From c73b5fc6751cbc996eeae96304d16afe63839852 Mon Sep 17 00:00:00 2001
From: Stefan Reimer <stefan@zero-downtime.net>
Date: Tue, 1 Sep 2020 14:18:02 +0100
Subject: [PATCH] Merge docs

---
 Quickstart.md => docs/Quickstart.md |  0
 docs/api-server.md                  | 15 +++++++++++++++
 docs/cluster.md                     |  9 +++++++++
 docs/kubectl.md                     | 21 +++++++++++++++++++++
 docs/worker.md                      | 15 +++++++++++++++
 5 files changed, 60 insertions(+)
 rename Quickstart.md => docs/Quickstart.md (100%)
 create mode 100644 docs/api-server.md
 create mode 100644 docs/cluster.md
 create mode 100644 docs/kubectl.md
 create mode 100644 docs/worker.md

diff --git a/Quickstart.md b/docs/Quickstart.md
similarity index 100%
rename from Quickstart.md
rename to docs/Quickstart.md
diff --git a/docs/api-server.md b/docs/api-server.md
new file mode 100644
index 0000000..ca66fa6
--- /dev/null
+++ b/docs/api-server.md
@@ -0,0 +1,15 @@
+# api-server OAuth configuration
+
+## Update Api-server config
+Add the following extraArgs to the ClusterConfiguration configMap in the kube-system namespace:
+`kubectl edit -n kube-system cm kubeadm-config`
+
+```
+        oidc-issuer-url: "https://accounts.google.com"
+        oidc-client-id: "<CLIENT_ID from Google>"
+        oidc-username-claim: "email"
+        oidc-groups-claim: "groups"
+```
+
+## Resources
+- https://kubernetes.io/docs/reference/access-authn-authz/authentication/
diff --git a/docs/cluster.md b/docs/cluster.md
new file mode 100644
index 0000000..0f97551
--- /dev/null
+++ b/docs/cluster.md
@@ -0,0 +1,9 @@
+# Cluster Operations
+
+## Clean up
+### Delete evicted pods across all namespaces
+
+`kubectl get pods --all-namespaces -o json | jq '.items[] | select(.status.reason!=null) | select(.status.reason | contains("Evicted")) | "kubectl delete pods \(.metadata.name) -n \(.metadata.namespace)"' | xargs -n 1 bash -c
+`
+### Cleanup old replicasets
+`kubectl get rs --all-namespaces | awk {' if ($3 == 0 && $4 == 0) system("kubectl delete rs "$2" --namespace="$1)'}`
diff --git a/docs/kubectl.md b/docs/kubectl.md
new file mode 100644
index 0000000..fa8283e
--- /dev/null
+++ b/docs/kubectl.md
@@ -0,0 +1,21 @@
+# kubectl
+kubectl is the basic cmdline tool to interact with any kubernetes cluster via the kube-api server.
+
+## Plugins
+As there are various very useful plugins for kubectl the first thing should be to install *krew* the plugin manager.  
+See: https://github.com/kubernetes-sigs/krew for details
+
+List of awesome plugins: https://github.com/ishantanu/awesome-kubectl-plugins
+
+### kubelogin
+To login / authenticate against an openID provider like Google install the kubelogin plugin.
+See: https://github.com/int128/kubelogin
+
+Make sure to adjust your kubeconfig files accordingly !
+
+### kauthproxy
+Easiest way to access the Kubernetes dashboard, if installed in the targeted cluster, is to use the kauthproxy plugin.
+See: https://github.com/int128/kauthproxy  
+Once installed simply execute:  
+`kubectl auth-proxy -n kubernetes-dashboard https://kubernetes-dashboard.svc`  
+and access the dashboard via the automatically opened browser window.
diff --git a/docs/worker.md b/docs/worker.md
new file mode 100644
index 0000000..0c4a767
--- /dev/null
+++ b/docs/worker.md
@@ -0,0 +1,15 @@
+# Operational guide for worker nodes
+
+## Replace worker node
+In order to change the instance type or in genernal replace worker nodes do:
+
+* (optional) Update the launch configuration of the worker group
+
+* Make sure there is enough capacity in the cluster to handle all pods being evicted for the node
+
+* `kubectl drain --ignore-daemonsets node_name`  
+will evict all pods except DaemonSets. In case there are pods with local storage review each affected pod. After being sure no important data will be lost add `--delete-local-data` to the original command above and try again.
+
+* Terminate instance matching *node_name*
+
+The new instance should take over the previous node_name assuming only node is being replaced at a time and automatically join and replace the previous node.