部署高可用 schduler
目录
创建 kube-scheduler 证书和私钥
创建证书签名请求:
cd /opt/k8s/work
cat > kube-scheduler-csr.json <<EOF
{
"CN": "system:kube-scheduler",
"hosts": [
"127.0.0.1",
"10.0.20.11",
"10.0.20.12",
"10.0.20.13",
"node01.k8s.com",
"node02.k8s.com",
"node03.k8s.com"
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "system:kube-scheduler",
"OU": "4Paradigm"
}
]
}
EOF
- hosts 列表包含所有 kube-scheduler 节点 IP;
- CN 和 O 均为 system:kube-scheduler,kubernetes 内置的 ClusterRoleBindings system:kube-scheduler 将赋予 kube-scheduler 工作所需的权限;
生成证书和私钥:
cd /opt/k8s/work
cfssl gencert -ca=/opt/k8s/work/ca.pem \
-ca-key=/opt/k8s/work/ca-key.pem \
-config=/opt/k8s/work/ca-config.json \
-profile=kubernetes kube-scheduler-csr.json | cfssljson -bare kube-scheduler
ls kube-scheduler*pem
将生成的证书和私钥分发到所有 master 节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-scheduler*.pem root@${node_ip}:/etc/kubernetes/cert/
done
创建和分发 kubeconfig 文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
kubectl config set-cluster kubernetes \
--certificate-authority=/opt/k8s/work/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=kube-scheduler.kubeconfig
kubectl config set-credentials system:kube-scheduler \
--client-certificate=kube-scheduler.pem \
--client-key=kube-scheduler-key.pem \
--embed-certs=true \
--kubeconfig=kube-scheduler.kubeconfig
kubectl config set-context system:kube-scheduler \
--cluster=kubernetes \
--user=system:kube-scheduler \
--kubeconfig=kube-scheduler.kubeconfig
kubectl config use-context system:kube-scheduler --kubeconfig=kube-scheduler.kubeconfig
分发 kubeconfig 到所有 master 节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-scheduler.kubeconfig root@${node_ip}:/etc/kubernetes/
done
创建 kube-scheduler 配置文件
cd /opt/k8s/work
cat >kube-scheduler.yaml.template <<EOF
apiVersion: kubescheduler.config.k8s.io/v1alpha1
kind: KubeSchedulerConfiguration
bindTimeoutSeconds: 600
clientConnection:
burst: 200
kubeconfig: "/etc/kubernetes/kube-scheduler.kubeconfig"
qps: 100
enableContentionProfiling: false
enableProfiling: true
hardPodAffinitySymmetricWeight: 1
healthzBindAddress: 127.0.0.1:10251
leaderElection:
leaderElect: true
metricsBindAddress: ##NODE_IP##:10251
EOF
- –kubeconfig:指定 kubeconfig 文件路径,kube-scheduler 使用它连接和验证 kube-apiserver;
- –leader-elect=true:集群运行模式,启用选举功能;被选为 leader 的节点负责处理工作,其它节点为阻塞状态;
替换模板文件中的变量:
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for (( i=0; i < 3; i++ ))
do
sed -e "s/##NODE_NAME##/${NODE_NAMES[i]}/" -e "s/##NODE_IP##/${NODE_IPS[i]}/" kube-scheduler.yaml.template > kube-scheduler-${NODE_IPS[i]}.yaml
done
ls kube-scheduler*.yaml
分发 kube-scheduler 配置文件到所有 master 节点:
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-scheduler-${node_ip}.yaml root@${node_ip}:/etc/kubernetes/kube-scheduler.yaml
done
创建kube-scheduler启动文件
创建启动文件模板
cd /opt/k8s/work
cat > kube-scheduler.service.template <<EOF
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
[Service]
WorkingDirectory=${K8S_DIR}/kube-scheduler
ExecStart=/opt/k8s/bin/kube-scheduler \\
--config=/etc/kubernetes/kube-scheduler.yaml \\
--bind-address=##NODE_IP## \\
--secure-port=10259 \\
--port=0 \\
--tls-cert-file=/etc/kubernetes/cert/kube-scheduler.pem \\
--tls-private-key-file=/etc/kubernetes/cert/kube-scheduler-key.pem \\
--authentication-kubeconfig=/etc/kubernetes/kube-scheduler.kubeconfig \\
--client-ca-file=/etc/kubernetes/cert/ca.pem \\
--requestheader-allowed-names="" \\
--requestheader-client-ca-file=/etc/kubernetes/cert/ca.pem \\
--requestheader-extra-headers-prefix="X-Remote-Extra-" \\
--requestheader-group-headers=X-Remote-Group \\
--requestheader-username-headers=X-Remote-User \\
--authorization-kubeconfig=/etc/kubernetes/kube-scheduler.kubeconfig \\
--logtostderr=true \\
--v=2
Restart=always
RestartSec=5
StartLimitInterval=0
[Install]
WantedBy=multi-user.target
EOF
替换模板文件中的变量:
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for (( i=0; i < 3; i++ ))
do
sed -e "s/##NODE_NAME##/${NODE_NAMES[i]}/" -e "s/##NODE_IP##/${NODE_IPS[i]}/" kube-scheduler.service.template > kube-scheduler-${NODE_IPS[i]}.service
done
ls kube-scheduler*.service
分发启动文件至所有master节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-scheduler-${node_ip}.service root@${node_ip}:/etc/systemd/system/kube-scheduler.service
done
启动kube-scheduler
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p ${K8S_DIR}/kube-scheduler"
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable kube-scheduler && systemctl restart kube-scheduler"
done
检查服务运行状态
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "systemctl status kube-scheduler|grep Active"
done
查看输出的 metrics
注意:以下命令在 kube-scheduler 节点上执行。
- kube-scheduler 监听 10251 和 10259 端口:
- 10251:接收 http 请求,非安全端口,不需要认证授权;
- 10259:接收 https 请求,安全端口,需要认证授权;
- 两个接口都对外提供 /metrics 和 /healthz 的访问。
[root@node01 work]# curl -s http://10.0.20.11:10251/metrics|head
# HELP apiserver_audit_event_total Counter of audit events generated and sent to the audit backend.
# TYPE apiserver_audit_event_total counter
apiserver_audit_event_total 0
# HELP apiserver_audit_requests_rejected_total Counter of apiserver requests rejected due to an error in audit logging backend.
# TYPE apiserver_audit_requests_rejected_total counter
apiserver_audit_requests_rejected_total 0
# HELP apiserver_client_certificate_expiration_seconds Distribution of the remaining lifetime on the certificate used to authenticate a request.
# TYPE apiserver_client_certificate_expiration_seconds histogram
apiserver_client_certificate_expiration_seconds_bucket{le="0"} 0
apiserver_client_certificate_expiration_seconds_bucket{le="1800"} 0
查看当前leader
[root@node01 work]# kubectl get endpoints kube-scheduler --namespace=kube-system -o yaml
apiVersion: v1
kind: Endpoints
metadata:
annotations:
control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"node01.k8s.com_e83f3d5c-dcbe-48ad-aaa8-e1fcd2279573","leaseDurationSeconds":15,"acquireTime":"2019-12-05T08:41:51Z","renewTime":"2019-12-05T08:43:04Z","leaderTransitions":0}'
creationTimestamp: "2019-12-05T08:41:51Z"
name: kube-scheduler
namespace: kube-system
resourceVersion: "3144"
selfLink: /api/v1/namespaces/kube-system/endpoints/kube-scheduler
uid: 509afbcd-4369-4f44-a44a-e4d3fe84c31f
通过 apiserver 查看 schduler 状态
[root@node01 work]# kubectl get cs
NAME STATUS MESSAGE ERROR
scheduler Healthy ok
controller-manager Healthy ok
etcd-2 Healthy {"health":"true"}
etcd-1 Healthy {"health":"true"}
etcd-0 Healthy {"health":"true"}
这里看到 schduler 的状态已经是 ok
了,在 测试访问apiserver状态
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