可以使用高级调度分为：
- 节点选择器： nodeSelector、nodeName
- 节点亲和性调度： nodeAffinity
- Pod亲和性调度：PodAffinity
- Pod反亲和性调度：podAntiAffinity
nodeSelector, nodeName
cd; mkdir schedule; cd schedule/
vi pod-demo.yaml
# 内容为
apiVersion: v1
kind: Pod
metadata:
name: pod-demo
labels:
app: myapp
tier: frontend
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v1
nodeSelector:
disktype: harddisk
kubectl apply -f pod-demo.yaml
kubectl get pods
kubectl describe pod pod-demo
# 运行结果:
Warning FailedScheduling 2m3s (x25 over 3m15s) default-scheduler 0/3 nodes are available: 3 node(s) didn't match node selector.
# 打上标签
kubectl label node node2 disktype=harddisk
# 正常启动
kubectl get podsnodeAffinity
requiredDuringSchedulingIgnoredDuringExecution 硬亲和性 必须满足亲和性。
preferredDuringSchedulingIgnoredDuringExecution 软亲和性 能满足最好，不满足也没关系。
硬亲和性：
matchExpressions : 匹配表达式,这个标签可以指定一段，例如pod中定义的key为zone，operator为In(包含那些)，values为 foo和bar。就是在node节点中包含foo和bar的标签中调度
matchFields : 匹配字段 和上面的意思 不过他可以不定义标签值，可以定义
# 选择在 node 有 zone 标签值为 foo 或 bar 值的节点上运行 pod
vi pod-nodeaffinity-demo.yaml
# 内容为
apiVersion: v1
kind: Pod
metadata:
name: pod-node-affinity-demo
labels:
app: myapp
tier: frontend
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v1
affinity:
nodeAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
nodeSelectorTerms:
- matchExpressions:
- key: zone
operator: In
values:
- foo
- bar
kubectl apply -f pod-nodeaffinity-demo.yaml
kubectl describe pod pod-node-affinity-demo
# 运行结果:
Warning FailedScheduling 2s (x8 over 20s) default-scheduler 0/3 nodes are available: 3 node(s) didn't match node selector.
# 给其中一个node打上foo的标签
kubectl label node node1 zone=foo
# 正常启动
kubectl get pods软亲和性 :
cp pod-nodeaffinity-demo.yaml pod-nodeaffinity-demo-2.yaml
vi pod-nodeaffinity-demo-2.yaml
# 内容为
apiVersion: v1
kind: Pod
metadata:
name: pod-node-affinity-demo-2
labels:
app: myapp
tier: frontend
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v1
affinity:
nodeAffinity:
preferredDuringSchedulingIgnoredDuringExecution:
- preference:
matchExpressions:
- key: zone
operator: In
values:
- foo
- bar
weight: 60
kubectl apply -f pod-nodeaffinity-demo-2.yamlpodAffinity
Pod亲和性场景，我们的k8s集群的节点分布在不同的区域或者不同的机房，当服务A和服务B要求部署在同一个区域或者同一机房的时候，我们就需要亲和性调度了。
labelSelector : 选择跟那组Pod亲和
namespaces : 选择哪个命名空间
topologyKey : 指定节点上的哪个键
kubectl get pods
kubectl delete pod pod-node-affinity-demo pod-node-affinity-demo-2 pod-demo
cd ~/schedule/
vi pod-required-affinity-demo.yaml
# 内容为：
apiVersion: v1
kind: Pod
metadata:
name: pod-first
labels:
app: myapp
tier: frontend
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v1
---
apiVersion: v1
kind: Pod
metadata:
name: pod-second
labels:
app: db
tier: db
spec:
containers:
- name: busybox
image: busybox
imagePullPolicy: IfNotPresent
command: ["sh","-c","sleep 3600"]
affinity:
podAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- labelSelector:
matchExpressions:
- {key: app, operator: In, values: ["myapp"]}
topologyKey: kubernetes.io/hostname
kubectl apply -f pod-required-affinity-demo.yaml
kubectl get pods -o wide
# 运行结果，两个 pod 在同一 node 节点上
NAME READY STATUS RESTARTS AGE IP NODE
pod-first 1/1 Running 0 11s 10.244.1.6 node1
pod-second 1/1 Running 0 11s 10.244.1.5 node1podAntiAffinity
Pod反亲和性场景，当应用服务A和数据库服务B要求尽量不要在同一台节点上的时候。
kubectl delete -f pod-required-affinity-demo.yaml
cp pod-required-affinity-demo.yaml pod-required-anti-affinity-demo.yaml
vi pod-required-anti-affinity-demo.yaml
# 内容为
apiVersion: v1
kind: Pod
metadata:
name: pod-first
labels:
app: myapp
tier: frontend
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v1
---
apiVersion: v1
kind: Pod
metadata:
name: pod-second
labels:
app: backend
tier: db
spec:
containers:
- name: busybox
image: busybox:latest
imagePullPolicy: IfNotPresent
command: ["sh","-c","sleep 3600"]
affinity:
podAntiAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- labelSelector:
matchExpressions:
- {key: app, operator: In, values: ["myapp"]}
topologyKey: kubernetes.io/hostname
kubectl apply -f pod-required-anti-affinity-demo.yaml
kubectl get pods -o wide
# 运行结果，两个 pod 不在同一个 node
NAME READY STATUS RESTARTS AGE IP NODE
pod-first 1/1 Running 0 5s 10.244.2.4 node2
pod-second 1/1 Running 0 5s 10.244.1.7 node1
kubectl delete -f pod-required-anti-affinity-demo.yaml
# 如果硬反亲和性定义的标签两个节点都有，则第二个 Pod 没法进行调度，如下面的的 zone=foo
# 给两个 node 打上同一个标签 zone=foo
kubectl label nodes node2 zone=foo
kubectl label nodes node1 zone=foo
vi pod-required-anti-affinity-demo.yaml
# 内容为：
apiVersion: v1
kind: Pod
metadata:
name: pod-first
labels:
app: myapp
tier: frontend
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v1
---
apiVersion: v1
kind: Pod
metadata:
name: pod-second
labels:
app: backend
tier: db
spec:
containers:
- name: busybox
image: busybox:latest
imagePullPolicy: IfNotPresent
command: ["sh","-c","sleep 3600"]
affinity:
podAntiAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- labelSelector:
matchExpressions:
- {key: app, operator: In, values: ["myapp"]}
topologyKey: zone
kubectl apply -f pod-required-anti-affinity-demo.yaml
kubectl get pods -o wide
# 结果如下，pod-second 没法启动
NAME READY STATUS RESTARTS AGE IP NODE
pod-first 1/1 Running 0 12s 10.244.1.8 node1
pod-second 0/1 Pending 0 12s <none> <none>
kubectl delete -f pod-required-anti-affinity-demo.yaml污点容忍调度（Taint和Toleration）
taints and tolerations 允许将某个节点做标记，以使得所有的pod都不会被调度到该节点上。但是如果某个pod明确制定了 tolerates 则可以正常调度到被标记的节点上。
# 可以使用命令行为 Node 节点添加 Taints：
kubectl taint nodes node1 key=value:NoScheduleoperator可以定义为：
Equal：表示key是否等于value，默认
Exists：表示key是否存在，此时无需定义value
tain 的 effect 定义对 Pod 排斥效果:
NoSchedule：仅影响调度过程，对现存的Pod对象不产生影响；
NoExecute：既影响调度过程，也影响显著的Pod对象；不容忍的Pod对象将被驱逐
PreferNoSchedule: 表示尽量不调度
# 查看节点的 taint
kubectl describe node master
kubectl get pods -n kube-system
kubectl describe pods kube-apiserver-master -n kube-system
# 为 node1 打上污点
kubectl taint node node1 node-type=production:NoSchedule
vi deploy-demo.yaml
# 内容为：
apiVersion: apps/v1
kind: Deployment
metadata:
name: myapp-deploy
namespace: default
spec:
replicas: 2
selector:
matchLabels:
app: myapp
release: canary
template:
metadata:
labels:
app: myapp
release: canary
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v1
ports:
- name: http
containerPort: 80
kubectl apply -f deploy-demo.yaml
kubectl get pods -o wide
# 运行结果：
NAME READY STATUS RESTARTS AGE IP NODE
myapp-deploy-69b47bc96d-cwt79 1/1 Running 0 5s 10.244.2.6 node2
myapp-deploy-69b47bc96d-qqrwq 1/1 Running 0 5s 10.244.2.5 node2
# 为 node2 打上污点
kubectl taint node node2 node-type=dev:NoExecute
# NoExecute 将会驱逐没有容忍该污点的 pod，因两个node节点都有污点，pod没有定义容忍，导致没有节点可以启动pod
kubectl get pods -o wide
# 运行结果：
NAME READY STATUS RESTARTS AGE IP NODE
myapp-deploy-69b47bc96d-psl8f 0/1 Pending 0 14s <none> <none>
myapp-deploy-69b47bc96d-q296k 0/1 Pending 0 14s <none> <none>
# 定义Toleration(容忍)
vi deploy-demo.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: myapp-deploy
namespace: default
spec:
replicas: 2
selector:
matchLabels:
app: myapp
release: canary
template:
metadata:
labels:
app: myapp
release: canary
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v2
ports:
- name: http
containerPort: 80
tolerations:
- key: "node-type"
operator: "Equal"
value: "production"
effect: "NoSchedule"
kubectl apply -f deploy-demo.yaml
# pod 容忍 node1 的 tain ，可以在 node1 上运行
ubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE
myapp-deploy-65cc47f858-tmpnz 1/1 Running 0 10s 10.244.1.10 node1
myapp-deploy-65cc47f858-xnklh 1/1 Running 0 13s 10.244.1.9 node1
# 定义Toleration，是否存在 node-type 这个key 且 effect 值为 NoSchedule
vi deploy-demo.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: myapp-deploy
namespace: default
spec:
replicas: 2
selector:
matchLabels:
app: myapp
release: canary
template:
metadata:
labels:
app: myapp
release: canary
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v2
ports:
- name: http
containerPort: 80
tolerations:
- key: "node-type"
operator: "Exists"
value: ""
effect: "NoSchedule"
kubectl apply -f deploy-demo.yaml
kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE
myapp-deploy-559f559bcc-6jfqq 1/1 Running 0 10s 10.244.1.11 node1
myapp-deploy-559f559bcc-rlwp2 1/1 Running 0 9s 10.244.1.12 node1
##定义Toleration，是否存在 node-type 这个key 且 effect 值为空，则包含所有的值
vi deploy-demo.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: myapp-deploy
namespace: default
spec:
replicas: 2
selector:
matchLabels:
app: myapp
release: canary
template:
metadata:
labels:
app: myapp
release: canary
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v2
ports:
- name: http
containerPort: 80
tolerations:
- key: "node-type"
operator: "Exists"
value: ""
effect: ""
kubectl apply -f deploy-demo.yaml
# 两个 pod 均衡调度到两个节点
kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE
myapp-deploy-5d9c6985f5-hn4k2 1/1 Running 0 2m 10.244.1.13 node1
myapp-deploy-5d9c6985f5-lkf9q 1/1 Running 0 2m 10.244.2.7 node2
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