`, kubernetes will add some iptables records on each node. You can use `iptables` command to get more information.
+
+#### Virtual Device
+
+Most of CNI Plugins will create some virtual devices on each node, such as `cni0`. You can use `ip link` command to inspect them in details.
+
+As for `flannel`, virtual devices named with `flannel` prefix will be created.
+As for `calico`, virtual devices named in `cali[a-f0-9]*` regexp format will be created.
+As for `cilium`, virtual devices named with `cilium_` prefix will be created.
+
+If your cluster's kubeProxy mode is `ipvs`, additional virtual device `kube-ipvs0` will be created.
+
+If your cluster enables `nodelocaldns` feature for DNS caching purpose, additional virtual device `nodelocaldns` will be created.
+
+#### Network Namespace
+
+CNI plugins may create some network namespaces named with `cni-` prefix depends on which CNI plugin you choose to use. You can use `ip netns show 2>/dev/null | grep cni-` command to get CNI network namespace list.