28.kubernetes
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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
1.3k8s核心组件和架构
2.安装
2.1环境准备
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 tcpdump2.2-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.containersnginx 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.containersnginx Normal Pulled Successfully pulled image "nginx:1.13"
2m 2m 1 kubelet k8s-node2 spec.containersnginx Normal Created Created container with docker id fcdfa71abdb5; Security:[seccomp=unconfined]
2m 2m 1 kubelet k8s-node2 spec.containersnginx 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.containersnginx 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.containersnginx 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.containersnginx 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.containersnginx Normal Pulled Successfully pulled image "nginx:1.13"
1m 1m 1 kubelet k8s-node1 spec.containersnginx Normal Created Created container with docker id 13374ea68659; Security:[seccomp=unconfined]
1m 1m 1 kubelet k8s-node1 spec.containersnginx 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.containersnginx Normal Pulled Container image "10.0.0.11:5000/nginx:1.13" already present on machine
2m 2m 1 kubelet k8s-node2 spec.containersnginx Normal Created Created container with docker id 964ab40f1fdf; Security:[seccomp=unconfined]
2m 2m 1 kubelet k8s-node2 spec.containersnginx 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/
#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"
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