kubernetes-training

Definition

• Distributed key-value storage

  Install

  

• etcd is typically set up to listen on port 2379

[!Source] https://www.udemy.com/course/certified-kubernetes-administrator-with-practice-tests/learn/lecture/19537454#overview

•  You must also specify path to certificate files so that ETCDCTL can authenticate to the ETCD API Server. The certificate files are available in the etcd-master at the following path :

1. --cacert /etc/kubernetes/pki/etcd/ca.crt
2. --cert /etc/kubernetes/pki/etcd/server.crt
3. --key /etc/kubernetes/pki/etcd/server.key

• Example:

  kubectl exec etcd-master -n kube-system -- sh -c "ETCDCTL_API=3 etcdctl get / --prefix --keys-only --limit=10 --cacert /etc/kubernetes/pki/etcd/ca.crt --cert /etc/kubernetes/pki/etcd/server.crt --key /etc/kubernetes/pki/etcd/server.key"
  

ETCD’s manifest specific

--listen-peer-urls=https://172.30.1.2:2380

• List of URLs to listen on for peer traffic.
• Default: http://localhost:2380
• env variable: ETCD_LISTEN_PEER_URLS

  --listen-client-urls=https://127.0.0.1:2379,https://172.30.1.2:2379
  

• List of URLs to listen on for client traffic. This flag tells the etcd to accept incoming requests from the clients on the specified scheme
• Default: “http://localhost:2379”
• env variable: ETCD_LISTEN_CLIENT_URLS
• example: “http://10.0.0.1:2379”
• invalid example: “http://example.com:2379” (domain name is invalid for binding)

  [!Important] ** kube-api talks to etcd using listen-client-urls**

  --listen-metrics-urls=http://127.0.0.1:2381
  

• useful for healthcheck, also respond to /health endpoint.
• the /livez endpoint reflects whether the process is alive or if it needs a restart.
• the /readyz endpoint reflects whether the process is ready to serve traffic.