DNS部署
基于上一篇文章从零开始搭建基于calico的kubenetes，已经完成了kubernetes的部署。但未部署DNS。本章节将介绍DNS部署。
配置文件准备
skydns-rc.yaml 注意此文件与kubernetes官方提供的模板相比，在此mount了从节点的配置文件/etc/kubernetes/worker-kubeconfig.yaml,原因在于DNS部署有时候会出现很多未知的错误，如：10.100.0.1:443链接被拒绝、或者证书加载错误等:
# 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.
# TODO - At some point, we need to rename all skydns-*.yaml.* files to kubedns-*.yaml.*
# Warning: This is a file generated from the base underscore template file: skydns-rc.yaml.base
apiVersion: v1
kind: ReplicationController
metadata:
name: kube-dns-v20
namespace: kube-system
labels:
k8s-app: kube-dns
version: v20
kubernetes.io/cluster-service: "true"
spec:
replicas: 1
selector:
k8s-app: kube-dns
version: v20
template:
metadata:
labels:
k8s-app: kube-dns
version: v20
annotations:
scheduler.alpha.kubernetes.io/critical-pod: ''
scheduler.alpha.kubernetes.io/tolerations: '[{"key":"CriticalAddonsOnly", "operator":"Exists"}]'
spec:
containers:
- name: kubedns
image: shenshouer/kubedns-amd64:1.9
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: /healthz-kubedns
port: 8080
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:
# command = "/kube-dns"
- --domain=cluster.local.
- --dns-port=10053
# - --kube-master-url=https://172.18.8.101
- --kubecfg-file=/etc/kubernetes/worker-kubeconfig.yaml
- --federations=myfederation=federation.test
ports:
- containerPort: 10053
name: dns-local
protocol: UDP
- containerPort: 10053
name: dns-tcp-local
protocol: TCP
volumeMounts:
- mountPath: /etc/ssl/certs
name: "ssl-certs"
- mountPath: /etc/kubernetes/worker-kubeconfig.yaml
name: "kubeconfig"
readOnly: true
- mountPath: /etc/kubernetes/ssl
name: "etc-kube-ssl"
readOnly: true
- name: dnsmasq
image: shenshouer/kube-dnsmasq-amd64:1.4
livenessProbe:
httpGet:
path: /healthz-dnsmasq
port: 8080
scheme: HTTP
initialDelaySeconds: 60
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 5
args:
- --cache-size=1000
- --no-resolv
- --server=127.0.0.1#10053
- --log-facility=-
ports:
- containerPort: 53
name: dns
protocol: UDP
- containerPort: 53
name: dns-tcp
protocol: TCP
- name: healthz
image: shenshouer/exechealthz-amd64:1.2
resources:
limits:
memory: 50Mi
requests:
cpu: 10m
# Note that this container shouldn't really need 50Mi of memory. The
# limits are set higher than expected pending investigation on #29688.
# The extra memory was stolen from the kubedns container to keep the
# net memory requested by the pod constant.
memory: 50Mi
args:
- --cmd=nslookup kubernetes.default.svc.cluster.local 127.0.0.1 >/dev/null
- --url=/healthz-dnsmasq
- --cmd=nslookup kubernetes.default.svc.cluster.local 127.0.0.1:10053 >/dev/null
- --url=/healthz-kubedns
- --port=8080
- --quiet
ports:
- containerPort: 8080
protocol: TCP
dnsPolicy: Default # Don't use cluster DNS.
volumes:
- name: "ssl-certs"
hostPath:
path: "/usr/share/ca-certificates"
- name: "kubeconfig"
hostPath:
path: "/etc/kubernetes/worker-kubeconfig.yaml"
- name: "etc-kube-ssl"
hostPath:
path: "/etc/kubernetes/ssl"
skydns-svc.yaml与官方模板相同:
# 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.
# TODO - At some point, we need to rename all skydns-*.yaml.* files to kubedns-*.yaml.*
# Warning: This is a file generated from the base underscore template file: skydns-svc.yaml.base
apiVersion: v1
kind: Service
metadata:
name: kube-dns
namespace: kube-system
labels:
k8s-app: kube-dns
kubernetes.io/cluster-service: "true"
kubernetes.io/name: "KubeDNS"
spec:
selector:
k8s-app: kube-dns
clusterIP: 172.30.0.10
ports:
- name: dns
port: 53
protocol: UDP
- name: dns-tcp
port: 53
protocol: TCP
http://blog.csdn.net/shenshouer/article/details/52946194?locationNum=2&fps=1
http://blog.csdn.net/shenshouer/article/details/53035948
https://github.com/kubernetes/kubernetes/tree/master/cluster/addons/dns