k8s-安装文档-04-kube-dns插件安装-服务发现实现
2023-06-01 00:00:00
K8S
kube-dns
## 说明及参考
> https://github.com/kubernetes/kubernetes/tree/master/cluster/addons/dns
> https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/- 以下配置是基于官网提供的yaml文件简单修改而来。这种标准组件基本就是拿来就可以用的。
## kube-dns.yaml
[[email protected] kube-dns]# cat kube-dns.yml
# Copyright 2016 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# Should keep target in cluster/addons/dns-horizontal-autoscaler/dns-horizontal-autoscaler.yaml
# in sync with this file.
# __MACHINE_GENERATED_WARNING__
apiVersion: v1
kind: Service
metadata:
name: kube-dns
namespace: kube-system
labels:
k8s-app: kube-dns
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
kubernetes.io/name: "KubeDNS"
spec:
selector:
k8s-app: kube-dns
clusterIP: 10.254.0.2
ports:
- name: dns
port: 53
protocol: UDP
- name: dns-tcp
port: 53
protocol: TCP
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: kube-dns
namespace: kube-system
labels:
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
---
apiVersion: v1
kind: ConfigMap
metadata:
name: kube-dns
namespace: kube-system
labels:
addonmanager.kubernetes.io/mode: EnsureExists
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: kube-dns
namespace: kube-system
labels:
k8s-app: kube-dns
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
spec:
# replicas: not specified here:
# 1. In order to make Addon Manager do not reconcile this replicas parameter.
# 2. Default is 1.
# 3. Will be tuned in real time if DNS horizontal auto-scaling is turned on.
strategy:
rollingUpdate:
maxSurge: 10%
maxUnavailable: 0
selector:
matchLabels:
k8s-app: kube-dns
template:
metadata:
labels:
k8s-app: kube-dns
annotations:
scheduler.alpha.kubernetes.io/critical-pod: ''
spec:
tolerations:
- key: "CriticalAddonsOnly"
operator: "Exists"
volumes:
- name: kube-dns-config
configMap:
name: kube-dns
optional: true
containers:
- name: kubedns
image: 10.0.1.147/k8s/k8s-dns-kube-dns-amd64:1.14.7
resources:
# TODO: Set memory limits when we've profiled the container for large
# clusters, then set request = limit to keep this container in
# guaranteed class. Currently, this container falls into the
# "burstable" category so the kubelet doesn't backoff from restarting it.
limits:
memory: 170Mi
requests:
cpu: 100m
memory: 70Mi
livenessProbe:
httpGet:
path: /healthcheck/kubedns
port: 10054
scheme: HTTP
initialDelaySeconds: 60
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 5
readinessProbe:
httpGet:
path: /readiness
port: 8081
scheme: HTTP
# we poll on pod startup for the Kubernetes master service and
# only setup the /readiness HTTP server once that's available.
initialDelaySeconds: 3
timeoutSeconds: 5
args:
- --domain=cluster.local.
- --dns-port=10053
- --config-dir=/kube-dns-config
- --v=2
env:
- name: PROMETHEUS_PORT
value: "10055"
ports:
- containerPort: 10053
name: dns-local
protocol: UDP
- containerPort: 10053
name: dns-tcp-local
protocol: TCP
- containerPort: 10055
name: metrics
protocol: TCP
volumeMounts:
- name: kube-dns-config
mountPath: /kube-dns-config
- name: dnsmasq
image: 10.0.1.147/k8s/k8s-dns-dnsmasq-nanny-amd64:1.14.7
livenessProbe:
httpGet:
path: /healthcheck/dnsmasq
port: 10054
scheme: HTTP
initialDelaySeconds: 60
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 5
args:
- -v=2
- -logtostderr
- -configDir=/etc/k8s/dns/dnsmasq-nanny
- -restartDnsmasq=true
- --
- -k
- --cache-size=1000
- --no-negcache
- --log-facility=-
- --server=/cluster.local./127.0.0.1#10053
- --server=/in-addr.arpa/127.0.0.1#10053
- --server=/ip6.arpa/127.0.0.1#10053
ports:
- containerPort: 53
name: dns
protocol: UDP
- containerPort: 53
name: dns-tcp
protocol: TCP
# see: https://github.com/kubernetes/kubernetes/issues/29055 for details
resources:
requests:
cpu: 150m
memory: 20Mi
volumeMounts:
- name: kube-dns-config
mountPath: /etc/k8s/dns/dnsmasq-nanny
- name: sidecar
image: 10.0.1.147/k8s/k8s-dns-sidecar-amd64:1.14.7
livenessProbe:
httpGet:
path: /metrics
port: 10054
scheme: HTTP
initialDelaySeconds: 60
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 5
args:
- --v=2
- --logtostderr
- --probe=kubedns,127.0.0.1:10053,kubernetes.default.svc.cluster.local.,5,SRV
- --probe=dnsmasq,127.0.0.1:53,kubernetes.default.svc.cluster.local.,5,SRV
ports:
- containerPort: 10054
name: metrics
protocol: TCP
resources:
requests:
memory: 20Mi
cpu: 10m
dnsPolicy: Default # Don't use cluster DNS.
serviceAccountName: kube-dns## DNS 自动扩展配置
[[email protected] kube-dns]# cat dns-horizontal-autoscaler.yaml
# Copyright 2016 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
kind: ServiceAccount
apiVersion: v1
metadata:
name: kube-dns-autoscaler
namespace: kube-system
labels:
addonmanager.kubernetes.io/mode: Reconcile
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: system:kube-dns-autoscaler
labels:
addonmanager.kubernetes.io/mode: Reconcile
rules:
- apiGroups: [""]
resources: ["nodes"]
verbs: ["list"]
- apiGroups: [""]
resources: ["replicationcontrollers/scale"]
verbs: ["get", "update"]
- apiGroups: ["extensions"]
resources: ["deployments/scale", "replicasets/scale"]
verbs: ["get", "update"]
# Remove the configmaps rule once below issue is fixed:
# kubernetes-incubator/cluster-proportional-autoscaler#16
- apiGroups: [""]
resources: ["configmaps"]
verbs: ["get", "create"]
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: system:kube-dns-autoscaler
labels:
addonmanager.kubernetes.io/mode: Reconcile
subjects:
- kind: ServiceAccount
name: kube-dns-autoscaler
namespace: kube-system
roleRef:
kind: ClusterRole
name: system:kube-dns-autoscaler
apiGroup: rbac.authorization.k8s.io
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: kube-dns-autoscaler
namespace: kube-system
labels:
k8s-app: kube-dns-autoscaler
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
spec:
template:
metadata:
labels:
k8s-app: kube-dns-autoscaler
annotations:
scheduler.alpha.kubernetes.io/critical-pod: ''
spec:
containers:
- name: autoscaler
image: 10.0.1.147/k8s/cluster-proportional-autoscaler-amd64:1.1.2-r2
resources:
requests:
cpu: "20m"
memory: "10Mi"
command:
- /cluster-proportional-autoscaler
- --namespace=kube-system
- --configmap=kube-dns-autoscaler
# Should keep target in sync with cluster/addons/dns/kube-dns.yaml.base
- --target=Deployment/kube-dns
# When cluster is using large nodes(with more cores), "coresPerReplica" should dominate.
# If using small nodes, "nodesPerReplica" should dominate.
- --default-params={"linear":{"coresPerReplica":256,"nodesPerReplica":16,"preventSinglePointFailure":true}}
- --logtostderr=true
- --v=2
tolerations:
- key: "CriticalAddonsOnly"
operator: "Exists"
serviceAccountName: kube-dns-autoscaler
ps:
从 Kubernetes v1.12 开始，CoreDNS 是推荐的 DNS 服务器，取代了 kube-dns。 如果 你的集群原来使用 kube-dns，你可能部署的仍然是 kube-dns 而不是 CoreDNS。
k8s手册：
https://kubernetes.io/zh/docs/tasks/administer-cluster/dns-custom-nameservers/
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