本文主要介绍kubernetes调度框架中的NodeName和NodeSelector。

1、spec.nodeName用于强制约束将Pod调度到指定的Node节点上，这里说是“调度”，但其实指定了nodeName的Pod会直接跳过Scheduler的调度逻辑，直接写入PodList列表，该匹配规则是强制匹配。

如下例：

apiVersion: v1

kind: ReplicationController

metadata:

name: nginx

labels:

name: nginx

spec:

replicas: 1

selector:

name: nginx

template:

metadata:

labels:

name: nginx

spec:

nodeName: master-168-32

containers:

– name: nginx

image: nginx-ip:0.4

ports:

– containerPort: 80

volumeMounts:

– name: httpd-storage

mountPath: /usr/share/nginx/html

volumes:

– name: httpd-storage

nfs:

server: 10.168.170.218

path: "/data/web"

2、spec.nodeSelector是通过kubernetes的label-selector机制进行节点选择，由scheduler调度策略MatchNodeSelector进行label匹配，调度pod到目标节点，该匹配规则是强制约束。启用节点选择器的步骤为：

[root@master-168-32]# kubectl label nodes node-168-169 china.com/server=high

node "node-168-169" labeled

[root@master-168-32]# kubectl get nodes node-168-169 –show-labels

NAME           STATUS    ROLES     AGE       VERSION   LABELS

node-168-169   Ready         57d       v1.9.0    beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,xxxxxx.com/server=high,kubernetes.io/hostname=node-168-169

如下例:

apiVersion: v1

kind: ReplicationController

metadata:

name: nginxnode

labels:

name: nginxnode

spec:

replicas: 1

selector:

name: nginxnode

template:

metadata:

labels:

name: nginxnode

spec:

nodeSelector:

china.com/server: high

containers:

– name: nginxnode

image: reg.xxxxxx.com/library/nginx-ip:0.4

ports:

– containerPort: 80

volumeMounts:

– name: httpd-storage

mountPath: /usr/share/nginx/html

volumes:

– name: httpd-storage

nfs:

server: 10.168.170.218

path: "/data/web"