k8s部署-17-网络插件和dns解析服务配置_ip地址


经过前几篇的文章,我们通过二进制方式部署的k8s集群,差不多所有的组件都部署好了,接下来就差我们的网络插件和dns了,在这里我们的网络插件使用calico,dns解析使用coredns。

k8s部署-17-网络插件和dns解析服务配置_ip地址_02


网络插件安装

PS:该步骤只需要在node1上执行即可,即master节点执行。下面的地址是官网地址,感兴趣的可以看下介绍:

https://projectcalico.docs.tigera.io/getting-started/kubernetes/self-managed-onprem/onpremises


如果你的节点数量是50以下,选择以下命令下载:

[root@node1 ~]# curl https://projectcalico.docs.tigera.io/manifests/calico.yaml -O
[root@node1 ~]# ls calico.yaml
calico.yaml
[root@node1 ~]#


如果是50个节点以上,请执行如下命令下载:

[root@node1 ~]# curl https://projectcalico.docs.tigera.io/manifests/calico-typha.yaml -o calico.yaml
[root@node1 ~]# ls calico.yaml
calico.yaml
[root@node1 ~]#


修改IP自动发现:为啥要修改呢?因为如果当你的服务器上存在多个IP地址,或者说有很多虚拟网卡的时候,他有时候就会获取到错误的IP地址,所以要进行如下配置。

[root@node1 ~]# vim calico.yaml  # 有两个配置需要修改
# 修改前
- name: IP
value: "autodetect"

# 修改成
- name: IP
valueFrom:
fieldRef:
fieldPath: status.hostIP

# 修改前是被注释的状态
# - name: CALICO_IPV4POOL_CIDR
# value: "192.168.0.0/16"
# 修改成
- name: CALICO_IPV4POOL_CIDR
value: "10.200.0.0/16"
[root@node1 ~]#


让其生效:

[root@node1 ~]# kubectl apply -f calico.yaml


等几分钟之后,查看状态如下,如果status不是running,可能是镜像还没有下载完,再稍等几分钟就行了。

[root@node1 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
node2 Ready <none> 15h v1.20.2
node3 Ready <none> 15h v1.20.2
[root@node1 ~]#
[root@node1 ~]# kubectl get pod -n kube-system
NAME READY STATUS RESTARTS AGE
calico-kube-controllers-858c9597c8-6gzd5 1/1 Running 0 43m
calico-node-6k479 1/1 Running 0 43m
calico-node-bnbxx 1/1 Running 0 43m
nginx-proxy-node3 1/1 Running 1 15h
[root@node1 ~]#


DNS解析

设置nds的cluster-ip地址:

# 这个IP要和之前安装apiserver的时候配置中的一个哈
[root@node1 ~]# COREDNS_CLUSTER_IP=10.233.0.10


创建coredns.yaml的配置:

# 以下配置文件不需要修改任何信息
[root@node1 ~]# vim coredns.yaml
---
apiVersion: v1
kind: ConfigMap
metadata:
name: coredns
namespace: kube-system
labels:
addonmanager.kubernetes.io/mode: EnsureExists
data:
Corefile: |
.:53 {
errors
health {
lameduck 5s
}
ready
kubernetes cluster.local in-addr.arpa ip6.arpa {
pods insecure
fallthrough in-addr.arpa ip6.arpa
}
prometheus :9153
forward . /etc/resolv.conf {
prefer_udp
}
cache 30
loop
reload
loadbalance
}
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: coredns
namespace: kube-system
labels:
addonmanager.kubernetes.io/mode: Reconcile
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
labels:
kubernetes.io/bootstrapping: rbac-defaults
addonmanager.kubernetes.io/mode: Reconcile
name: system:coredns
rules:
- apiGroups:
- ""
resources:
- endpoints
- services
- pods
- namespaces
verbs:
- list
- watch
- apiGroups:
- ""
resources:
- nodes
verbs:
- get
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
annotations:
rbac.authorization.kubernetes.io/autoupdate: "true"
labels:
kubernetes.io/bootstrapping: rbac-defaults
addonmanager.kubernetes.io/mode: EnsureExists
name: system:coredns
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: system:coredns
subjects:
- kind: ServiceAccount
name: coredns
namespace: kube-system
---
apiVersion: v1
kind: Service
metadata:
name: coredns
namespace: kube-system
labels:
k8s-app: kube-dns
kubernetes.io/name: "coredns"
addonmanager.kubernetes.io/mode: Reconcile
annotations:
prometheus.io/port: "9153"
prometheus.io/scrape: "true"
spec:
selector:
k8s-app: kube-dns
clusterIP: ${COREDNS_CLUSTER_IP}
ports:
- name: dns
port: 53
protocol: UDP
- name: dns-tcp
port: 53
protocol: TCP
- name: metrics
port: 9153
protocol: TCP
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: "coredns"
namespace: kube-system
labels:
k8s-app: "kube-dns"
addonmanager.kubernetes.io/mode: Reconcile
kubernetes.io/name: "coredns"
spec:
replicas: 2
strategy:
type: RollingUpdate
rollingUpdate:
maxUnavailable: 0
maxSurge: 10%
selector:
matchLabels:
k8s-app: kube-dns
template:
metadata:
labels:
k8s-app: kube-dns
annotations:
seccomp.security.alpha.kubernetes.io/pod: 'runtime/default'
spec:
priorityClassName: system-cluster-critical
nodeSelector:
kubernetes.io/os: linux
serviceAccountName: coredns
tolerations:
- key: node-role.kubernetes.io/master
effect: NoSchedule
affinity:
podAntiAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- topologyKey: "kubernetes.io/hostname"
labelSelector:
matchLabels:
k8s-app: kube-dns
nodeAffinity:
preferredDuringSchedulingIgnoredDuringExecution:
- weight: 100
preference:
matchExpressions:
- key: node-role.kubernetes.io/master
operator: In
values:
- ""
containers:
- name: coredns
image: "docker.io/coredns/coredns:1.6.7"
imagePullPolicy: IfNotPresent
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
args: [ "-conf", "/etc/coredns/Corefile" ]
volumeMounts:
- name: config-volume
mountPath: /etc/coredns
ports:
- containerPort: 53
name: dns
protocol: UDP
- containerPort: 53
name: dns-tcp
protocol: TCP
- containerPort: 9153
name: metrics
protocol: TCP
securityContext:
allowPrivilegeEscalation: false
capabilities:
add:
- NET_BIND_SERVICE
drop:
- all
readOnlyRootFilesystem: true
livenessProbe:
httpGet:
path: /health
port: 8080
scheme: HTTP
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 10
readinessProbe:
httpGet:
path: /ready
port: 8181
scheme: HTTP
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 10
dnsPolicy: Default
volumes:
- name: config-volume
configMap:
name: coredns
items:
- key: Corefile
path: Corefile


[root@node1 ~]# sed -i "s/\${COREDNS_CLUSTER_IP}/${COREDNS_CLUSTER_IP}/g" coredns.yaml
[root@node1 ~]#


使其生效:

[root@node1 ~]# kubectl apply -f coredns.yaml


部署NodeLocal DNSCache:

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