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28.kubernetes

时间:2019-08-29 00:12:54      阅读:143      评论:0      收藏:0      [点我收藏+]

标签:flannel   影响   pass   加速   mode   pack   within   exe   节点配置   

1.kubernetes介绍

1.1k8s核心功能

1.自我修复
2.服务发现和负载均衡
3.自动部署和回滚
4.弹性伸缩

1.2k8s应用场景

1.方便业务升级,增加新功能
2.支持更好的性能扩展
3.k8s弹性伸缩

技术图片

1.3k8s核心组件和架构

技术图片
技术图片
技术图片

2.安装

2.1环境准备

技术图片

建议使用7.4,7.5会有些问题
[root@k8s-node1 ~]# cat /etc/redhat-release 
CentOS Linux release 7.4.1708 (Core) 

[root@k8s-node1 ~]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
10.0.0.11 k8s-master
10.0.0.12 k8s-node1 
10.0.0.13 k8s-node2 

[root@k8s-master ~]# systemctl stop firewalld
[root@k8s-master ~]# systemctl disable firewalld
[root@k8s-master ~]# cat /etc/selinux/config 

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=disabled
# SELINUXTYPE= can take one of three two values:
#     targeted - Targeted processes are protected,
#     minimum - Modification of targeted policy. Only selected processes are protected. 
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted 

[root@k8s-master ~]# systemctl stop NetworkManager
[root@k8s-master ~]# systemctl disable NetworkManager
[root@k8s-master ~]# systemctl stop postfix
[root@k8s-master ~]# systemctl disable postfix
Removed symlink /etc/systemd/system/multi-user.target.wants/postfix.service.
[root@k8s-master ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

[root@k8s-master ~]# yum install -y net-tools vim lrzsz wget tree screen lsof tcpdump

2.2-master安装etcd服务

安装:
[root@k8s-master ~]#yum install etcd -y
[root@k8s-master ~]#vim /etc/etcd/etcd.conf
6行:ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"
21行:ETCD_ADVERTISE_CLIENT_URLS="http://10.0.0.11:2379"

[root@k8s-master ~]# systemctl start etcd.service 
[root@k8s-master ~]# systemctl enable etcd.service 
Created symlink from /etc/systemd/system/multi-user.target.wants/etcd.service to /usr/lib/systemd/system/etcd.service.

测试:
[root@k8s-master ~]# etcdctl set testdir/testkey0 0
0
[root@k8s-master ~]# etcdctl get testdir/testkey0
0
[root@k8s-master ~]# etcdctl -C http://10.0.0.11:2379 cluster-health
member 8e9e05c52164694d is healthy: got healthy result from http://10.0.0.11:2379
cluster is healthy
[root@k8s-master ~]# 
#2379对外提供服务使用的,k8s往etcd中写入数据,使用改端口
#2380集群间数据同步,使用2380端口
[root@k8s-master ~]# netstat -antlp
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 127.0.0.1:6379          0.0.0.0:*               LISTEN      1416/redis-server 1 
tcp        0      0 127.0.0.1:2380          0.0.0.0:*               LISTEN      1771/etcd           
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      1085/sshd           
tcp        0      0 127.0.0.1:9002          0.0.0.0:*               LISTEN      1449/python         
tcp        0      0 0.0.0.0:3306            0.0.0.0:*               LISTEN      1372/mysqld         
tcp        0      0 127.0.0.1:54748         127.0.0.1:2379          ESTABLISHED 1771/etcd           
tcp        0      0 10.0.0.11:33926         10.0.0.11:2379          TIME_WAIT   -                   
tcp        0      0 10.0.0.11:33924         10.0.0.11:2379          TIME_WAIT   -                   
tcp        0      0 10.0.0.11:22            10.0.0.1:3116           ESTABLISHED 1480/sshd: root@pts 
tcp        0     52 10.0.0.11:22            10.0.0.1:4765           ESTABLISHED 1698/sshd: root@pts 
tcp6       0      0 :::2379                 :::*                    LISTEN      1771/etcd           
tcp6       0      0 :::80                   :::*                    LISTEN      1428/httpd          
tcp6       0      0 :::22                   :::*                    LISTEN      1085/sshd           
tcp6       0      0 127.0.0.1:2379          127.0.0.1:54748         ESTABLISHED 1771/etcd 

2.3安装kubernetes master节点

[root@k8s-master ~]# yum install kubernetes-master.x86_64 -y

#apiserver配置,apiserver在哪个服务器上,那个就是master节点
#下面是修改的地方
[root@k8s-master ~]# vim /etc/kubernetes/apiserver
# The address on the local server to listen to.
KUBE_API_ADDRESS="--insecure-bind-address=0.0.0.0"

# The port on the local server to listen on.
KUBE_API_PORT="--port=8080"

# Port minions listen on
KUBELET_PORT="--kubelet-port=10250"

# Comma separated list of nodes in the etcd cluster
KUBE_ETCD_SERVERS="--etcd-servers=http://10.0.0.11:2379"

#controller-manager, scheduler, and proxy共用一个配置文件
[root@k8s-master ~]# vim /etc/kubernetes/config
# How the controller-manager, scheduler, and proxy find the apiserver
KUBE_MASTER="--master=http://10.0.0.11:8080"

[root@k8s-master ~]# systemctl start kube-apiserver.service
[root@k8s-master ~]# systemctl start kube-controller-manager.service
[root@k8s-master ~]# systemctl start kube-scheduler.service
[root@k8s-master ~]# systemctl enable kube-apiserver.service 
Created symlink from /etc/systemd/system/multi-user.target.wants/kube-apiserver.service to /usr/lib/systemd/system/kube-apiserver.service.
[root@k8s-master ~]# systemctl enable kube-controller-manager.service 
Created symlink from /etc/systemd/system/multi-user.target.wants/kube-controller-manager.service to /usr/lib/systemd/system/kube-controller-manager.service.
[root@k8s-master ~]# systemctl enable kube-scheduler.service 
Created symlink from /etc/systemd/system/multi-user.target.wants/kube-scheduler.service to /usr/lib/systemd/system/kube-scheduler.service.
[root@k8s-master ~]# 
[root@k8s-master ~]# kubectl get componentstatus 
NAME                 STATUS    MESSAGE             ERROR
controller-manager   Healthy   ok                  
scheduler            Healthy   ok                  
etcd-0               Healthy   {"health":"true"}   
[root@k8s-master ~]# 

2.4安装kubernetes node节点

#1.每个节点都安装Node
yum install kubernetes-node.x86_64 -y

#2.node1和node2上修改配置文件,master上已经配置完了,不需要改了
[root@k8s-node1 ~]# vim /etc/kubernetes/config
[root@k8s-node2 ~]# vim /etc/kubernetes/config
# How the controller-manager, scheduler, and proxy find the apiserver
KUBE_MASTER="--master=http://10.0.0.11:8080"

#3.master上修改kuberlet配置文件
[root@k8s-master ~]# cat /etc/kubernetes/kubelet 
###
# kubernetes kubelet (minion) config

# The address for the info server to serve on (set to 0.0.0.0 or "" for all interfaces)
KUBELET_ADDRESS="--address=10.0.0.11"

# The port for the info server to serve on
KUBELET_PORT="--port=10250"

# You may leave this blank to use the actual hostname
KUBELET_HOSTNAME="--hostname-override=k8s-master"

# location of the api-server
KUBELET_API_SERVER="--api-servers=http://10.0.0.11:8080"

# pod infrastructure container
KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=registry.access.redhat.com/rhel7/pod-infrastructure:latest"

# Add your own!
KUBELET_ARGS=""
[root@k8s-master ~]#
[root@k8s-master ~]# systemctl start kubelet.service
[root@k8s-master ~]# systemctl start kube-proxy.service
[root@k8s-master ~]# systemctl enable kubelet.service 
Created symlink from /etc/systemd/system/multi-user.target.wants/kubelet.service to /usr/lib/systemd/system/kubelet.service.
[root@k8s-master ~]# systemctl enable kube-proxy.service 
Created symlink from /etc/systemd/system/multi-user.target.wants/kube-proxy.service to /usr/lib/systemd/system/kube-proxy.service.
[root@k8s-master ~]# 
[root@k8s-master ~]# kubectl get nodes
NAME         STATUS    AGE
k8s-master   Ready     1m

#4.node1节点
[root@k8s-node1 ~]# cat /etc/kubernetes/kubelet 
###
# kubernetes kubelet (minion) config

# The address for the info server to serve on (set to 0.0.0.0 or "" for all interfaces)
KUBELET_ADDRESS="--address=10.0.0.12"

# The port for the info server to serve on
KUBELET_PORT="--port=10250"

# You may leave this blank to use the actual hostname
KUBELET_HOSTNAME="--hostname-override=k8s-node1"

# location of the api-server
KUBELET_API_SERVER="--api-servers=http://10.0.0.11:8080"

# pod infrastructure container
KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=registry.access.redhat.com/rhel7/pod-infrastructure:latest"

# Add your own!
KUBELET_ARGS=""
[root@k8s-node1 ~]# systemctl start kubelet.service 
[root@k8s-node1 ~]# systemctl start kube-proxy.service 
[root@k8s-node1 ~]# systemctl enable kubelet.service 
Created symlink from /etc/systemd/system/multi-user.target.wants/kubelet.service to /usr/lib/systemd/system/kubelet.service.
[root@k8s-node1 ~]# systemctl enable kube-proxy.service 
Created symlink from /etc/systemd/system/multi-user.target.wants/kube-proxy.service to /usr/lib/systemd/system/kube-proxy.service.
[root@k8s-node1 ~]# 

#5.node2节点
[root@k8s-node2 ~]# cat /etc/kubernetes/kubelet 
###
# kubernetes kubelet (minion) config

# The address for the info server to serve on (set to 0.0.0.0 or "" for all interfaces)
KUBELET_ADDRESS="--address=10.0.0.13"

# The port for the info server to serve on
KUBELET_PORT="--port=10250"

# You may leave this blank to use the actual hostname
KUBELET_HOSTNAME="--hostname-override=k8s-node2"

# location of the api-server
KUBELET_API_SERVER="--api-servers=http://10.0.0.11:8080"

# pod infrastructure container
KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=registry.access.redhat.com/rhel7/pod-infrastructure:latest"

# Add your own!
KUBELET_ARGS=""
[root@k8s-node2 ~]# systemctl start kubelet.service
[root@k8s-node2 ~]# systemctl start kube-proxy.service 
[root@k8s-node2 ~]# systemctl enable kubelet.service 
Created symlink from /etc/systemd/system/multi-user.target.wants/kubelet.service to /usr/lib/systemd/system/kubelet.service.
[root@k8s-node2 ~]# systemctl enable kube-proxy.service 
Created symlink from /etc/systemd/system/multi-user.target.wants/kube-proxy.service to /usr/lib/systemd/system/kube-proxy.service.

#6.master节点上查看
[root@k8s-master ~]# kubectl get nodes
NAME         STATUS    AGE
k8s-master   Ready     8m
k8s-node1    Ready     2m
k8s-node2    Ready     3m
[root@k8s-master ~]# 

2.5所有node节点配置flannel网络插件

#1.所有节点安装flannel
yum install flannel -y

#2.master修改配置文件
[root@k8s-master ~]# sed -i ‘s#http://127.0.0.1:2379#http://10.0.0.11:2379#g‘ /etc/sysconfig/flanneld

[root@k8s-master ~]# cat /etc/sysconfig/flanneld 
# Flanneld configuration options  

# etcd url location.  Point this to the server where etcd runs
FLANNEL_ETCD_ENDPOINTS="http://10.0.0.11:2379"

# etcd config key.  This is the configuration key that flannel queries
# For address range assignment
FLANNEL_ETCD_PREFIX="/atomic.io/network"

# Any additional options that you want to pass
#FLANNEL_OPTIONS=""
#2.1master容器的ip地址范围
[root@k8s-master ~]# etcdctl mk /atomic.io/network/config ‘{ "Network": "172.16.0.0/16" }‘
{ "Network": "172.16.0.0/16" }

#2.2master节点重启服务
[root@k8s-master ~]# systemctl start flanneld.service 
[root@k8s-master ~]# systemctl enable flanneld.service 
Created symlink from /etc/systemd/system/multi-user.target.wants/flanneld.service to /usr/lib/systemd/system/flanneld.service.
Created symlink from /etc/systemd/system/docker.service.wants/flanneld.service to /usr/lib/systemd/system/flanneld.service.
[root@k8s-master ~]# 

[root@k8s-master ~]# service docker restart
Redirecting to /bin/systemctl restart docker.service
[root@k8s-master ~]# systemctl restart kube-apiserver.service
[root@k8s-master ~]# systemctl restart kube-controller-manager.service
[root@k8s-master ~]# systemctl restart kube-scheduler.service
[root@k8s-master ~]# 
#2.3master查看docker网段
[root@k8s-master ~]# ifconfig
#这里是172.16网段
docker0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        inet 172.16.93.1  netmask 255.255.255.0  broadcast 0.0.0.0
        ether 02:42:35:9d:71:e8  txqueuelen 0  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

docker_gwbridge: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        inet 172.18.0.1  netmask 255.255.0.0  broadcast 0.0.0.0
        ether 02:42:e8:6b:f7:fe  txqueuelen 0  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 3  bytes 144 (144.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.0.0.11  netmask 255.255.255.0  broadcast 10.0.0.255
        inet6 fe80::20c:29ff:fee1:5b21  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:e1:5b:21  txqueuelen 1000  (Ethernet)
        RX packets 70391  bytes 88495191 (84.3 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 36010  bytes 5584671 (5.3 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

eth1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.16.1.11  netmask 255.255.255.0  broadcast 172.16.1.255
        inet6 fe80::20c:29ff:fee1:5b2b  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:e1:5b:2b  txqueuelen 1000  (Ethernet)
        RX packets 42  bytes 2520 (2.4 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 12  bytes 868 (868.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
#这里是172.16网段
flannel0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1472
        inet 172.16.93.0  netmask 255.255.0.0  destination 172.16.93.0
        inet6 fe80::32f2:2a0e:a07e:990d  prefixlen 64  scopeid 0x20<link>
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 500  (UNSPEC)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 3  bytes 144 (144.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1  (Local Loopback)
        RX packets 90828  bytes 43054764 (41.0 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 90828  bytes 43054764 (41.0 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

[root@k8s-master ~]# 

#3.node节点:
[root@k8s-node1 ~]# sed -i ‘s#http://127.0.0.1:2379#http://10.0.0.11:2379#g‘ /etc/sysconfig/flanneld
[root@k8s-node1 ~]# systemctl start flanneld.service 
[root@k8s-node1 ~]# systemctl enable flanneld.service 
Created symlink from /etc/systemd/system/multi-user.target.wants/flanneld.service to /usr/lib/systemd/system/flanneld.service.
Created symlink from /etc/systemd/system/docker.service.wants/flanneld.service to /usr/lib/systemd/system/flanneld.service.
[root@k8s-node1 ~]# systemctl restart docker.service 
[root@k8s-node1 ~]# systemctl restart kubelet.service
[root@k8s-node1 ~]# systemctl restart kube-proxy.service
[root@k8s-node1 ~]# 

[root@k8s-node2 ~]#sed -i ‘s#http://127.0.0.1:2379#http://10.0.0.11:2379#g‘ /etc/sysconfig/flanneld
[root@k8s-node2 ~]# systemctl start flanneld.service 
[root@k8s-node2 ~]# systemctl enable flanneld.service 
Created symlink from /etc/systemd/system/multi-user.target.wants/flanneld.service to /usr/lib/systemd/system/flanneld.service.
Created symlink from /etc/systemd/system/docker.service.wants/flanneld.service to /usr/lib/systemd/system/flanneld.service.
[root@k8s-node2 ~]# systemctl restart docker.service
[root@k8s-node2 ~]# systemctl restart kube-proxy.service
[root@k8s-node2 ~]# systemctl restart kubelet.service 
[root@k8s-node2 ~]# 

#4.测试跨宿主机容器之间的互通性
#4.1所有节点
[root@k8s-master ~]# docker pull busybox
[root@k8s-node1 ~]# docker pull busybox
[root@k8s-node2 ~]# docker pull busybox
使用xshell的send text to all sessions
[root@k8s-master ~]# docker run -it busybox
/ # ifconfig
eth0      Link encap:Ethernet  HWaddr 02:42:AC:10:5D:02  
          inet addr:172.16.93.2  Bcast:0.0.0.0  Mask:255.255.255.0
          inet6 addr: fe80::42:acff:fe10:5d02/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1472  Metric:1
          RX packets:16 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:1296 (1.2 KiB)  TX bytes:648 (648.0 B)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
#4.2节点之间互ping
/ # 
/ # ping 172.16.79.2
PING 172.16.79.2 (172.16.79.2): 56 data bytes
^C
--- 172.16.79.2 ping statistics ---
2 packets transmitted, 0 packets received, 100% packet loss
/ # ping 172.16.48.2
PING 172.16.48.2 (172.16.48.2): 56 data bytes
^C
--- 172.16.48.2 ping statistics ---
11 packets transmitted, 0 packets received, 100% packet loss
/ # 

#4.3容器间ping不通解决办法:
原因是docker1.13版本中,把FORWARD给Drop了
[root@k8s-master ~]# iptables -P FORWARD ACCEPT
[root@k8s-node1 ~]# iptables -P FORWARD ACCEPT
[root@k8s-node2 ~]# iptables -P FORWARD ACCEPT
#修改配置文件,永久生效,三台服务器都要添加
vim  /usr/lib/systemd/system/docker.service
Environment=PATH=/usr/libexec/docker:/usr/bin:/usr/sbin
#添加的内容
ExecStartPost=/usr/sbin/iptables  -P FORWARD  ACCEPT
#操作完成后,reload一下
systemctl daemon-reload

#4.4再次尝试
--- 172.16.48.2 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 0.828/0.888/0.949 ms
/ # ping 172.16.79.2
PING 172.16.79.2 (172.16.79.2): 56 data bytes
64 bytes from 172.16.79.2: seq=0 ttl=60 time=0.877 ms
^C
--- 172.16.79.2 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 0.877/0.877/0.877 ms
/ # 

3.常用资源使用

3.1创建一个pod

#1.编辑yaml文件
vi  nginx_pod.yaml
apiVersion: v1
kind: Pod
metadata:
  name: nginx
  labels:
    app: web
spec:
  containers:
    - name: nginx
      image: nginx:1.13
      ports:
        - containerPort: 80

#2.创建pod
#2.1报错1
[root@k8s-master k8s]# kubectl create -f  nginx_pod.yaml
Error from server (ServerTimeout): error when creating "nginx_pod.yaml": No API token found for service account "default", retry after the token is automatically created and added to the service account
解决方法,删除ServiceAccount
[root@k8s-master k8s]#vim /etc/kubernetes/apiserver
KUBE_ADMISSION_CONTROL="--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ResourceQuota"
systemctl restart kube-apiserver.service
#2.2再次创建Pod
[root@k8s-master k8s]# kubectl create -f  nginx_pod.yaml
pod "nginx" created
[root@k8s-master k8s]#
#2.3查看创建的pod
[root@k8s-master k8s]#
[root@k8s-master k8s]# kubectl get nodes
NAME         STATUS    AGE
k8s-master   Ready     1h
k8s-node1    Ready     1h
k8s-node2    Ready     1h
[root@k8s-master k8s]# kubectl get componentstatus 
NAME                 STATUS    MESSAGE             ERROR
controller-manager   Healthy   ok                  
scheduler            Healthy   ok                  
etcd-0               Healthy   {"health":"true"}   
[root@k8s-master k8s]#
[root@k8s-master k8s]# kubectl get pod
NAME      READY     STATUS              RESTARTS   AGE
nginx     0/1       ContainerCreating   0          55s
[root@k8s-master k8s]# kubectl get pod nginx
NAME      READY     STATUS              RESTARTS   AGE
nginx     0/1       ContainerCreating   0          2m
[root@k8s-master k8s]# 
#一直处于containerCreating状态
#2.4查看该pod错误信息2
[root@k8s-master k8s]# kubectl describe pod nginx 
Name:       nginx
Namespace:  default
Node:       k8s-node2/10.0.0.13
Start Time: Wed, 28 Aug 2019 15:43:09 +0800
Labels:     app=web
Status:     Pending
IP:     
Controllers:    <none>
Containers:
  nginx:
    Container ID:       
    Image:          nginx:1.13
    Image ID:           
    Port:           80/TCP
    State:          Waiting
      Reason:           ContainerCreating
    Ready:          False
    Restart Count:      0
    Volume Mounts:      <none>
    Environment Variables:  <none>
Conditions:
  Type      Status
  Initialized   True 
  Ready     False 
  PodScheduled  True 
No volumes.
QoS Class:  BestEffort
Tolerations:    <none>
Events:
  FirstSeen LastSeen    Count   From            SubObjectPath   Type        Reason      Message
  --------- --------    -----   ----            -------------   --------    ------      -------
  3m        3m      1   {default-scheduler }            Normal      Scheduled   Successfully assigned nginx to k8s-node2
  2m        15s     10  {kubelet k8s-node2}         Warning     FailedSync  Error syncing pod, skipping: failed to "StartContainer" for "POD" with ImagePullBackOff: "Back-off pulling image \"registry.access.redhat.com/rhel7/pod-infrastructure:latest\""

  3m    3s  5   {kubelet k8s-node2}     Warning FailedSync  Error syncing pod, skipping: failed to "StartContainer" for "POD" with ErrImagePull: "image pull failed for registry.access.redhat.com/rhel7/pod-infrastructure:latest, this may be because there are no credentials on this request.  details: (open /etc/docker/certs.d/registry.access.redhat.com/redhat-ca.crt: no such file or directory)"

[root@k8s-master k8s]# 
#2.5解决方法
从上面看到,分配到了node2节点上
搜索pod-infrastructure镜像,选中第二个
[root@k8s-node2 ~]# docker search pod-infrastructure
INDEX       NAME                                          DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
docker.io   docker.io/neurons/pod-infrastructure          k8s pod 基础容器镜像                                  2                    
docker.io   docker.io/tianyebj/pod-infrastructure         registry.access.redhat.com/rhel7/pod-infra...   2                    
docker.io   docker.io/w564791/pod-infrastructure          latest                                          1                    

[root@k8s-node2 ~]# vim /etc/kubernetes/kubelet 
# pod infrastructure container
KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=docker.io/tianyebj/pod-infrastructure:latest"
[root@k8s-node2 ~]# systemctl restart kubelet.service

#2.6等待一会再次查看
也可查看镜像临时下载路径中是否有内容,来查看是否在pull
[root@k8s-master k8s]# ls /var/lib/docker/tmp/
#我这里已经Pull成功了,如果不成功,就要使用能够上网的机器进行Pull,然后使用docker的save和load来进行导入
[root@k8s-master k8s]# kubectl describe pod nginx 
Name:       nginx
Namespace:  default
Node:       k8s-node2/10.0.0.13
Start Time: Wed, 28 Aug 2019 15:43:09 +0800
Labels:     app=web
Status:     Running
IP:     172.16.48.2
Controllers:    <none>
Containers:
  nginx:
    Container ID:       docker://fcdfa71abdb58c10a40b81b3546545253e13b5aafe63d458008da4d8d96b0623
    Image:          nginx:1.13
    Image ID:           docker-pullable://docker.io/nginx@sha256:b1d09e9718890e6ebbbd2bc319ef1611559e30ce1b6f56b2e3b479d9da51dc35
    Port:           80/TCP
    State:          Running
      Started:          Wed, 28 Aug 2019 15:56:36 +0800
    Ready:          True
    Restart Count:      0
    Volume Mounts:      <none>
    Environment Variables:  <none>
Conditions:
  Type      Status
  Initialized   True 
  Ready     True 
  PodScheduled  True 
No volumes.
QoS Class:  BestEffort
Tolerations:    <none>
Events:
  FirstSeen LastSeen    Count   From            SubObjectPath   Type        Reason      Message
  --------- --------    -----   ----            -------------   --------    ------      -------
  16m       16m     1   {default-scheduler }            Normal      Scheduled   Successfully assigned nginx to k8s-node2
  16m       10m     6   {kubelet k8s-node2}         Warning     FailedSync  Error syncing pod, skipping: failed to "StartContainer" for "POD" with ErrImagePull: "image pull failed for registry.access.redhat.com/rhel7/pod-infrastructure:latest, this may be because there are no credentials on this request.  details: (open /etc/docker/certs.d/registry.access.redhat.com/redhat-ca.crt: no such file or directory)"

  15m   5m  45  {kubelet k8s-node2}     Warning FailedSync  Error syncing pod, skipping: failed to "StartContainer" for "POD" with ImagePullBackOff: "Back-off pulling image \"registry.access.redhat.com/rhel7/pod-infrastructure:latest\""

  3m    3m  1   {kubelet k8s-node2} spec.containers{nginx}  Normal  Pulling         pulling image "nginx:1.13"
  3m    2m  2   {kubelet k8s-node2}             Warning MissingClusterDNS   kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to DNSDefault policy.
  2m    2m  1   {kubelet k8s-node2} spec.containers{nginx}  Normal  Pulled          Successfully pulled image "nginx:1.13"
  2m    2m  1   {kubelet k8s-node2} spec.containers{nginx}  Normal  Created         Created container with docker id fcdfa71abdb5; Security:[seccomp=unconfined]
  2m    2m  1   {kubelet k8s-node2} spec.containers{nginx}  Normal  Started         Started container with docker id fcdfa71abdb5
[root@k8s-master k8s]# 
#2.7node2上查看pull下来的镜像docker.io/tianyebj/pod-infrastructure
[root@k8s-node2 ~]# docker images
REPOSITORY                              TAG                 IMAGE ID            CREATED             SIZE
10.0.0.63/library/busybox               latest              db8ee88ad75f        5 weeks ago         1.22 MB
docker.io/busybox                       latest              db8ee88ad75f        5 weeks ago         1.22 MB
docker.io/nginx                         1.13                ae513a47849c        16 months ago       109 MB
docker.io/tianyebj/pod-infrastructure   latest              34d3450d733b        2 years ago         205 MB
docker.io/progrium/consul               latest              09ea64205e55        4 years ago         69.4 MB
[root@k8s-node2 ~]# 

#3.删除镜像
[root@k8s-master k8s]# kubectl delete pod nginx 
pod "nginx" deleted
[root@k8s-master k8s]# kubectl get pods
No resources found.
[root@k8s-master k8s]# 

#4.创建私有仓库,节省流量,节省带宽
企业中可以使用harbor私有仓库
#4.1master节点拉取registry镜像
[root@k8s-master k8s]# docker pull registry
Using default tag: latest
Trying to pull repository docker.io/library/registry ... 
latest: Pulling from docker.io/library/registry
Digest: sha256:8004747f1e8cd820a148fb7499d71a76d45ff66bac6a29129bfdbfdc0154d146
Status: Image is up to date for docker.io/registry:latest
#4.2master节点启动私有仓库
[root@k8s-master k8s]# docker run -d -p 5000:5000 --restart=always --name registry -v /opt/myregistry:/var/lib/registry  registry
c60f03647fa50c1f515b90b92ea3aa54ba8c6fe46c5ae166bd88a9154db64568
[root@k8s-master k8s]# 
[root@k8s-master k8s]# docker ps -a
CONTAINER ID        IMAGE               COMMAND                  CREATED              STATUS                      PORTS                    NAMES
c60f03647fa5        registry            "/entrypoint.sh /e..."   About a minute ago   Up About a minute           0.0.0.0:5000->5000/tcp   registry
50ad15d96e3b        busybox             "sh"                     About an hour ago    Exited (0) 55 minutes ago                            quizzical_murdock
[root@k8s-master k8s]# 

#4.2node2节点把刚刚pull下来的pod-infrastructure上传到私有仓库中
[root@k8s-node2 ~]# docker tag docker.io/tianyebj/pod-infrastructure 10.0.0.11:5000/pod-infrastructure:latest
[root@k8s-node2 ~]# docker push 10.0.0.11:5000/pod-infrastructure:latest
The push refers to a repository [10.0.0.11:5000/pod-infrastructure
Get https://10.0.0.11:5000/v1/_ping: http: server gave HTTP response to HTTPS client
#配置镜像加速和信任
[root@k8s-node1 ~]# cat /etc/sysconfig/docker
# /etc/sysconfig/docker

# Modify these options if you want to change the way the docker daemon runs
#OPTIONS=‘--selinux-enabled --log-driver=journald --signature-verification=false‘
OPTIONS=‘--selinux-enabled --log-driver=journald --signature-verification=false --registry-mirror=https://registry.docker-cn.com --insecure-registry=10.0.0.11:5000‘
[root@k8s-node1 ~]#systemctl restart docker.service

[root@k8s-node2 ~]# docker push 10.0.0.11:5000/pod-infrastructure:ltest
The push refers to a repository [10.0.0.11:5000/pod-infrastructure]
ba3d4cbbb261: Pushed 
0a081b45cb84: Pushed 
df9d2808b9a9: Pushed 
ltest: digest: sha256:a378b2d7a92231ffb07fdd9dbd2a52c3c439f19c8d675a0d8d9ab74950b15a1b size: 948
[root@k8s-node2 ~]# 
#由于需要nginx镜像,所以把nginx也Push到私有仓库
[root@k8s-node2 ~]# docker tag docker.io/nginx:1.13 10.0.0.11:5000/nginx:1.13
[root@k8s-node2 ~]# docker push 10.0.0.11:5000/nginx:1.13
The push refers to a repository [10.0.0.11:5000/nginx]
7ab428981537: Pushed 
82b81d779f83: Pushed 
d626a8ad97a1: Pushed 
1.13: digest: sha256:e4f0474a75c510f40b37b6b7dc2516241ffa8bde5a442bde3d372c9519c84d90 size: 948

#4.3所有节点配置
#配置镜像加速和信任
[root@k8s-node1 ~]# cat /etc/sysconfig/docker
# /etc/sysconfig/docker

# Modify these options if you want to change the way the docker daemon runs
#OPTIONS=‘--selinux-enabled --log-driver=journald --signature-verification=false‘
OPTIONS=‘--selinux-enabled --log-driver=journald --signature-verification=false --registry-mirror=https://registry.docker-cn.com --insecure-registry=10.0.0.11:5000‘
[root@k8s-node1 ~]#systemctl restart docker.service
#配置从私有仓库拉取pod-infrastructure
[root@k8s-node1 ~]# cat /etc/kubernetes/kubelet 
KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=10.0.0.11:5000/pod-infrastructure:latest"
[root@k8s-node1 ~]#systemctl restart kubelet.service

#4.4master节点查看pod状态,已经成功
[root@k8s-master k8s]# kubectl get pods
NAME      READY     STATUS    RESTARTS   AGE
nginx     1/1       Running   0          35m
[root@k8s-master k8s]# 
[root@k8s-master k8s]# kubectl describe pod nginx 
Name:       nginx
Namespace:  default
Node:       k8s-node1/10.0.0.12
Start Time: Wed, 28 Aug 2019 16:14:30 +0800
Labels:     app=web
Status:     Running
IP:     172.16.79.2
Controllers:    <none>
Containers:
  nginx:
    Container ID:       docker://13374ea686595b25b07bb1b2a5228c58bd818455c42e2344bcb200990a94ec69
    Image:          nginx:1.13
    Image ID:           docker-pullable://docker.io/nginx@sha256:b1d09e9718890e6ebbbd2bc319ef1611559e30ce1b6f56b2e3b479d9da51dc35
    Port:           80/TCP
    State:          Running
      Started:          Wed, 28 Aug 2019 16:44:13 +0800
    Ready:          True
    Restart Count:      0
    Volume Mounts:      <none>
    Environment Variables:  <none>
Conditions:
  Type      Status
  Initialized   True 
  Ready     True 
  PodScheduled  True 
No volumes.
QoS Class:  BestEffort
Tolerations:    <none>
Events:
  FirstSeen LastSeen    Count   From            SubObjectPath   Type        Reason      Message
  --------- --------    -----   ----            -------------   --------    ------      -------
  30m       30m     1   {default-scheduler }            Normal      Scheduled   Successfully assigned nginx to k8s-node1
  30m       20m     7   {kubelet k8s-node1}         Warning     FailedSync  Error syncing pod, skipping: failed to "StartContainer" for "POD" with ErrImagePull: "image pull failed for registry.access.redhat.com/rhel7/pod-infrastructure:latest, this may be because there are no credentials on this request.  details: (open /etc/docker/certs.d/registry.access.redhat.com/redhat-ca.crt: no such file or directory)"

  30m   17m 56  {kubelet k8s-node1}     Warning FailedSync  Error syncing pod, skipping: failed to "StartContainer" for "POD" with ImagePullBackOff: "Back-off pulling image \"registry.access.redhat.com/rhel7/pod-infrastructure:latest\""

  16m   16m 3   {kubelet k8s-node1}     Warning FailedSync  Error syncing pod, skipping: failed to "StartContainer" for "POD" with ErrImagePull: "image pull failed for registry.access.redhat.com/rhel7/pod-infrastructure:latest, this may be because there are no credentials on this request.  details: (open /etc/docker/certs.d/registry.access.redhat.com/redhat-ca.crt: no such file or directory)"

  16m   15m 3   {kubelet k8s-node1}     Warning FailedSync  Error syncing pod, skipping: failed to "StartContainer" for "POD" with ImagePullBackOff: "Back-off pulling image \"registry.access.redhat.com/rhel7/pod-infrastructure:latest\""

  15m   12m 5   {kubelet k8s-node1}     Warning FailedSync  Error syncing pod, skipping: failed to "StartContainer" for "POD" with ErrImagePull: "Error: image pod-infrastructure:latest not found"

  14m   9m  22  {kubelet k8s-node1}     Warning FailedSync  Error syncing pod, skipping: failed to "StartContainer" for "POD" with ImagePullBackOff: "Back-off pulling image \"10.0.0.11:5000/pod-infrastructure:latest\""

  2m    2m  1   {kubelet k8s-node1} spec.containers{nginx}  Warning Failed      Failed to pull image "nginx:1.13": net/http: request canceled
  2m    2m  1   {kubelet k8s-node1}             Warning FailedSync  Error syncing pod, skipping: failed to "StartContainer" for "nginx" with ErrImagePull: "net/http: request canceled"

  2m    2m  1   {kubelet k8s-node1} spec.containers{nginx}  Normal  BackOff     Back-off pulling image "nginx:1.13"
  2m    2m  1   {kubelet k8s-node1}             Warning FailedSync  Error syncing pod, skipping: failed to "StartContainer" for "nginx" with ImagePullBackOff: "Back-off pulling image \"nginx:1.13\""

  9m    2m  2   {kubelet k8s-node1} spec.containers{nginx}  Normal  Pulling         pulling image "nginx:1.13"
  9m    1m  2   {kubelet k8s-node1}             Warning MissingClusterDNS   kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to DNSDefault policy.
  1m    1m  1   {kubelet k8s-node1} spec.containers{nginx}  Normal  Pulled          Successfully pulled image "nginx:1.13"
  1m    1m  1   {kubelet k8s-node1} spec.containers{nginx}  Normal  Created         Created container with docker id 13374ea68659; Security:[seccomp=unconfined]
  1m    1m  1   {kubelet k8s-node1} spec.containers{nginx}  Normal  Started         Started container with docker id 13374ea68659
[root@k8s-master k8s]# cat 

#5.使用私有仓库构建pod
[root@k8s-master k8s]# cat nginx_pod.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: test
  labels:
    app: web
spec:
  containers:
    - name: nginx
      image: 10.0.0.11:5000/nginx:1.13
      ports:
        - containerPort: 80
[root@k8s-master k8s]# 
#很快就构建成功了
[root@k8s-master k8s]# kubectl create -f nginx_pod.yaml 
pod "test" created
[root@k8s-master k8s]# kubectl get pod
NAME      READY     STATUS    RESTARTS   AGE
nginx     1/1       Running   0          45m
test      1/1       Running   0          15s
[root@k8s-master k8s]#  kubectl describe pod test
Name:       test
Namespace:  default
Node:       k8s-node2/10.0.0.13
Start Time: Wed, 28 Aug 2019 16:59:30 +0800
Labels:     app=web
Status:     Running
IP:     172.16.48.2
Controllers:    <none>
Containers:
  nginx:
    Container ID:       docker://964ab40f1fdf91755e7510d5bf497b50181957e5d4eba51ff04a05899d5fbf11
    Image:          10.0.0.11:5000/nginx:1.13
    Image ID:           docker-pullable://10.0.0.11:5000/nginx@sha256:e4f0474a75c510f40b37b6b7dc2516241ffa8bde5a442bde3d372c9519c84d90
    Port:           80/TCP
    State:          Running
      Started:          Wed, 28 Aug 2019 16:59:30 +0800
    Ready:          True
    Restart Count:      0
    Volume Mounts:      <none>
    Environment Variables:  <none>
Conditions:
  Type      Status
  Initialized   True 
  Ready     True 
  PodScheduled  True 
No volumes.
QoS Class:  BestEffort
Tolerations:    <none>
Events:
  FirstSeen LastSeen    Count   From            SubObjectPath       Type        Reason          Message
  --------- --------    -----   ----            -------------       --------    ------          -------
  2m        2m      1   {default-scheduler }                Normal      Scheduled       Successfully assigned test to k8s-node2
  2m        2m      2   {kubelet k8s-node2}             Warning     MissingClusterDNS   kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to DNSDefault policy.
  2m        2m      1   {kubelet k8s-node2} spec.containers{nginx}  Normal      Pulled          Container image "10.0.0.11:5000/nginx:1.13" already present on machine
  2m        2m      1   {kubelet k8s-node2} spec.containers{nginx}  Normal      Created         Created container with docker id 964ab40f1fdf; Security:[seccomp=unconfined]
  2m        2m      1   {kubelet k8s-node2} spec.containers{nginx}  Normal      Started         Started container with docker id 964ab40f1fdf
[root@k8s-master k8s]# 

3.2pod资源是什么

k8s中创建一个pod资源,控制docker启动两个容器,业务容器nginx和基础pod容器。
#1.查看pod信息
可以看到pod的IP和所在的节点
[root@k8s-master k8s]# kubectl get pod -o wide
NAME      READY     STATUS    RESTARTS   AGE       IP            NODE
nginx     1/1       Running   0          58m       172.16.79.2   k8s-node1
test      1/1       Running   0          13m       172.16.48.2   k8s-node2
[root@k8s-master k8s]# 
#2.访问Pod的IP
[root@k8s-master k8s]# curl -I 172.16.79.2
HTTP/1.1 200 OK
Server: nginx/1.13.12
Date: Wed, 28 Aug 2019 09:13:37 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Mon, 09 Apr 2018 16:01:09 GMT
Connection: keep-alive
ETag: "5acb8e45-264"
Accept-Ranges: bytes

[root@k8s-master k8s]# 
#3.node1,node2上查看容器
[root@k8s-node1 ~]# docker ps -a
CONTAINER ID        IMAGE                                      COMMAND                  CREATED             STATUS                             PORTS                       NAMES
13374ea68659        nginx:1.13                                 "nginx -g ‘daemon ..."   31 minutes ago      Up 31 minutes                                                  k8s_nginx.78d00b5_nginx_default_dc2f032c-c96b-11e9-b75c-000c29e15b21_35d7190a
5289d7fdf594        10.0.0.11:5000/pod-infrastructure:latest   "/pod"                   39 minutes ago      Up 39 minutes                                                  k8s_POD.177f01b0_nginx_default_dc2f032c-c96b-11e9-b75c-000c29e15b21_ee1e6ad2
[root@k8s-node2 ~]# docker ps -a
CONTAINER ID        IMAGE                                      COMMAND                  CREATED             STATUS                         PORTS               NAMES
964ab40f1fdf        10.0.0.11:5000/nginx:1.13                  "nginx -g ‘daemon ..."   15 minutes ago      Up 15 minutes                                      k8s_nginx.91390390_test_default_259f45ce-c972-11e9-b75c-000c29e15b21_7e2518c4
ad6f45f152f8        10.0.0.11:5000/pod-infrastructure:latest   "/pod"                   15 minutes ago      Up 15 minutes                                      k8s_POD.177f01b0_test_default_259f45ce-c972-11e9-b75c-000c29e15b21_a7cfa831
#4.查看IP
#查看Pod容器有ip,nginx容器没有ip,
#nginx容器的网络类型为container,和pod容器共用ip地址
[root@k8s-node1 ~]# docker inspect 5289d7fdf594|grep IPAddress
            "SecondaryIPAddresses": null,
            "IPAddress": "172.16.79.2",
                    "IPAddress": "172.16.79.2",
[root@k8s-node1 ~]# docker inspect 13374ea68659|grep -i network
            "NetworkMode": "container:5289d7fdf594594340f4d82d58f6e9173880c11247862d402f853ee936bbcd6a",
        "NetworkSettings": {
            "Networks": {}
[root@k8s-node1 ~]# 

2.8pod常用操作

 kubectl describe pod test
 kubectl create -f nginx_pod.yaml 
 kubectl get pods
 kubectl delete pod test2
 kubectl delete pod test2 --force --grace-period=0
#1.编写pod.yaml文件
imagePullPolicy:意思是本地有镜像,就不去docker官网去Pull,校验了,可以节省时间
一个pod中创建了两个容器
[root@k8s-master k8s]# cat nginx_pod.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: test3
  labels:
    app: web
spec:
  containers:
    - name: nginx
      image: 10.0.0.11:5000/nginx:1.13
      ports:
        - containerPort: 80
    - name: busybox
      image: docker.io/busybox:latest
      imagePullPolicy: IfNotPresent
      command: ["sleep","3600"]
      ports:
        - containerPort: 80
[root@k8s-master k8s]# 
#2.创建pod
[root@k8s-master k8s]# kubectl create -f nginx_pod.yaml 
pod "test3" created
#3.很快就建好了pod
[root@k8s-master k8s]# kubectl get pods
NAME      READY     STATUS    RESTARTS   AGE
nginx     1/1       Running   0          1h
test      1/1       Running   0          42m
test2     2/2       Running   0          4m
test3     2/2       Running   0          21s
#4.可以看到又新建了三个容器,一个pod容器,两个业务容器,业务容器共用Pod容器的网络
[root@k8s-node2 ~]# docker ps -a
CONTAINER ID        IMAGE                                      COMMAND                  CREATED             STATUS                   PORTS               NAMES
6b3a5f49a2ef        docker.io/busybox:latest                   "sleep 3600"             5 minutes ago       Up 5 minutes                                 k8s_busybox.268a09f9_test3_default_fa1e1433-c977-11e9-b75c-000c29e15b21_65079326
5c123da070d9        10.0.0.11:5000/nginx:1.13                  "nginx -g ‘daemon ..."   5 minutes ago       Up 5 minutes                                 k8s_nginx.91390390_test3_default_fa1e1433-c977-11e9-b75c-000c29e15b21_2af6be9b
3b0017bbfdbb        10.0.0.11:5000/pod-infrastructure:latest   "/pod"                   5 minutes ago       Up 5 minutes                                 k8s_POD.1597245b_test3_default_fa1e1433-c977-11e9-b75c-000c29e15b21_f2c362e9
964ab40f1fdf        10.0.0.11:5000/nginx:1.13                  "nginx -g ‘daemon ..."   47 minutes ago      Up 47 minutes                                k8s_nginx.91390390_test_default_259f45ce-c972-11e9-b75c-000c29e15b21_7e2518c4
ad6f45f152f8        10.0.0.11:5000/pod-infrastructure:latest   "/pod"                   47 minutes ago      Up 47 minutes                                k8s_POD.177f01b0_test_default_259f45ce-c972-11e9-b75c-000c29e15b21_a7cfa831
599b05a0a368        busybox                                    "sh"                     2 hours ago         Exited (0) 2 hours ago                       gracious_brattain
4ace81ed1bf0        progrium/consul                            "/bin/start -serve..."   8 hours ago         Exited (1) 7 hours ago                       consul
[root@k8s-node2 ~]# 
#5.删除pod
[root@k8s-master k8s]# kubectl delete pod test2
pod "test2" deleted
如果删不掉,可以使用强制删除
[root@k8s-master k8s]# kubectl delete pod test2 --force --grace-period=0
[root@k8s-master k8s]# kubectl get pods
NAME      READY     STATUS    RESTARTS   AGE
nginx     1/1       Running   0          1h
test      1/1       Running   0          52m
test3     2/2       Running   0          10m
#6.查看帮助信息
[root@k8s-master k8s]# kubectl explain pod.spec.containers
RESOURCE: containers <[]Object>

DESCRIPTION:
     List of containers belonging to the pod. Containers cannot currently be
     added or removed. There must be at least one container in a Pod. Cannot be
     updated. More info: http://kubernetes.io/docs/user-guide/containers

    A single application container that you want to run within a pod.

FIELDS:
   image    <string>
     Docker image name. More info: http://kubernetes.io/docs/user-guide/images

   name <string> -required-
     Name of the container specified as a DNS_LABEL. Each container in a pod
     must have a unique name (DNS_LABEL). Cannot be updated.

   readinessProbe   <Object>
     Periodic probe of container service readiness. Container will be removed
     from service endpoints if the probe fails. Cannot be updated. More info:
     http://kubernetes.io/docs/user-guide/pod-states#container-probes

   stdin    <boolean>
     Whether this container should allocate a buffer for stdin in the container
     runtime. If this is not set, reads from stdin in the container will always
     result in EOF. Default is false.

   args <[]string>
     Arguments to the entrypoint. The docker image‘s CMD is used if this is not
     provided. Variable references $(VAR_NAME) are expanded using the container‘s
     environment. If a variable cannot be resolved, the reference in the input
     string will be unchanged. The $(VAR_NAME) syntax can be escaped with a
     double $$, ie: $$(VAR_NAME). Escaped references will never be expanded,
     regardless of whether the variable exists or not. Cannot be updated. More
     info:
     http://kubernetes.io/docs/user-guide/containers#containers-and-commands

   env  <[]Object>
     List of environment variables to set in the container. Cannot be updated.

3.3replication controller副本控制器

应用托管在Kubernetes之后,Kubernetes需要保证应用能够持续运行,这是RC的工作内容,它会确保任何时间Kubernetes中都有指定数量的Pod在运行。
在此基础上,RC还提供了一些更高级的特性,比如滚动升级、升级回滚等。

滚动升级是一种平滑过渡的升级方式,通过逐步替换的策略,保证整体系统的稳定,在初始升级的时候就可以及时发现、调整问题,以保证问题影响度不会扩大。Kubernetes中滚动升级的命令如下:
$ kubectl rolling-update myweb -f nginx-rc2.yaml --update-period=10s
  升级开始后,首先依据提供的定义文件创建V2版本的RC,然后每隔10s(--update-period=10s)逐步的增加V2版本的Pod副本数,逐步减少V1版本Pod的副本数。升级完成之后,删除V1版本的RC,保留V2版本的RC,及实现滚动升级。

  升级过程中,发生了错误中途退出时,可以选择继续升级。Kubernetes能够智能的判断升级中断之前的状态,然后紧接着继续执行升级。当然,也可以进行回退,命令如下:
$ kubectl rolling-update myweb myweb2 --update-period=10s --rollback
#1.编辑nginx-rc.yaml
vi  nginx-rc.yaml
apiVersion: v1
kind: ReplicationController
metadata:
  name: myweb
spec:
  replicas: 2
  selector:
    app: myweb
  template:
    metadata:
      labels:
        app: myweb
    spec:
      containers:
      - name: myweb
        image: 10.0.0.11:5000/nginx:1.13
        ports:
        - containerPort: 80

#2.创建rc
[root@k8s-master rc]# kubectl create -f nginx-rc.yaml 
replicationcontroller "myweb" created

#3.查看rc,启动两个pod
[root@k8s-master rc]# kubectl get rc
NAME      DESIRED   CURRENT   READY     AGE
myweb     2         2         2         16s
[root@k8s-master rc]# 
[root@k8s-master rc]# kubectl get pods
NAME          READY     STATUS    RESTARTS   AGE
myweb-5wnfl   1/1       Running   0          1m
myweb-qs10q   1/1       Running   0          1m

#4.删除一个pod,立刻启动一个
[root@k8s-master rc]# kubectl delete pod myweb-5wnfl
pod "myweb-5wnfl" deleted
[root@k8s-master rc]# kubectl get pods
NAME          READY     STATUS         RESTARTS   AGE
myweb-qs10q   1/1       Running        0          2m
myweb-xmphk   0/1       ErrImagePull   0          3s
[root@k8s-master rc]# 
#5.RC与Pod的关联——Label
查看pod的标签----Labels:     app=myweb
[root@k8s-master rc]# kubectl describe pod myweb-xmphk
Name:       myweb-xmphk
Namespace:  default
Node:       k8s-node1/10.0.0.12
Start Time: Wed, 28 Aug 2019 18:44:40 +0800
Labels:     app=myweb
查看rc的标签----app=myweb
[root@k8s-master rc]# kubectl get rc -o wide
NAME      DESIRED   CURRENT   READY     AGE       CONTAINER(S)   IMAGE(S)                    SELECTOR
myweb     2         2         1         4m        myweb          10.0.0.11:5000/nginx:1.13   app=myweb

[root@k8s-master rc]# kubectl get all -o wide
NAME       DESIRED   CURRENT   READY     AGE       CONTAINER(S)   IMAGE(S)                    SELECTOR
rc/myweb   2         2         1         5m        myweb          10.0.0.11:5000/nginx:1.13   app=myweb

NAME             CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE       SELECTOR
svc/kubernetes   10.254.0.1   <none>        443/TCP   4h        <none>

NAME             READY     STATUS             RESTARTS   AGE       IP            NODE
po/myweb-qs10q   1/1       Running            0          5m        172.16.93.2   k8s-master
po/myweb-xmphk   0/1       ImagePullBackOff   0          2m        172.16.79.2   k8s-node1
[root@k8s-master rc]# 

#6.新建一个pod,label修改为myweb,会发现自动删除了一个label为myweb的现有Pod,使得数量保持为2
## 6.1新建一个pod
[root@k8s-master k8s]# kubectl create -f nginx_pod.yaml 
pod "test3" created
## 6.2查看
[root@k8s-master k8s]# kubectl get pods
NAME          READY     STATUS             RESTARTS   AGE
myweb-qs10q   1/1       Running            0          11m
myweb-xmphk   0/1       ImagePullBackOff   0          8m
test3         2/2       Running            0          11s
## 6.3编辑

[root@k8s-master k8s]# kubectl edit pod test3
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: 2019-08-28T10:53:28Z
  labels:
    app: myweb ##这里改为myweb
pod "test3" edited
## 6.4查看,删除了一个AGE较小的pod
[root@k8s-master k8s]# kubectl get pods
NAME          READY     STATUS    RESTARTS   AGE
myweb-qs10q   1/1       Running   0          13m
test3         2/2       Running   0          1m
[root@k8s-master k8s]# kubectl get pods
NAME          READY     STATUS    RESTARTS   AGE
myweb-qs10q   1/1       Running   0          13m
test3         2/2       Running   0          1m
[root@k8s-master k8s]# 

#7.rc的滚动升级
##7.1准备rc.yaml
[root@k8s-master rc]# cp nginx-rc.yaml nginx-rc2.yaml 
[root@k8s-master rc]# sed -i s#myweb#myweb2#g nginx-rc2.yaml 
[root@k8s-master rc]# cat nginx-rc2.yaml 
apiVersion: v1
kind: ReplicationController
metadata:
  name: myweb2
spec:
  replicas: 2
  selector:
    app: myweb2
  template:
    metadata:
      labels:
        app: myweb2
    spec:
      containers:
      - name: myweb2
        image: 10.0.0.11:5000/nginx:1.15
        ports:
        - containerPort: 80
[root@k8s-master rc]# 

##7.2把nginx:1.15版本上传到私有仓库
[root@k8s-master rc]# docker pull nginx:1.15
Trying to pull repository docker.io/library/nginx ... 
1.15: Pulling from docker.io/library/nginx
Digest: sha256:23b4dcdf0d34d4a129755fc6f52e1c6e23bb34ea011b315d87e193033bcd1b68
Status: Downloaded newer image for docker.io/nginx:1.15
[root@k8s-master rc]# 
[root@k8s-master rc]# docker tag docker.io/nginx:1.15 10.0.0.11:5000/nginx:1.15
[root@k8s-master rc]# docker push 10.0.0.11:5000/nginx:1.15
The push refers to a repository [10.0.0.11:5000/nginx]
332fa54c5886: Pushed 
6ba094226eea: Pushed 
6270adb5794c: Pushed 
1.15: digest: sha256:e770165fef9e36b990882a4083d8ccf5e29e469a8609bb6b2e3b47d9510e2c8d size: 948

##7.3开始滚动升级
myweb升级为nginx-rc2.yaml
[root@k8s-master rc]# kubectl rolling-update myweb -f nginx-rc2.yaml --update-period=10s
Created myweb2
Scaling up myweb2 from 0 to 2, scaling down myweb from 2 to 0 (keep 2 pods available, dont exceed 3 pods)
Scaling myweb2 up to 1
Scaling myweb down to 1
Scaling myweb2 up to 2
Scaling myweb down to 0
Update succeeded. Deleting myweb
replicationcontroller "myweb" rolling updated to "myweb2"
[root@k8s-master rc]# 
[root@k8s-master ~]# kubectl get pods
NAME           READY     STATUS        RESTARTS   AGE
myweb2-kbsjh   1/1       Running       0          27s
myweb2-tl7fv   1/1       Running       0          37s
test3          2/2       Terminating   0          21m
[root@k8s-master ~]# 

##7.4回滚
myweb2回滚为nginx-rc.yaml
[root@k8s-master rc]# kubectl rolling-update myweb2 -f nginx-rc.yaml --update-period=10s
Created myweb
Scaling up myweb from 0 to 2, scaling down myweb2 from 2 to 0 (keep 2 pods available, dont exceed 3 pods)
Scaling myweb up to 1
Scaling myweb2 down to 1
Scaling myweb up to 2
Scaling myweb2 down to 0
Update succeeded. Deleting myweb2
replicationcontroller "myweb2" rolling updated to "myweb"
[root@k8s-master rc]# 
[root@k8s-master ~]# kubectl get pods
NAME          READY     STATUS    RESTARTS   AGE
myweb-p40zr   1/1       Running   0          49s
myweb-zrnb4   1/1       Running   0          59s
[root@k8s-master ~]# 

##7.5升级过程中断了
#myweb升级到myweb2过程中断了
[root@k8s-master rc]# kubectl rolling-update myweb -f nginx-rc2.yaml --update-period=30s
Created myweb2
Scaling up myweb2 from 0 to 2, scaling down myweb from 2 to 0 (keep 2 pods available, dot exceed 3 pods)
Scaling myweb2 up to 1
^C
[root@k8s-master rc]# 
#此时myweb有两个,myweb2有一个
[root@k8s-master ~]# kubectl get pods
NAME           READY     STATUS    RESTARTS   AGE
myweb-p40zr    1/1       Running   0          3m
myweb-zrnb4    1/1       Running   0          3m
myweb2-lm7f2   1/1       Running   0          12s
[root@k8s-master ~]# 
#回退,还原回原来的myweb
myweb2 from 1 to 0
[root@k8s-master ~]# kubectl rolling-update myweb myweb2 --update-period=10s --rollback
Setting "myweb" replicas to 2
Continuing update with existing controller myweb.
Scaling up myweb from 2 to 2, scaling down myweb2 from 1 to 0 (keep 2 pods available, dont exceed 3 pods)
Scaling myweb2 down to 0
Update succeeded. Deleting myweb2
replicationcontroller "myweb" rolling updated to "myweb2"
[root@k8s-master ~]# 
[root@k8s-master rc]# kubectl get pods
NAME          READY     STATUS    RESTARTS   AGE
myweb-p40zr   1/1       Running   0          5m
myweb-zrnb4   1/1       Running   0          5m
[root@k8s-master rc]#

3.4sevice

#1.service
由于pod是动态变化的,如果一个pod挂掉了,replication会自动再进行创建,以维持固定数量的pod
所以Pod的ip也是总在变化,不能通过docker的端口映射来实现外部访问容器内的服务。
service是提供了一个固定IP,cluster ip,通过该固定的IP来进行通信

#2.三种IP
#2.1nodeip就是宿主机的IP
#2.2clusterip----10.254.0.1
[root@k8s-master rc]# kubectl get all
NAME       DESIRED   CURRENT   READY     AGE
rc/myweb   2         2         2         23m

NAME             CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
svc/kubernetes   10.254.0.1   <none>        443/TCP   5h

NAME             READY     STATUS    RESTARTS   AGE
po/myweb-p40zr   1/1       Running   0          23m
po/myweb-zrnb4   1/1       Running   0          23m
[root@k8s-master rc]# 

#2.3podip就是pod的ip
[root@k8s-master rc]# kubectl get all -o wide
NAME       DESIRED   CURRENT   READY     AGE       CONTAINER(S)   IMAGE(S)                    SELECTOR
rc/myweb   2         2         2         28m       myweb          10.0.0.11:5000/nginx:1.13   app=myweb

NAME             CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE       SELECTOR
svc/kubernetes   10.254.0.1   <none>        443/TCP   5h        <none>

NAME             READY     STATUS    RESTARTS   AGE       IP            NODE
po/myweb-p40zr   1/1       Running   0          28m       172.16.79.3   k8s-node1
po/myweb-zrnb4   1/1       Running   0          28m       172.16.48.2   k8s-node2
[root@k8s-master rc]# 

#3.创建service
vi nginx-svc.yaml
apiVersion: v1
kind: Service
metadata:
  name: myweb
spec:
  type: NodePort
  ports:
    - port: 80
      nodePort: 30000
      targetPort: 80
  selector:
    app: myweb
[root@k8s-master svc]# kubectl create -f nginx-svc.yaml 
service "myweb" created
[root@k8s-master svc]# kubectl describe svc myweb
Name:           myweb
Namespace:      default
Labels:         <none>
Selector:       app=myweb
Type:           NodePort
IP:         10.254.6.89
Port:           <unset> 80/TCP
NodePort:       <unset> 30000/TCP
Endpoints:      172.16.48.2:80,172.16.79.3:80
Session Affinity:   None
No events.
[root@k8s-master svc]#
[root@k8s-master svc]# kubectl get pod -o wide
NAME          READY     STATUS    RESTARTS   AGE       IP            NODE
myweb-p40zr   1/1       Running   0          50m       172.16.79.3   k8s-node1
myweb-zrnb4   1/1       Running   0          50m       172.16.48.2   k8s-node2
[root@k8s-master svc]# 

#4.访问,以下地址都可访问到
是由kuber-proxy服务提供的
http://10.0.0.11:30000/
http://10.0.0.12:30000/
http://10.0.0.13:30000/

技术图片


#5.service服务的自动发现
[root@k8s-master svc]# kubectl scale rc myweb --replicas=3
replicationcontroller "myweb" scaled
[root@k8s-master svc]# kubctl get pod -o wide
-bash: kubctl: command not found
[root@k8s-master svc]# kubectl get pod -o wide
NAME          READY     STATUS    RESTARTS   AGE       IP            NODE
myweb-p40zr   1/1       Running   0          51m       172.16.79.3   k8s-node1
myweb-q5wrj   1/1       Running   0          16s       172.16.93.2   k8s-master
myweb-zrnb4   1/1       Running   0          51m       172.16.48.2   k8s-node2
[root@k8s-master svc]# kubectl describe svc myweb
Name:           myweb
Namespace:      default
Labels:         <none>
Selector:       app=myweb
Type:           NodePort
IP:         10.254.6.89
Port:           <unset> 80/TCP
NodePort:       <unset> 30000/TCP
Endpoints:      172.16.48.2:80,172.16.79.3:80,172.16.93.2:80
Session Affinity:   None
No events.
[root@k8s-master svc]# 
[root@k8s-master svc]# kubectl get svc
NAME         CLUSTER-IP    EXTERNAL-IP   PORT(S)        AGE
kubernetes   10.254.0.1    <none>        443/TCP        5h
myweb        10.254.6.89   <nodes>       80:30000/TCP   9m

#6.service服务的负载均衡

[root@k8s-master svc]# kubectl get pods
NAME          READY     STATUS    RESTARTS   AGE
myweb-p40zr   1/1       Running   0          1h
myweb-q5wrj   1/1       Running   0          11m
myweb-zrnb4   1/1       Running   0          1h
[root@k8s-master svc]# echo pod1>index.html
[root@k8s-master svc]# kubectl cp index.html myweb-p40zr:/usr/share/nginx/html/index.html
/etc/hosts一定要做主机名解析,否则报错
[root@k8s-master svc]# kubectl cp index.html myweb-q5wrj:/usr/share/nginx/html/index.html
Error from server: error dialing backend: dial tcp: lookup k8s-master on 223.5.5.5:53: no such host

[root@k8s-master svc]# echo pod2>index.html
[root@k8s-master svc]# kubectl cp index.html myweb-q5wrj:/usr/share/nginx/html/index.html
[root@k8s-master svc]# echo pod3>index.html
[root@k8s-master svc]# kubectl cp index.html myweb-zrnb4:/usr/share/nginx/html/index.html
[root@k8s-master svc]# 
会持续一段时间
[root@k8s-master svc]# curl 10.0.0.12:30000
pod1
[root@k8s-master svc]# curl 10.0.0.12:30000
pod3
[root@k8s-master svc]# curl 10.0.0.12:30000
pod1
[root@k8s-master svc]# curl 10.0.0.12:30000
pod3
[root@k8s-master svc]# curl 10.0.0.12:30000
pod1
[root@k8s-master svc]# curl 10.0.0.12:30000
pod2
[root@k8s-master svc]# 

#7. nodePort端口范围默认是30000-32767
##7.1修改默认端口范围
[root@k8s-master svc]# vim /etc/kubernetes/apiserver

KUBE_API_ARGS="--service-node-port-range=10000-60000"
[root@k8s-master svc]# systemctl restart kube-apiserver.service
#启动参数应用处
[root@k8s-master svc]# cat /usr/lib/systemd/system/kube-apiserver.service 
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target
After=etcd.service

[Service]
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/apiserver
User=kube
ExecStart=/usr/bin/kube-apiserver         $KUBE_LOGTOSTDERR         $KUBE_LOG_LEVEL         $KUBE_ETCD_SERVERS         $KUBE_API_ADDRESS         $KUBE_API_PORT         $KUBELET_PORT         $KUBE_ALLOW_PRIV         $KUBE_SERVICE_ADDRESSES         $KUBE_ADMISSION_CONTROL         $KUBE_API_ARGS
Restart=on-failure
Type=notify
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
[root@k8s-master svc]#
##7.2修改端口为10000试一下
[root@k8s-master svc]# cat nginx-svc.yaml
apiVersion: v1
kind: Service
metadata:
  name: myweb
spec:
  type: NodePort
  ports:
    - port: 80
      nodePort: 10000
      targetPort: 80
  selector:
    app: myweb

[root@k8s-master svc]# kubectl apply -f nginx-svc.yaml 
service "myweb" configured
[root@k8s-master svc]# 
[root@k8s-master svc]# kubectl describe svc myweb
Name:           myweb
Namespace:      default
Labels:         <none>
Selector:       app=myweb
Type:           NodePort
IP:         10.254.6.89
Port:           <unset> 80/TCP
NodePort:       <unset> 10000/TCP
Endpoints:      172.16.48.2:80,172.16.79.3:80,172.16.93.2:80
Session Affinity:   None
No events.
[root@k8s-master svc]# 
[root@k8s-master svc]# curl 10.0.0.12:10000
pod2
[root@k8s-master svc]# curl 10.0.0.12:10000
pod3
[root@k8s-master svc]# curl 10.0.0.12:10000
pod1
[root@k8s-master svc]# 
##7.3cluster ip地址范围指定处
[root@k8s-master svc]# cat /etc/kubernetes/apiserver
# Address range to use for services
KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16"

28.kubernetes

标签:flannel   影响   pass   加速   mode   pack   within   exe   节点配置   

原文地址:https://blog.51cto.com/10983441/2433436

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