kubernetes学习笔记

本文的环境介绍

[root@m-30-1 ~]# kubectl version
Client Version: version.Info{Major:"1", Minor:"10", GitVersion:"v1.10.2", GitCommit:"81753b10df112992bf51bbc2c2f85208aad78335", GitTreeState:"clean", BuildDate:"2018-04-27T09:22:21Z", GoVersion:"go1.9.3", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"10", GitVersion:"v1.10.2", GitCommit:"81753b10df112992bf51bbc2c2f85208aad78335", GitTreeState:"clean", BuildDate:"2018-04-27T09:10:24Z", GoVersion:"go1.9.3", Compiler:"gc", Platform:"linux/amd64"}
[root@m-30-1 ~]# rpm -qf /etc/issue
centos-release-7-4.1708.el7.centos.x86_64

kubernetes集群是通过kubeadm安装的

本文中很多内容都参考了净超大神的网站,大家可以多看看，O(∩_∩)O~
本文目录：
kubernetes 通过pod的mac地址找到对应的宿主机虚拟网卡
kubernetes替换默认的kube-dns为coredns
helm以daemonset方式部署ingress-nginx
glusterfs-restapi-heketi部署

kubernetes 通过pod的mac地址找到对应的宿主机虚拟网卡

创建一个 centos 镜像的 pod ，安装 iproute

kubectl -n wis run centos --image=centos --replicas=2 -- tail -f /dev/null
kubectl -n wis exec centos-7f55f898b4-7w69j -it -- bash
# 进入 pod
yum install -y iproute
# 查看 mac 地址
ip a
3: eth0@if30: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
    link/ether 0a:58:0a:f4:00:65 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 10.244.0.101/24 scope global eth0
       valid_lft forever preferred_lft forever

然后宿主机上执行下面的命令查看网桥的信息。

yum install -y bridge-utils
brctl show
brctl showmacs kube-bridge

还有就是直接从 pod 里面 ping 百度，然后宿主机上 ping pod ip 。通过 ip neigh 查看 mac 地址也能知道 pod 对应宿主机的虚拟网卡。通过 brctl showmacs kube-bridge 可以看到 pod 对应的 mac 地址和宿主机上对应的网卡其实是在同一个端口上，然后一个 local yes， 一个是 no 。

[root@node1 ~]# brctl showmacs kube-bridge|head -1;brctl showmacs kube-bridge| grep 21
port no	mac addr		is local?	ageing timer
 21	0a:58:0a:f4:00:62	no		   0.39
 21	ca:46:f0:00:ec:1d	yes		   0.00
 21	ca:46:f0:00:ec:1d	yes		   0.00

kubernetes替换默认的kube-dns为coredns

之所以是因为好多人说kube-dns太不好用了，而且我是用kubeadm安装的运行了一段时间，master节点的pod的DNS就用不了了，我就换了coredns就好了。

# 导出原来的deployment
kubectl get -n kube-system deployment kube-dns -o yaml > /tmp/kube-dns-deployment.yaml
# 然后就开始替换了
cd /opt
git clone https://github.com/coredns/deployment.git
cd /opt/coredns/deployment/kubernetes
./deploy.sh |kubectl apply -f -
kubectl delete --namespace=kube-system deployment kube-dns

helm以daemonset方式部署ingress-nginx

首先查看整体的变量然后修改对应的参数，具体如下

[root@m-30-1 deploy]# helm inspect values stable/nginx-ingress|egrep -v "^$" > value2.yaml
[root@m-30-1 deploy]# diff value.yaml value2.yaml
1d0
<
17c16
<   hostNetwork: true
---
>   hostNetwork: false
24c23
<     useHostPort: true
---
>     useHostPort: false
66c65
<   kind: DaemonSet
---
>   kind: Deployment
88,89c87
<   nodeSelector:
<     kubernetes.io/hostname: m-30-2
---
>   nodeSelector: {}
270c268,287

我们还是测试环境所以设置了nodeSelector。

glusterfs restapi heketi部署

主要是如果用普通用户启动并且ssh的executor需要设置"sudo": true。

[root@m-30-2 kubernetes]# cat /etc/heketi/heketi.json
{
  "_port_comment": "Heketi Server Port Number",
  "port": "8090",

  "_use_auth": "Enable JWT authorization. Please enable for deployment",
  "use_auth": false,

  "_jwt": "Private keys for access",
  "jwt": {
    "_admin": "Admin has access to all APIs",
    "admin": {
      "key": "My Secret"
    },
    "_user": "User only has access to /volumes endpoint",
    "user": {
      "key": "My Secret"
    }
  },

  "_glusterfs_comment": "GlusterFS Configuration",
  "glusterfs": {
    "_executor_comment": [
      "Execute plugin. Possible choices: mock, ssh",
      "mock: This setting is used for testing and development.",
      "      It will not send commands to any node.",
      "ssh:  This setting will notify Heketi to ssh to the nodes.",
      "      It will need the values in sshexec to be configured.",
      "kubernetes: Communicate with GlusterFS containers over",
      "            Kubernetes exec api."
    ],
    "executor": "ssh",

    "_sshexec_comment": "SSH username and private key file information",
    "sshexec": {
      "keyfile": "/home/heketi/.ssh/id_rsa",
      "user": "heketi",
      "port": "20443",
      "sudo": true,
      "fstab": "Optional: Specify fstab file on node.  Default is /etc/fstab"
    },

    "_kubeexec_comment": "Kubernetes configuration",
    "kubeexec": {
      "host" :"https://kubernetes.host:8443",
      "cert" : "/path/to/crt.file",
      "insecure": false,
      "user": "kubernetes username",
      "password": "password for kubernetes user",
      "namespace": "OpenShift project or Kubernetes namespace",
      "fstab": "Optional: Specify fstab file on node.  Default is /etc/fstab"
    },

    "_db_comment": "Database file name",
    "db": "/var/lib/heketi/heketi.db",

    "_loglevel_comment": [
      "Set log level. Choices are:",
      "  none, critical, error, warning, info, debug",
      "Default is warning"
    ],
    "loglevel" : "debug"
  }
}

[root@m-30-2 gluster]# pwd
/opt/gluster
[root@m-30-2 gluster]# cat topology.json
{
    "clusters": [
        {
            "nodes": [
                {
                    "node": {
                        "hostnames": {
                            "manage": [
                                "172.16.30.1"
                            ],
                            "storage": [
                                "172.16.30.1"
                            ]
                        },
                        "zone": 1
                    },
                    "devices": [
                        "/dev/sdb"
                    ]
                },
                {
                    "node": {
                        "hostnames": {
                            "manage": [
                                "172.16.30.2"
                            ],
                            "storage": [
                                "172.16.30.2"
                            ]
                        },
                        "zone": 1
                    },
                    "devices": [
                        "/dev/sdb"
                    ]
                },
                {
                    "node": {
                        "hostnames": {
                            "manage": [
                                "172.16.30.3"
                            ],
                            "storage": [
                                "172.16.30.3"
                            ]
                        },
                        "zone": 1
                    },
                    "devices": [
                        "/dev/sdb"
                    ]
                }
            ]
        }
    ]
}
export HEKETI_CLI_SERVER=http://172.16.30.2:8090
heketi-cli topology load --json=topology.json

有时候磁盘上有标记需要清除一下wipefs --all /dev/sdb

helm 安装小计

kubectl delete svc tiller-deploy -n kube-system
kubectl -n kube-system delete deploy tiller-deploy
kubectl create serviceaccount --namespace kube-system tiller
kubectl create clusterrolebinding tiller-cluster-rule --clusterrole=cluster-admin --serviceaccount=kube-system:tiller
helm init --service-account tiller