原文出处：https://blog.csdn.net/weixin_34018202/article/details/86828299
简单示例
$ cat deploy.sh
export NAMENODE_HOST=${NAMENODE_HOST:-`hostname -I|awk '{print $1}'`}
export KUBE_CLUSTER_DNS_IP=${KUBE_CLUSTER_DNS_IP:-'10.96.0.10'}
export K8S_CLUSTER_DOMAIN=${K8S_CLUSTER_DOMAIN:-'cluster.k8s.local'}
export DOCKER_REGISTRY=${DOCKER_REGISTRY:-'10.190.144.32:5000'}
envsubst < /data/kube_dns.yaml
cat /data/kube_dns.yaml
$ cat /data/kube_dns.yaml
#!/bin/bash
echo ${NAMENODE_HOST}
echo ${KUBE_CLUSTER_DNS_IP}
echo ${K8S_CLUSTER_DOMAIN}
echo ${DOCKER_REGISTRY}
执行结果
]# bash deploy.sh
#!/bin/bash
echo 192.168.19.139
echo 10.96.0.10
echo cluster.k8s.local
echo 10.190.144.32:5000
#!/bin/bash
echo ${NAMENODE_HOST}
echo ${KUBE_CLUSTER_DNS_IP}
echo ${K8S_CLUSTER_DOMAIN}
echo ${DOCKER_REGISTRY}
实战演练：
$ cat deploy.sh
export NAMENODE_HOST=${NAMENODE_HOST:-`hostname -I|awk '{print $1}'`}
export KUBE_CLUSTER_DNS_IP=${KUBE_CLUSTER_DNS_IP:-'10.96.0.10'}
export K8S_CLUSTER_DOMAIN=${K8S_CLUSTER_DOMAIN:-'cluster.k8s.local'}
export DOCKER_REGISTRY=${DOCKER_REGISTRY:-'10.190.144.32:5000'}
#envsubst < /data/kube_dns.yaml | kubectl create -f -
envsubst < /data/kube_dns.yaml
cat /data/kube_dns.yaml
部分脚本内容
$ cat /data/kube_dns.yaml
kind: Service
metadata:
spec:
selector:
k8s-app: kube-dns
clusterIP: $KUBE_CLUSTER_DNS_IP
spec:
containers:
- name: kubedns
image: ${DOCKER_REGISTRY}/k8s-dns-kube-dns-amd64:1.14.7
readinessProbe:
httpGet:
path: /readiness
port: 8081
scheme: HTTP
initialDelaySeconds: 3
timeoutSeconds: 5
args:
- --domain=${K8S_CLUSTER_DOMAIN}.
env:
- name: AIDU_KUBERNETES_LOG_ENDPOINT
value: ${NAMENODE_HOST}:8070
以上俩个脚本，deploy.sh脚本中定义了一些变量，需要替换kube_dns.yaml文件中写好的变量，然后执行。
执行结果
]# bash -xv deploy.sh
export NAMENODE_HOST=${NAMENODE_HOST:-`hostname -I|awk '{print $1}'`}
hostname -I|awk '{print $1}'
++ awk '{print $1}'
++ hostname -I
+ export NAMENODE_HOST=192.168.19.139
+ NAMENODE_HOST=192.168.19.139
export KUBE_CLUSTER_DNS_IP=${KUBE_CLUSTER_DNS_IP:-'10.96.0.10'}
+ export KUBE_CLUSTER_DNS_IP=10.96.0.10
+ KUBE_CLUSTER_DNS_IP=10.96.0.10
export K8S_CLUSTER_DOMAIN=${K8S_CLUSTER_DOMAIN:-'cluster.k8s.local'}
+ export K8S_CLUSTER_DOMAIN=cluster.k8s.local
+ K8S_CLUSTER_DOMAIN=cluster.k8s.local
export DOCKER_REGISTRY=${DOCKER_REGISTRY:-'10.190.144.32:5000'}
+ export DOCKER_REGISTRY=10.190.144.32:5000
+ DOCKER_REGISTRY=10.190.144.32:5000
#envsubst < /data/kube_dns.yaml | kubectl create -f -
envsubst < /data/kube_dns.yaml
+ envsubst
apiVersion: v1
kind: Service
metadata:
spec:
selector:
k8s-app: kube-dns
clusterIP: 10.96.0.10
spec:
containers:
- name: kubedns
image: 10.190.144.32:5000/k8s-dns-kube-dns-amd64:1.14.7
readinessProbe:
httpGet:
path: /readiness
port: 8081
scheme: HTTP
initialDelaySeconds: 3
timeoutSeconds: 5
args:
- --domain=cluster.k8s.local.
env:
- name: AIDU_KUBERNETES_LOG_ENDPOINT
value: 192.168.19.139:8070
cat /data/kube_dns.yaml
+ cat /data/kube_dns.yaml
apiVersion: v1
kind: Service
metadata:
spec:
selector:
k8s-app: kube-dns
clusterIP: $KUBE_CLUSTER_DNS_IP
spec:
containers:
- name: kubedns
image: ${DOCKER_REGISTRY}/k8s-dns-kube-dns-amd64:1.14.7
readinessProbe:
httpGet:
path: /readiness
port: 8081
scheme: HTTP
initialDelaySeconds: 3
timeoutSeconds: 5
args:
- --domain=${K8S_CLUSTER_DOMAIN}.
env:
- name: AIDU_KUBERNETES_LOG_ENDPOINT
value: ${NAMENODE_HOST}:8070