k8s基于etcd的CoreDNS动态域名解析

土小帽

下载coredns yaml部署脚本
注意：如果已经部署coredns可忽略[ol]

wget https://github.com/coredns/deployment/raw/master/kubernetes/coredns.yaml.sed

wget https://github.com/coredns/deployment/raw/master/kubernetes/deploy.sh

chmod +x deploy.sh[/ol]复制代码
重新打coredns镜像
想将dns记录存在etcd中，如果内部https，etcd必须打证书，应此coredns必须带证书，将k8s相关证书打入coredns[ol]

mkdir /root/coredns

docker pull coredns/coredns:1.3.1

cp /etc/kubernetes/ssl/kubernetes .

cp /etc/kubernetes/ssl/k8s-root-ca.pem .[/ol]复制代码
Dockerfile[ol]

FROM coredns/coredns:1.3.1

ADD ./*.pem /[/ol]复制代码
Makefile
[ol]

VERSION=1.3.1-etcd

REGISTRY=hub.linuxeye.com

NAME=coredns

build-image:

        docker build -f Dockerfile -t $(REGISTRY)/library/$(NAME):$(VERSION) .

        docker push $(REGISTRY)/library/$(NAME):$(VERSION)[/ol]复制代码
build、推送镜像[ol]

make build-image[/ol]复制代码
替换image地址
vi coredns.yaml.sed

修改image镜像：hub.linuxeye.com/library/coredns:1.3.1-etcd

如果之前已经部署了coredns，修改coredns yaml镜像地址

kube-dns替换为coredns
注意：如果已经部署coredns可忽略

在k8s master节点执行，其中：172.22.0.2为 dns server ip[ol]

./deploy.sh -i 172.22.0.2 | kubectl apply -f -[/ol]复制代码
etcd存入hosts记录
注意：如果coredns是1.2.0以前版本，使用的是etcdv2 API版本，1.2.0及之后版本，使用etcdv3 API版本etcd V2:
[ol]

#设置key

etcdctl --ca-file=/etc/kubernetes/ssl/k8s-root-ca.pem --cert-file=/etc/kubernetes/ssl/kubernetes.pem --key-file=/etc/kubernetes/ssl/kubernetes-key.pem set /mydomain/kafka11 '{"Host":"10.50.1.11"}'

etcdctl --ca-file=/etc/kubernetes/ssl/k8s-root-ca.pem --cert-file=/etc/kubernetes/ssl/kubernetes.pem --key-file=/etc/kubernetes/ssl/kubernetes-key.pem set /mydomain/kafka12 '{"Host":"10.50.1.12"}'

etcdctl --ca-file=/etc/kubernetes/ssl/k8s-root-ca.pem --cert-file=/etc/kubernetes/ssl/kubernetes.pem --key-file=/etc/kubernetes/ssl/kubernetes-key.pem set /mydomain/kafka13 '{"Host":"10.50.1.13"}'

#验证获取key

etcdctl --ca-file=/etc/kubernetes/ssl/k8s-root-ca.pem --cert-file=/etc/kubernetes/ssl/kubernetes.pem --key-file=/etc/kubernetes/ssl/kubernetes-key.pem set /mydomain/kafka11

etcdctl --ca-file=/etc/kubernetes/ssl/k8s-root-ca.pem --cert-file=/etc/kubernetes/ssl/kubernetes.pem --key-file=/etc/kubernetes/ssl/kubernetes-key.pem set /mydomain/kafka12

etcdctl --ca-file=/etc/kubernetes/ssl/k8s-root-ca.pem --cert-file=/etc/kubernetes/ssl/kubernetes.pem --key-file=/etc/kubernetes/ssl/kubernetes-key.pem set /mydomain/kafka13[/ol]复制代码
etcd V3[ol]

#设置key

ETCDCTL_API=3 etcdctl --ca-file=/etc/kubernetes/ssl/k8s-root-ca.pem --cert-file=/etc/kubernetes/ssl/kubernetes.pem --key-file=/etc/kubernetes/ssl/kubernetes-key.pem put /mydomain/kafka11 '{"Host":"10.50.1.11"}'

ETCDCTL_API=3 etcdctl --ca-file=/etc/kubernetes/ssl/k8s-root-ca.pem --cert-file=/etc/kubernetes/ssl/kubernetes.pem --key-file=/etc/kubernetes/ssl/kubernetes-key.pem put /mydomain/kafka12 '{"Host":"10.50.1.12"}'

ETCDCTL_API=3 etcdctl --ca-file=/etc/kubernetes/ssl/k8s-root-ca.pem --cert-file=/etc/kubernetes/ssl/kubernetes.pem --key-file=/etc/kubernetes/ssl/kubernetes-key.pem put /mydomain/kafka13 '{"Host":"10.50.1.13"}'

#验证获取key

ETCDCTL_API=3 etcdctl --ca-file=/etc/kubernetes/ssl/k8s-root-ca.pem --cert-file=/etc/kubernetes/ssl/kubernetes.pem --key-file=/etc/kubernetes/ssl/kubernetes-key.pem set /mydomain/kafka11

ETCDCTL_API=3 etcdctl --ca-file=/etc/kubernetes/ssl/k8s-root-ca.pem --cert-file=/etc/kubernetes/ssl/kubernetes.pem --key-file=/etc/kubernetes/ssl/kubernetes-key.pem set /mydomain/kafka12

ETCDCTL_API=3 etcdctl --ca-file=/etc/kubernetes/ssl/k8s-root-ca.pem --cert-file=/etc/kubernetes/ssl/kubernetes.pem --key-file=/etc/kubernetes/ssl/kubernetes-key.pem set /mydomain/kafka13[/ol]复制代码
修改配置字典
命名空间kube-system coredns：[ol]

.:53 {

    errors

    health

    kubernetes cluster.local in-addr.arpa ip6.arpa {

      pods insecure

      upstream

      fallthrough in-addr.arpa ip6.arpa

    }

    prometheus :9153

    cache 30

    reload

    proxy . /etc/resolv.conf {

      except kafka11 kafka12 kafka13

    }

    etcd kafka11 kafka12 kafka13 {

      stubzones

      path /mydomain

      endpoint https://10.1.1.6:2379 https://10.1.1.7:2379 https://10.1.1.8:2379

      tls /kubernetes.pem /kubernetes-key.pem /k8s-root-ca.pem

    }

}

[/ol]复制代码