Configure pod resource request for k8s etcd pod - kubernetes

Question

When running k8s 1.18 alongside with a default “on cluster” etcd pod deployment, what is the way to assign a resource (CPU/memory) request, or influence the pod spec for the etcd container?
The default configuration provides no resource requests or limits.
Namespace Name CPU Requests CPU Limits Memory Requests Memory Limits AGE
--------- ---- ------------ ---------- --------------- ------------- ---
kube-system etcd-172-25-87-82-hybrid.com 0 (0%) 0 (0%) 0 (0%) 0 (0%) 77m
I’m aware of how one can pass extra args to etcd via kubeadm extraArgs config but these do not cover the etcd pod resources.
etcd:
local:
extraArgs:
heartbeat-interval: "1000"
election-timeout: "5000"
The question can be extended to the other resources in the kube-system namespace eg coredns, etc.

Answer 1

After init cluster, you can find generated /etc/kubernetes/manifests/etcd.yaml. Tried to edit it? The kubelet should pick the changes and restart the etcd instance.
root#kube-1:~# cat /etc/kubernetes/manifests/etcd.yaml
apiVersion: v1
kind: Pod
metadata:
annotations:
kubeadm.kubernetes.io/etcd.advertise-client-urls: https://10.154.0.33:2379
creationTimestamp: null
labels:
component: etcd
tier: control-plane
name: etcd
namespace: kube-system
spec:
containers:
- command:
- etcd
- --advertise-client-urls=https://10.154.0.33:2379
- --cert-file=/etc/kubernetes/pki/etcd/server.crt
- --client-cert-auth=true
- --data-dir=/var/lib/etcd
- --initial-advertise-peer-urls=https://10.154.0.33:2380
- --initial-cluster=kube-1=https://10.154.0.33:2380
- --key-file=/etc/kubernetes/pki/etcd/server.key
- --listen-client-urls=https://127.0.0.1:2379,https://10.154.0.33:2379
- --listen-metrics-urls=http://127.0.0.1:2381
- --listen-peer-urls=https://10.154.0.33:2380
- --name=kube-1
- --peer-cert-file=/etc/kubernetes/pki/etcd/peer.crt
- --peer-client-cert-auth=true
- --peer-key-file=/etc/kubernetes/pki/etcd/peer.key
- --peer-trusted-ca-file=/etc/kubernetes/pki/etcd/ca.crt
- --snapshot-count=10000
- --trusted-ca-file=/etc/kubernetes/pki/etcd/ca.crt
image: k8s.gcr.io/etcd:3.4.13-0
imagePullPolicy: IfNotPresent
livenessProbe:
failureThreshold: 8
httpGet:
host: 127.0.0.1
path: /health
port: 2381
scheme: HTTP
initialDelaySeconds: 10
periodSeconds: 10
timeoutSeconds: 15
name: etcd
resources: {}
startupProbe:
failureThreshold: 24
httpGet:
host: 127.0.0.1
path: /health
port: 2381
scheme: HTTP
initialDelaySeconds: 10
periodSeconds: 10
timeoutSeconds: 15
volumeMounts:
- mountPath: /var/lib/etcd
name: etcd-data
- mountPath: /etc/kubernetes/pki/etcd
name: etcd-certs
hostNetwork: true
priorityClassName: system-node-critical
volumes:
- hostPath:
path: /etc/kubernetes/pki/etcd
type: DirectoryOrCreate
name: etcd-certs
- hostPath:
path: /var/lib/etcd
type: DirectoryOrCreate
name: etcd-data
status: {}