kubernetes 之dns 服务发现

1、在每个节点上面导入如下镜像

[root@node1 DNS]# ll
total 59816
-rw-r--r--. 1 root root 8603136 Nov 25 18:13 exechealthz-amd64.tar.gz
-rw-r--r--. 1 root root 47218176 Nov 25 18:13 kubedns-amd64.tar.gz
-rw-r--r--. 1 root root 5424640 Nov 25 18:13 kube-dnsmasq-amd64.tar.gz

准备好如下文件

[root@manager ~]# cat kubedns-deployment.yaml
# Copyright  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.*
# Should keep target in cluster/addons/dns-horizontal-autoscaler/dns-horizontal-autoscaler.yaml
# in sync with this file.

# Warning: This is a file generated from the base underscore template file: skydns-rc.yaml.base

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: kube-dns
  namespace: kube-system
  labels:
    k8s-app: kube-dns
    kubernetes.io/cluster-service: "true"
spec:
  replicas:
  # replicas: not specified here:
  # . In order to make Addon Manager do not reconcile this replicas parameter.
  # . Default is .
  # . Will be tuned in real time if DNS horizontal auto-scaling is turned on.
  strategy:
    rollingUpdate:
      maxSurge: %
      maxUnavailable:
  selector:
    matchLabels:
      k8s-app: kube-dns
  template:
    metadata:
      labels:
        k8s-app: kube-dns
      annotations:
        scheduler.alpha.kubernetes.io/critical-pod: ''
        scheduler.alpha.kubernetes.io/tolerations: '[{"key":"CriticalAddonsOnly", "operator":"Exists"}]'
    spec:
      containers:
      - name: kubedns
        image: hub.c..com/allan1991/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:
            scheme: HTTP
          initialDelaySeconds:
          timeoutSeconds:
          successThreshold:
          failureThreshold:
        readinessProbe:
          httpGet:
            path: /readiness
            port:
            scheme: HTTP
          # we poll on pod startup for the Kubernetes master service and
          # only setup the /readiness HTTP server once that's available.
          initialDelaySeconds:
          timeoutSeconds:
        args:
        - --kube-master-url=http://192.168.10.220:8080   #修改成自己的ip
        - --domain=cluster.local.
        - --dns-port=
        - --config-map=kube-dns
        # This should be set to v= only after the new image (cut from 1.5) has
        # been released, otherwise we will flood the logs.
        - --v=
        # {{ pillar['federations_domain_map'] }}
        env:
        - name: PROMETHEUS_PORT
          value: ""
        ports:
        - containerPort:
          name: dns-local
          protocol: UDP
        - containerPort:
          name: dns-tcp-local
          protocol: TCP
        - containerPort:
          name: metrics
          protocol: TCP
      - name: dnsmasq
        image: hub.c..com/allan1991/kube-dnsmasq-amd64:1.4
        livenessProbe:
          httpGet:
            path: /healthz-dnsmasq
            port:
            scheme: HTTP
          initialDelaySeconds:
          timeoutSeconds:
          successThreshold:
          failureThreshold:
        args:
        - --cache-size=
        - --no-resolv
        - --server=127.0.0.1#
        - --log-facility=-
        ports:
        - containerPort:
          name: dns
          protocol: UDP
        - containerPort:
          name: dns-tcp
          protocol: TCP
        # see: https://github.com/kubernetes/kubernetes/issues/29055 for details
        resources:
          requests:
            cpu: 150m
            memory: 10Mi
      # - name: dnsmasq-metrics
      #   image: gcr.io/google_containers/dnsmasq-metrics-amd64:1.0
      #   livenessProbe:
      #     httpGet:
      #       path: /metrics
      #       port:
      #       scheme: HTTP
      #     initialDelaySeconds:
      #     timeoutSeconds:
      #     successThreshold:
      #     failureThreshold:
      #   args:
      #   - --v=
      #   - --logtostderr
      #   ports:
      #   - containerPort:
      #     name: metrics
      #     protocol: TCP
      #   resources:
      #     requests:
      #       memory: 10Mi
      - name: healthz
        image: hub.c..com/allan1991/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 #.
            # 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: >/dev/null
        - --url=/healthz-kubedns
        - --port=
        - --quiet
        ports:
        - containerPort:
          protocol: TCP
      dnsPolicy: Default  # Don't use cluster DNS.

[root@manager ~]# cat kubedns-svc.yaml
# Copyright  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.

# This file should be kept in sync with cluster/images/hyperkube/dns-svc.yaml

# 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: 10.10.10.2
  ports:
  - name: dns
    port:
    protocol: UDP
  - name: dns-tcp
    port:
    protocol: TCP

检查结果

[root@manager ~]# kubectl create -f kubedns-svc.yaml
service "kube-dns" created
[root@manager ~]#
[root@manager ~]# kubectl create -f kubedns-deployment.yaml
deployment "kube-dns" created
[root@manager ~]#
[root@manager ~]# kubectl get pods --namespace=kube-system -l k8s-app=kube-dns
NAME                       READY     STATUS    RESTARTS   AGE
kube-dns-56d46f58f-6hhsl   /       Running             14s
kube-dns-56d46f58f-lnr86   /       Running             14s
kube-dns-56d46f58f-nbbxp   /       Running             14s
[root@manager ~]#
[root@manager ~]# kubectl get pods --namespace=kube-system -l k8s-app=kube-dns -o wide
NAME                       READY     STATUS    RESTARTS   AGE       IP          NODE
kube-dns-56d46f58f-6hhsl   /       Running             26s       10.0.71.4   192.168.10.222
kube-dns-56d46f58f-lnr86   /       Running             26s       10.0.91.4   192.168.10.221
kube-dns-56d46f58f-nbbxp   /       Running             26s       10.0.91.5   192.168.10.221

验证结果