k8s集群二进制部署过程
1.部署ETCd集群
下载cfssl工具：
wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
chmod +x cfssl_linux-amd64 cfssljson_linux-amd64 cfssl-certinfo_linux-amd64
mv cfssl_linux-amd64 /usr/local/bin/cfssl
mv cfssljson_linux-amd64 /usr/local/bin/cfssljson
mv cfssl-certinfo_linux-amd64 /usr/bin/cfssl-certinfo
生成Etcd证书:
创建以下三个文件：
vim ca-config.json
{
"signing": {
"default": {
"expiry": "87600h"
},
"profiles": {
"www": {
"expiry": "87600h",
"usages": [
"signing",
"key encipherment",
"server auth",
"client auth"
]
}
}
}
}
vim ca-csr.json
{
"CN": "etcd CA",
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "Beijing",
"ST": "Beijing"
}
]
}
修改etcd集群的主机IP地址
vim server-csr.json
{
"CN": "etcd",
"hosts": [
"192.168.135.128",
"192.168.135.129",
"192.168.135.130"
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "BeiJing",
"ST": "BeiJing"
}
]
}
>生成证书：
# cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=www server-csr.json | cfssljson -bare server
# ls *pem
ca-key.pem ca.pem server-key.pem server.pem
>安装Etcd:
二进制包下载地址：
https://github.com/coreos/etcd/releases/tag/v3.2.12
wget https://github.com/etcd-io/etcd/releases/download/v3.2.12/etcd-v3.2.12-linux-amd64.tar.gz
>以下部署步骤在规划的三个etcd节点操作一样，唯一不同的是etcd配置文件中的服务器IP要写当前的：
解压二进制包：
mkdir /opt/etcd/{bin,cfg,ssl} -p
tar zxvf etcd-v3.2.12-linux-amd64.tar.gz
mv etcd-v3.2.12-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/
创建etcd配置文件：
cat >> /opt/etcd/cfg/etcd >systemd管理etcd：
vim /usr/lib/systemd/system/etcd.service
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target
[Service]
Type=notify
EnvironmentFile=/opt/etcd/cfg/etcd
ExecStart=/opt/etcd/bin/etcd \
--name=${ETCD_NAME} \
--data-dir=${ETCD_DATA_DIR} \
--listen-peer-urls=${ETCD_LISTEN_PEER_URLS} \
--listen-client-urls=${ETCD_LISTEN_CLIENT_URLS},http://127.0.0.1:2379 \
--advertise-client-urls=${ETCD_ADVERTISE_CLIENT_URLS} \
--initial-advertise-peer-urls=${ETCD_INITIAL_ADVERTISE_PEER_URLS} \
--initial-cluster=${ETCD_INITIAL_CLUSTER} \
--initial-cluster-token=${ETCD_INITIAL_CLUSTER_TOKEN} \
--initial-cluster-state=new \
--cert-file=/opt/etcd/ssl/server.pem \
--key-file=/opt/etcd/ssl/server-key.pem \
--peer-cert-file=/opt/etcd/ssl/server.pem \
--peer-key-file=/opt/etcd/ssl/server-key.pem \
--trusted-ca-file=/opt/etcd/ssl/ca.pem \
--peer-trusted-ca-file=/opt/etcd/ssl/ca.pem
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
>把刚才生成的证书拷贝到配置文件中的位置：
# cp ca*pem server*pem /opt/etcd/ssl
>启动并设置开启启动：
# systemctl start etcd
# systemctl enable etcd
>都部署完成后，检查etcd集群状态：
# /opt/etcd/bin/etcdctl \
--ca-file=/opt/etcd/ssl/ca.pem --cert-file=/opt/etcd/ssl/server.pem --key-file=/opt/etcd/ssl/server-key.pem \
--endpoints="https://192.168.135.128:2379,https://192.168.135.129:2379,https://192.168.135.130:2379" \
cluster-health
member 4101e54b63ca7b19 is healthy: got healthy result from https://192.168.135.129:2379
member 5a58f66f830ba739 is healthy: got healthy result from https://192.168.135.128:2379
member 67e264f60acc1d51 is healthy: got healthy result from https://192.168.135.130:2379
cluster is healthy
>如果输出上面信息，就说明集群部署成功。
-------------------------------------------在Node节点安装Docker----------------------------------------------------------
yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager \
--add-repo \
https://download.docker.com/linux/centos/docker-ce.repo
yum install docker-ce -y
curl -sSL https://get.daocloud.io/daotools/set_mirror.sh | sh -s http://bc437cce.m.daocloud.io
systemctl start docker
systemctl enable docker
-------------------------------------------部署Flannel网络----------------------------------------------------------
>Falnnel要用etcd存储自身一个子网信息，所以要保证能成功连接Etcd，写入预定义子网段：
# /opt/etcd/bin/etcdctl \
--ca-file=ca.pem --cert-file=server.pem --key-file=server-key.pem \
--endpoints="https://192.168.135.128:2379,https://192.168.135.129:2379,https://192.168.135.130:2379" \
set /coreos.com/network/config '{ "Network": "172.17.0.0/16", "Backend": {"Type": "vxlan"}}'
>以下部署步骤在规划的每个node节点都操作。
下载二进制包：
wget https://github.com/coreos/flannel/releases/download/v0.10.0/flannel-v0.10.0-linux-amd64.tar.gz
tar zxvf flannel-v0.10.0-linux-amd64.tar.gz
mkdir -pv /opt/kubernetes/bin
mv flanneld mk-docker-opts.sh /opt/kubernetes/bin
>配置Flannel：
# mkdir -pv /opt/kubernetes/cfg/
# vim /opt/kubernetes/cfg/flanneld
FLANNEL_OPTIONS="--etcd-endpoints=https://192.168.135.128:2379,https://192.168.135.129:2379,https://192.168.135.130:2379 -etcd-cafile=/opt/etcd/ssl/ca.pem -etcd-certfile=/opt/etcd/ssl/server.pem -etcd-keyfile=/opt/etcd/ssl/server-key.pem"
>systemd管理Flannel：
# cat >> /usr/lib/systemd/system/flanneld.service >配置Docker启动指定子网段：
cat >> /usr/lib/systemd/system/docker.service 从其他节点拷贝证书文件到node1和2上：因为node1和2上没有证书，但是flanel需要证书
mkdir -pv /opt/etcd/ssl/
scp /opt/etcd/ssl/* k8s-node2:/opt/etcd/ssl/
重启flannel和docker：
systemctl daemon-reload
systemctl start flanneld
systemctl enable flanneld
systemctl restart docker
检查是否生效：
ps -ef |grep docker
root 20941 1 1 Jun28 ? 09:15:34 /usr/bin/dockerd --bip=172.17.34.1/24 --ip-masq=false --mtu=1450
ip addr
3607: flannel.1: mtu 1450 qdisc noqueue state UNKNOWN
link/ether 8a:2e:3d:09:dd:82 brd ff:ff:ff:ff:ff:ff
inet 172.17.34.0/32 scope global flannel.1
valid_lft forever preferred_lft forever
3608: docker0: mtu 1450 qdisc noqueue state UP
link/ether 02:42:31:8f:d3:02 brd ff:ff:ff:ff:ff:ff
inet 172.17.34.1/24 brd 172.17.34.255 scope global docker0
valid_lft forever preferred_lft forever
inet6 fe80::42:31ff:fe8f:d302/64 scope link
valid_lft forever preferred_lft forever
>确保docker0与flannel.1在同一网段。
测试不同节点互通，在当前节点访问另一个Node节点docker0 IP：
# ping 172.17.58.1
PING 172.17.58.1 (172.17.58.1) 56(84) bytes of data.
64 bytes from 172.17.58.1: icmp_seq=1 ttl=64 time=0.263 ms
64 bytes from 172.17.58.1: icmp_seq=2 ttl=64 time=0.204 ms
如果能通说明Flannel部署成功。如果不通检查下日志：journalctl -u flannel
>在Master节点部署组件:
两个Master节点部署方式一样
在部署Kubernetes之前一定要确保etcd、flannel、docker是正常工作的，否则先解决问题再继续。
>生成证书
创建CA证书：
cat >> ca-config.json < EOF
{
"signing": {
"default": {
"expiry": "87600h"
},
"profiles": {
"kubernetes": {
"expiry": "87600h",
"usages": [
"signing",
"key encipherment",
"server auth",
"client auth"
]
}
}
}
}
EOF
cat >> ca-csr.json < EOF
{
"CN": "kubernetes",
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "Beijing",
"ST": "Beijing",
"O": "k8s",
"OU": "System"
}
]
}
EOF
cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
生成apiserver证书：
cat >> server-csr.json < EOF
{
"CN": "kubernetes",
"hosts": [
"10.0.0.1",//这是后面dns要使用的虚拟网络的网关，不用改，就用这个 切忌(删除这行)
"127.0.0.1",
"192.168.135.128",
"192.168.135.129",
"195.168.135.130",
"kubernetes",
"kubernetes.default",
"kubernetes.default.svc",
"kubernetes.default.svc.cluster",
"kubernetes.default.svc.cluster.local"
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "BeiJing",
"ST": "BeiJing",
"O": "k8s",
"OU": "System"
}
]
}
EOF
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes server-csr.json | cfssljson -bare server
生成kube-proxy证书：
cat >> kube-proxy-csr.json < EOF
{
"CN": "system:kube-proxy",
"hosts": [],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "BeiJing",
"ST": "BeiJing",
"O": "k8s",
"OU": "System"
}
]
}
EOF
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy
>最终生成以下证书文件：
# ls *pem
ca-key.pem ca.pem kube-proxy-key.pem kube-proxy.pem server-key.pem server.pem
>部署apiserver组件
下载二进制包：
https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.11.md 下载这个包（kubernetes-server-linux-amd64.tar.gz）就够了，包含了所需的所有组件。
wget https://dl.k8s.io/v1.11.10/kubernetes-server-linux-amd64.tar.gz
mkdir /opt/kubernetes/{bin,cfg,ssl} -pv
tar zxvf kubernetes-server-linux-amd64.tar.gz
cd kubernetes/server/bin
cp kube-apiserver kube-scheduler kube-controller-manager kubectl /opt/kubernetes/bin
>从生成证书的机器拷贝证书到master1,master2:
scp server.pem server-key.pem ca.pem ca-key.pem k8s-master1:/opt/kubernetes/ssl/
scp server.pem server-key.pem ca.pem ca-key.pem k8s-master2:/opt/kubernetes/ssl/
>创建token文件
cat >> /opt/kubernetes/cfg/token.csv >创建apiserver配置文件：
cat >> /opt/kubernetes/cfg/kube-apiserver < EOF
KUBE_APISERVER_OPTS="--logtostderr=true \
--v=4 \
--etcd-servers=https://192.168.135.128:2379,https://192.168.135.129:2379,https://192.168.135.130:2379 \
--bind-address=192.168.135.128 \
--secure-port=6443 \
--advertise-address=192.168.135.128 \
--allow-privileged=true \
--service-cluster-ip-range=10.0.0.0/24 \
--enable-admission-plugins=NamespaceLifecycle,LimitRanger,ServiceAccount,ResourceQuota,NodeRestriction \
--authorization-mode=RBAC,Node \
--enable-bootstrap-token-auth \
--token-auth-file=/opt/kubernetes/cfg/token.csv \
--service-node-port-range=30000-50000 \
--tls-cert-file=/opt/kubernetes/ssl/server.pem \
--tls-private-key-file=/opt/kubernetes/ssl/server-key.pem \
--client-ca-file=/opt/kubernetes/ssl/ca.pem \
--service-account-key-file=/opt/kubernetes/ssl/ca-key.pem \
--etcd-cafile=/opt/etcd/ssl/ca.pem \
--etcd-certfile=/opt/etcd/ssl/server.pem \
--etcd-keyfile=/opt/etcd/ssl/server-key.pem"
EOF
配置好前面生成的证书，确保能连接etcd。
参数说明：
* --logtostderr 启用日志
* --v 日志等级
* --etcd-servers etcd集群地址
* --bind-address 监听地址
* --secure-port https安全端口
* --advertise-address 集群通告地址
* --allow-privileged 启用授权
* --service-cluster-ip-range Service虚拟IP地址段
* --enable-admission-plugins 准入控制模块
* --authorization-mode 认证授权，启用RBAC授权和节点自管理
* --enable-bootstrap-token-auth 启用TLS bootstrap功能，后面会讲到
* --token-auth-file token文件
* --service-node-port-range Service Node类型默认分配端口范围
>systemd管理apiserver：
cat >> /usr/lib/systemd/system/kube-apiserver.service < EOF
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=-/opt/kubernetes/cfg/kube-apiserver
ExecStart=/opt/kubernetes/bin/kube-apiserver $KUBE_APISERVER_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF
启动：
systemctl daemon-reload
systemctl enable kube-apiserver
systemctl start kube-apiserver
>部署schduler组件创建schduler配置文件
cat > /opt/kubernetes/cfg/kube-scheduler < EOF
KUBE_SCHEDULER_OPTS="--logtostderr=true \
--v=4 \
--master=127.0.0.1:8080 \
--leader-elect"
EOF
参数说明：
* --master 连接本地apiserver
* --leader-elect 当该组件启动多个时，自动选举（HA）
>systemd管理schduler组件：
cat > /usr/lib/systemd/system/kube-scheduler.service < EOF
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=-/opt/kubernetes/cfg/kube-scheduler
ExecStart=/opt/kubernetes/bin/kube-scheduler $KUBE_SCHEDULER_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF
启动：
systemctl daemon-reload
systemctl enable kube-scheduler
systemctl start kube-scheduler
>部署controller-manager组件
创建controller-manager配置文件：
cat > /opt/kubernetes/cfg/kube-controller-manager < EOF
KUBE_CONTROLLER_MANAGER_OPTS="--logtostderr=true \
--v=4 \
--master=127.0.0.1:8080 \
--leader-elect=true \
--address=127.0.0.1 \
--service-cluster-ip-range=10.0.0.0/24 \
--cluster-name=kubernetes \
--cluster-signing-cert-file=/opt/kubernetes/ssl/ca.pem \
--cluster-signing-key-file=/opt/kubernetes/ssl/ca-key.pem \
--root-ca-file=/opt/kubernetes/ssl/ca.pem \
--service-account-private-key-file=/opt/kubernetes/ssl/ca-key.pem"
EOF
>systemd管理controller-manager组件：
cat > /usr/lib/systemd/system/kube-controller-manager.service < EOF
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=-/opt/kubernetes/cfg/kube-controller-manager
ExecStart=/opt/kubernetes/bin/kube-controller-manager $KUBE_CONTROLLER_MANAGER_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF
启动：
systemctl daemon-reload
systemctl enable kube-controller-manager
systemctl start kube-controller-manager
所有组件都已经启动成功，通过kubectl工具查看当前集群组件状态：
ln -s /opt/kubernetes/bin/kubectl /usr/bin/
kubectl get cs
NAME STATUS MESSAGE ERROR
scheduler Healthy ok
etcd-0 Healthy {"health":"true"}
etcd-2 Healthy {"health":"true"}
etcd-1 Healthy {"health":"true"}
controller-manager Healthy ok
如上输出说明组件都正常。
-----------------------------------下面这些操作在master节点完成：--------------------------------------------
将kubelet-bootstrap用户绑定到系统集群角色
/opt/kubernetes/bin/kubectl create clusterrolebinding kubelet-bootstrap \
--clusterrole=system:node-bootstrapper \
--user=kubelet-bootstrap
>创建kubeconfig文件:
在生成kubernetes证书的目录下执行以下命令生成kubeconfig文件：
指定apiserver 地址(如果apiserver做了负载均衡，则填写负载均衡地址)
KUBE_APISERVER="https://192.168.135.128:6443"
BOOTSTRAP_TOKEN=674c457d4dcf2eefe4920d7dbb6b0ddc
设置集群参数
/opt/kubernetes/bin/kubectl config set-cluster kubernetes \
--certificate-authority=./ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=bootstrap.kubeconfig
设置客户端认证参数
/opt/kubernetes/bin/kubectl config set-credentials kubelet-bootstrap \
--token=${BOOTSTRAP_TOKEN} \
--kubeconfig=bootstrap.kubeconfig
设置上下文参数
/opt/kubernetes/bin/kubectl config set-context default \
--cluster=kubernetes \
--user=kubelet-bootstrap \
--kubeconfig=bootstrap.kubeconfig
设置默认上下文
/opt/kubernetes/bin/kubectl config use-context default --kubeconfig=bootstrap.kubeconfig
#----------------------
>创建kube-proxy kubeconfig文件
/opt/kubernetes/bin/kubectl config set-cluster kubernetes \
--certificate-authority=./ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=kube-proxy.kubeconfig
/opt/kubernetes/bin/kubectl config set-credentials kube-proxy \
--client-certificate=./kube-proxy.pem \
--client-key=./kube-proxy-key.pem \
--embed-certs=true \
--kubeconfig=kube-proxy.kubeconfig
/opt/kubernetes/bin/kubectl config set-context default \
--cluster=kubernetes \
--user=kube-proxy \
--kubeconfig=kube-proxy.kubeconfig
/opt/kubernetes/bin/kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig
# ls
bootstrap.kubeconfig kube-proxy.kubeconfig
坑：将这两个文件拷贝到Node节点/opt/kubernetes/cfg目录下。
----------------------下面这些操作在node节点完成：---------------------------
部署kubelet组件
将前面下载的二进制包中的kubelet和kube-proxy拷贝到/opt/kubernetes/bin目录下。
创建kubelet配置文件：
cat > /opt/kubernetes/cfg/kubelet < EOF
KUBELET_OPTS="--logtostderr=true \
--v=4 \
--hostname-override=192.168.135.129 \
--kubeconfig=/opt/kubernetes/cfg/kubelet.kubeconfig \
--bootstrap-kubeconfig=/opt/kubernetes/cfg/bootstrap.kubeconfig \
--config=/opt/kubernetes/cfg/kubelet.config \
--cert-dir=/opt/kubernetes/ssl \
--pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google-containers/pause-amd64:3.0"
EOF
参数说明：
* --hostname-override 在集群中显示的主机名
* --kubeconfig 指定kubeconfig文件位置，会自动生成
* --bootstrap-kubeconfig 指定刚才生成的bootstrap.kubeconfig文件
* --cert-dir 颁发证书存放位置
* --pod-infra-container-image 管理Pod网络的镜像
其中/opt/kubernetes/cfg/kubelet.config配置文件如下：
cat > /opt/kubernetes/cfg/kubelet.config < EOF
kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
address: 192.168.135.129
port: 10250
readOnlyPort: 10255
cgroupDriver: cgroupfs
clusterDNS: ["10.0.0.2"]
clusterDomain: cluster.local.
failSwapOn: false
authentication:
anonymous:
enabled: true
webhook:
enabled: false
EOF
>systemd管理kubelet组件：
cat > /usr/lib/systemd/system/kubelet.service < EOF
[Unit]
Description=Kubernetes Kubelet
After=docker.service
Requires=docker.service
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kubelet
ExecStart=/opt/kubernetes/bin/kubelet $KUBELET_OPTS
Restart=on-failure
KillMode=process
[Install]
WantedBy=multi-user.target
EOF
>启动：
systemctl daemon-reload
systemctl enable kubelet
systemctl start kubelet
>在Master审批Node加入集群：
启动后还没加入到集群中，需要手动允许该节点才可以。在Master节点查看请求签名的Node：
/opt/kubernetes/bin/kubectl get csr
/opt/kubernetes/bin/kubectl certificate approve XXXXID
/opt/kubernetes/bin/kubectl get node
>部署kube-proxy组件
创建kube-proxy配置文件：
cat > /opt/kubernetes/cfg/kube-proxy < EOF
KUBE_PROXY_OPTS="--logtostderr=true \
--v=4 \
--hostname-override=192.168.135.129 \
--cluster-cidr=10.0.0.0/24 \ //不要改，就是这个ip
--kubeconfig=/opt/kubernetes/cfg/kube-proxy.kubeconfig"
EOF
>systemd管理kube-proxy组件：
cat > /usr/lib/systemd/system/kube-proxy.service < EOF
[Unit]
Description=Kubernetes Proxy
After=network.target
[Service]
EnvironmentFile=-/opt/kubernetes/cfg/kube-proxy
ExecStart=/opt/kubernetes/bin/kube-proxy $KUBE_PROXY_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF
>启动：
systemctl daemon-reload
systemctl enable kube-proxy
systemctl start kube-proxy
>查看集群状态
# /opt/kubernetes/bin/kubectl get node
NAME STATUS ROLES AGE VERSION
10.206.240.111 Ready 28d v1.11.0
10.206.240.112 Ready 28d v1.11.0
# /opt/kubernetes/bin/kubectl get cs
NAME STATUS MESSAGE ERROR
controller-manager Healthy ok
scheduler Healthy ok
etcd-2 Healthy {"health":"true"}
etcd-1 Healthy {"health":"true"}
etcd-0 Healthy {"health":"true"}
>运行一个测试示例
创建一个Nginx Web，判断集群是否正常工作：
# /opt/kubernetes/bin/kubectl run nginx --image=nginx --replicas=3
# /opt/kubernetes/bin/kubectl expose deployment nginx --port=88 --target-port=80 --type=NodePort
查看Pod，Service：
# /opt/kubernetes/bin/kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-64f497f8fd-fjgt2 1/1 Running 3 28d
nginx-64f497f8fd-gmstq 1/1 Running 3 28d
nginx-64f497f8fd-q6wk9 1/1 Running 3 28d
>查看pod详细信息：
# /opt/kubernetes/bin/kubectl describe nginx-64f497f8fd-fjgt2
# /opt/kubernetes/bin/kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.0.0.1 443/TCP 28d
nginx NodePort 10.0.0.175 88:38696/TCP 28d
>打开浏览器输入：http://10.206.240.111:38696
编写yaml文件内容如下：
---
apiVersion: v1
kind: Pod
metadata:
name: kube100-site
labels:
app: web
app1: abc234 //labels里面标签的值不能是纯数字
spec:
containers:
- name: front-end
image: daocloud.io/library/nginx
ports:
- containerPort: 80
>创建Pod：
# kubectl apply -f pod.yaml
pod "kube100-site" created
>查看pod状态
通过get命令来查看被创建的pod。
如果执行完创建pod的命令之后，你的速度足够快，那么使用get命令你将会看到以下的状态：
# kubectl get pods
NAME READY STATUS RESTARTS AGE
hello-world 0/1 Pending 0 0s
# kubectl get pods
NAME READY STATUS RESTARTS AGE
kube100-site 2/2 Running 0 1m
注： Pod创建过程中如果出现错误，可以使用kubectl describe 进行排查。
各字段含义：
NAME: Pod的名称
READY: Pod的准备状况，右边的数字表示Pod包含的容器总数目，左边的数字表示准备就绪的容器数目。
STATUS: Pod的状态。
RESTARTS: Pod的重启次数
AGE: Pod的运行时间。
pod的准备状况指的是Pod是否准备就绪以接收请求，Pod的准备状况取决于容器，即所有容器都准备就绪了，Pod才准备就绪。这时候kubernetes的代理服务才会添加Pod作为分发后端，而一旦Pod的准备状况变为false(至少一个容器的准备状况为false),kubernetes会将Pod从代理服务的分发后端移除，即不会分发请求给该Pod。
一个pod刚被创建的时候是不会被调度的，因为没有任何节点被选择用来运行这个pod。调度的过程发生在创建完成之后，但是这个过程一般很快，所以你通常看不到pod是处于unscheduler状态的除非创建的过程遇到了问题。
pod被调度之后，分配到指定的节点上运行，这时候，如果该节点没有所需要的image，那么将会自动从默认的Docker Hub上pull指定的image，一切就绪之后，看到pod是处于running状态了：
# kubectl get pods
NAME READY STATUS RESTARTS AGE
my-nginx-379829228-2zjv3 1/1 Running 0 1h
my-nginx-379829228-mm8f8 1/1 Running 0 1h
查看pods所在的运行节点：
# kubectl get pods -o wide
查看pods定义的详细信息：
# kubectl get pods -o yaml
# kubectl get pod nginx-8v3cg --output yaml
kubectl get支持以Go Template方式过滤指定的信息，比如查询Pod的运行状态
# kubectl get pods busybox --output=go-template --template={{.status.phase}}
Running
查看pod输出：
你可能会有想了解在pod中执行命令的输出是什么，和Docker logs命令一样，kubectl logs将会显示这些输出：
#kubectl logs pod名称
hello world
查看kubectl describe 支持查询Pod的状态和生命周期事件：
[root@k8s-master ~]# kubectl describe pod busybox
Name: busybox
Namespace: default
Node: k8s-node-1/116.196.105.133
Start Time: Thu, 22 Mar 2018 09:51:35 +0800
Labels: name=busybox
role=master
Status: Pending
IP:
Controllers:
Containers:
busybox:
Container ID:
Image: docker.io/busybox
Image ID:
Port:
Command:
sleep
360000
State: Waiting
Reason: ContainerCreating
Ready: False
Restart Count: 0
Volume Mounts:
Environment Variables:
Conditions:
Type Status
Initialized True
Ready False
PodScheduled True
No volumes.
QoS Class: BestEffort
Tolerations:
Events:
FirstSeen LastSeen Count From SubObjectPath Type Reason Message
--------- -------- ----- ---- ------------- -------- ------ -------
7m 7m 1 {default-scheduler } Normal Scheduled Successfully assigne
d busybox to k8s-node-1 7m 1m 6 {kubelet k8s-node-1} Warning FailedSync Error syncing pod, s
kipping: 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)"
6m 13s 27 {kubelet k8s-node-1} Warning FailedSync Error syncing pod, skipping: failed to "StartContain
er" for "POD" with ImagePullBackOff: "Back-off pulling image \"registry.access.redhat.com/rhel7/pod-infrastructure:latest\""
各字段含义：
Name: Pod的名称
Namespace: Pod的Namespace。
Image(s): Pod使用的镜像
Node: Pod所在的Node。
Start Time: Pod的起始时间
Labels: Pod的Label。
Status: Pod的状态。
Reason: Pod处于当前状态的原因。
Message: Pod处于当前状态的信息。
IP: Pod的PodIP
Replication Controllers: Pod对应的Replication Controller。
Containers:Pod中容器的信息
Container ID: 容器的ID
Image: 容器的镜像
Image ID:镜像的ID
State: 容器的状态
Ready: 容器的准备状况(true表示准备就绪)。
Restart Count: 容器的重启次数统计
Environment Variables: 容器的环境变量
Conditions: Pod的条件，包含Pod准备状况(true表示准备就绪)
Volumes: Pod的数据卷
Events: 与Pod相关的事件列表
进入Pod对应的容器内部
[root@k8s-master /]# kubectl exec -it myweb-76h6w /bin/bash
删除pod：
# kubectl delete pod pod名1 pod名2 //单个或多个删除
# kubectl delete pod --all //批量删除
例：
[root@k8s-master /]# kubectl delete pod hello-world
pod "hello-world" deleted
重新启动基于yaml文件的应用
kubectl delete -f XXX.yaml
kubectl apply -f XXX.yaml
常用命令
kubectl get pods
kubectl get pods -o wide
/opt/kubernetes/bin/kubectl get svc
/opt/kubernetes/bin/kubectl get cs
/opt/kubernetes/bin/kubectl get pods
kubectl apply -f pod.yaml
kubectl logs pod名称
kubectl describe pod busybox
kubectl delete pod pod名1 pod名2
kubectl delete -f XXX.yaml
kubectl apply -f XXX.yaml
kubectl exec -it myweb-76h6w /bin/bash