NetworkPolicy
36. Egress
36.1 NetworkPolicy
- 概述
#flannel不支持这个策略 基于NetworkPolicy在三层(网络层)或四层(传输层)控制拒绝或允许请求流量。 1.允许或拒绝特定的pod请求目的namespace中的目的pod的所有或指定端口 2.允许或拒绝特定的namespace请求目的namespace中的所有或特定的pod所有或指定端口 3.允许或拒绝特定的源IP范围或IP地址请求目的pod的所有或特定端口
36.2 实现跨namespace通信及访问限制
1.kubernetes 1.24.x,calico网络组件,2个node节点或以上。
2.两个namespace,linux和python,分别代表不同项目的Pod。
3.每个namespace运行多个pod,且pod可以运行在不同的node主机。
4.测试环境为每个namespace分别运行一个nginx和一个tomcat pod,用于测试不同主机的Pod运行在同一个ns的场景、以及跨ns的访问通信及访问限制。
- 创建namespae
kubectl create namespace linux kubectl create namespace python kubectl label namespaces linux nsname=linux kubectl label namespaces python nsname=python
- 在两个namespace中分别创建YAML
linux ns部署nginx和tomcat,并让Nginx可以将来自于/app的请求转发至当前namespace的tomcat pod
python ns部署Nginx和tomcat,并让Nginx可以将来自于/app的请求转发至当前namespace的tomcat pod
#linux root@k8s-master1:~/NetWorkPolicy-case/linux-ns1# cat nginx.yaml kind: Deployment #apiVersion: extensions/v1beta1 apiVersion: apps/v1 metadata: labels: app: linux-nginx-deployment-label name: linux-nginx-deployment namespace: linux spec: replicas: 1 selector: matchLabels: app: linux-nginx-selector template: metadata: labels: app: linux-nginx-selector spec: containers: - name: linux-nginx-container image: nginx:1.20.2-alpine #command: ["/apps/tomcat/bin/run_tomcat.sh"] #imagePullPolicy: IfNotPresent imagePullPolicy: Always ports: - containerPort: 80 protocol: TCP name: http - containerPort: 443 protocol: TCP name: https env: - name: "password" value: "123456" - name: "age" value: "18" # resources: # limits: # cpu: 2 # memory: 2Gi # requests: # cpu: 500m # memory: 1Gi --- kind: Service apiVersion: v1 metadata: labels: app: linux-nginx-service-label name: linux-nginx-service namespace: linux spec: type: NodePort ports: - name: http port: 80 protocol: TCP targetPort: 80 nodePort: 30008 - name: https port: 443 protocol: TCP targetPort: 443 nodePort: 30446 selector: app: linux-nginx-selector root@k8s-master1:~/NetWorkPolicy-case/linux-ns1# cat tomcat.yaml kind: Deployment #apiVersion: extensions/v1beta1 apiVersion: apps/v1 metadata: labels: app: linux-tomcat-app1-deployment-label name: linux-tomcat-app1-deployment namespace: linux spec: replicas: 1 selector: matchLabels: app: linux-tomcat-app1-selector template: metadata: labels: app: linux-tomcat-app1-selector spec: containers: - name: linux-tomcat-app1-container image: tomcat:7.0.109-jdk8-openjdk #command: ["/apps/tomcat/bin/run_tomcat.sh"] #imagePullPolicy: IfNotPresent imagePullPolicy: Always ports: - containerPort: 8080 protocol: TCP name: http env: - name: "password" value: "123456" - name: "age" value: "18" # resources: # limits: # cpu: 2 # memory: 2Gi # requests: # cpu: 500m # memory: 1Gi --- kind: Service apiVersion: v1 metadata: labels: app: linux-tomcat-app1-service-label name: linux-tomcat-app1-service namespace: linux spec: type: NodePort ports: - name: http port: 80 protocol: TCP targetPort: 8080 nodePort: 30006 selector: app: linux-tomcat-app1-selector #python root@k8s-master1:~/NetWorkPolicy-case/python-ns2# cat nginx.yaml kind: Deployment #apiVersion: extensions/v1beta1 apiVersion: apps/v1 metadata: labels: app: python-nginx-deployment-label name: python-nginx-deployment namespace: python spec: replicas: 1 selector: matchLabels: app: python-nginx-selector template: metadata: labels: app: python-nginx-selector project: python spec: containers: - name: python-nginx-container image: nginx:1.20.2-alpine #command: ["/apps/tomcat/bin/run_tomcat.sh"] #imagePullPolicy: IfNotPresent imagePullPolicy: Always ports: - containerPort: 80 protocol: TCP name: http - containerPort: 443 protocol: TCP name: https env: - name: "password" value: "123456" - name: "age" value: "18" # resources: # limits: # cpu: 2 # memory: 2Gi # requests: # cpu: 500m # memory: 1Gi --- kind: Service apiVersion: v1 metadata: labels: app: python-nginx-service-label name: python-nginx-service namespace: python spec: type: NodePort ports: - name: http port: 80 protocol: TCP targetPort: 80 nodePort: 30016 - name: https port: 443 protocol: TCP targetPort: 443 nodePort: 30456 selector: app: python-nginx-selector project: python #一个或多个selector,至少能匹配目标pod的一个标签 root@k8s-master1:~/NetWorkPolicy-case/python-ns2# cat tomcat.yaml kind: Deployment #apiVersion: extensions/v1beta1 apiVersion: apps/v1 metadata: labels: app: python-tomcat-app1-deployment-label name: python-tomcat-app1-deployment namespace: python spec: replicas: 1 selector: matchLabels: app: python-tomcat-app1-selector template: metadata: labels: app: python-tomcat-app1-selector spec: # nodeName: 172.31.7.113 containers: - name: python-tomcat-app1-container image: tomcat:7.0.109-jdk8-openjdk #command: ["/apps/tomcat/bin/run_tomcat.sh"] #imagePullPolicy: IfNotPresent imagePullPolicy: Always ports: - containerPort: 8080 protocol: TCP name: http env: - name: "password" value: "123456" - name: "age" value: "18" # resources: # limits: # cpu: 2 # memory: 2Gi # requests: # cpu: 500m # memory: 1Gi --- kind: Service apiVersion: v1 metadata: labels: app: python-tomcat-app1-service-label name: python-tomcat-app1-service namespace: python spec: type: NodePort ports: - name: http port: 80 protocol: TCP targetPort: 8080 nodePort: 30015 selector: app: python-tomcat-app1-selector
- 对Nginx都创建首页
#思考 运行在Linux ns的Nginx能否将请求转发至运行在Python ns的tomcat? 答案默认是可以的 kubectl exec -it -n python python-tomcat-app1-deployment-7bf9bb6989-7szqk bash cd webapps mkdir app echo 'app demo python' >app/index.jsp #测试访问 root@k8s-master1:~# curl http://10.0.0.102:30015/app/index.jsp app demo python
36.3 测试网络限制
- podSelector
#先在default名称空间下访问查看是否可以通信 是可以的 root@k8s-master1:~# kubectl exec -it net-test bash [root@net-test /]# curl 10.200.224.5:8080/app/index.jsp app demo python #ingress #vim case1-ingress-podSelector.yaml apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: tomcat-access--networkpolicy namespace: python spec: policyTypes: - Ingress podSelector: matchLabels: app: python-tomcat-app1-selector #对匹配到的目的Pod应用以下规则 ingress: #入栈规则,如果指定目标端口就是匹配全部端口和协议,协议TCP, UDP, or SCTP - from: - podSelector: matchLabels: #app: python-nginx-selector #如果存在多个matchLabel条件,如果存在多个matchLabel条件,是and的关系,即要同时满足条件A、条件B、条件X project: "python" #只有带这个标签的pod才可以访问,没有允许的访问就是拒绝 root@k8s-master1:~/NetWorkPolicy-case/python-ns2# kubectl get networkpolicies.networking.k8s.io -n python NAME POD-SELECTOR AGE tomcat-access--networkpolicy app=python-tomcat-app1-selector 13s #加上这个策略之后default就不能访问了因为他没有这个标签
- 结果
1.不允许从其它namespace访问目标pod,即默认禁止了跨ns访问目标pod
2.
3.不允许从宿主机访问目标pod
4.该策略只允许同namespce含有特定标签的源pod访问目标pod,比如tomcat只允许了有特定标签的源pod Nginx访问
5.该策略不影响其它namespace的pod内部之间的相互访问,即Linux的pod与linux的pod访问正常
6.该策略不影响各namespace的pod与飞明确禁止的pod之间的访问,即Linux的pod访问Python的其它pod也正常
- podSelector + 端口限制
以pod为限制单位,只允许同namespace含有特定标签的源pod访问目标pod的所有端口
root@k8s-master1:~/NetWorkPolicy-case/python-ns2# cat case2-ingress-podSelector-ns-SinglePort.yaml apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: tomcat-access--networkpolicy namespace: python spec: policyTypes: - Ingress podSelector: matchLabels: app: python-tomcat-app1-selector ingress: - from: - podSelector: matchLabels: #app: python-nginx-selector #指定访问源的匹配条件,如果存在多个matchLabel条件,是and的关系,即要同时满足条件A、条件B、条件X project: "python" ports: #入栈规则,如果指定目标端口就是匹配全部端口和协议,协议TCP, UDP, or SCTP - protocol: TCP port: 8080 #允许通过TCP协议访问目标pod的8080端口,但是其它没有允许的端口将全部禁止访问 #port: 80
- podSelector + matchLabels: {} 匹配python名称空间下所有pod
允许同namespace的所有pod访问当前namespace的目标pod多个指定端口或所有端口
root@k8s-master1:~/NetWorkPolicy-case/python-ns2# cat case3-ingress-podSelector-ns-MultiPort.yaml apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: tomcat-access-networkpolicy namespace: python spec: policyTypes: - Ingress podSelector: #目标pod matchLabels: app: python-tomcat-app1-selector ingress: - from: - podSelector: #匹配源pod,matchLabels: {}为不限制源pod即允许所有pod,写法等同于resources(不加就是不限制) matchLabels: {} #不加ports就是所有端口都可以访问 ports: #入栈规则,如果指定目标端口就是匹配全部端口和协议,协议TCP, UDP, or SCTP - protocol: TCP port: 8080 #允许通过TCP协议访问目标pod的8080端口,但是其它没有允许的端口将全部禁止访问 #port: 80 - protocol: TCP port: 3306 - protocol: TCP port: 6379
- podSelector + ipBlock 白名单
1.只要在白名单范围内没有被except指定禁止的源 pod IP都允许访问
2.在只设置了ipBlock匹配的前提下,其它namespace中没有在except范围的pod也可以访问目标pod,及 linux ns中的pod只要不在except地址范围内,也可以访问Python ns中的pod了
root@k8s-master1:~/NetWorkPolicy-case/python-ns2# cat case5-ingress-ipBlock.yaml.bak apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: tomcat-access--networkpolicy namespace: python spec: policyTypes: - Ingress podSelector: #目标pod matchLabels: app: python-tomcat-app1-selector ingress: - from: # - podSelector: #匹配源pod,matchLabels: {}为不限制源pod即允许所有pod,写法等同于resources(不加就是不限制) # matchLabels: {} - ipBlock: #这个cidr就是你初始化时候设置的地址段 cidr: 10.200.0.0/16 #白名单,允许访问的地址范围,没有允许的将禁止访问目标pod except: - 10.200.219.0/24 #在以上范围内禁止访问的源IP地址 - 10.200.229.0/24 #在以上范围内禁止访问的源IP地址 - 10.200.207.31/32 #在以上范围内禁止访问的源IP地址 ports: #入栈规则,如果指定目标端口就是匹配全部端口和协议,协议TCP, UDP, or SCTP - protocol: TCP port: 8080 #允许通过TCP协议访问目标pod的8080端口,但是其它没有允许的端口将全部禁止访问 #port: 80 - protocol: TCP port: 3306 - protocol: TCP port: 6379
- podSelector + namespaceSelector
1.被明确允许的namespace中的pod可以访问目标pod
2.没有明确声明允许的namespace将禁止访问
3.没有明确声明允许的话,即使同一个namespace也禁止访问
4.比如只允许了linux和python两个namespace,那么default中的pod将无法访问
root@k8s-master1:~/NetWorkPolicy-case/python-ns2# cat case6-ingress-namespaceSelector.yaml apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: tomcat-access--networkpolicy namespace: python spec: policyTypes: - Ingress podSelector: #目标pod matchLabels: {} #允许访问python namespace 中的所有pod # app: python-tomcat-app1-selector #可以只允许访问python namespace中指定的pod ingress: - from: # - podSelector: #匹配源pod,matchLabels: {}为不限制源pod即允许所有pod,写法等同于resources(不加就是不限制) # matchLabels: {} # - ipBlock: # cidr: 10.200.0.0/16 #指定禁止访问的源网段 # except: # - 10.200.218.0/24 #在以上范围内禁止访问的源IP地址 - namespaceSelector: # matchLabels: {} #允许所有namespace访问python namespace指定的目标端口或指定的pod加指定端口 matchLabels: nsname: linux #只允许指定的namespace访问 - namespaceSelector: matchLabels: nsname: python #只允许指定的namespace访问 ports: #入栈规则,如果指定目标端口就是匹配全部端口和协议,协议TCP, UDP, or SCTP - protocol: TCP port: 8080 #允许通过TCP协议访问目标pod的8080端口,但是其它没有允许的端口将全部禁止访问 #port: 80 - protocol: TCP port: 3306 - protocol: TCP port: 6379
- podSelector + egress pod出口方向的IP及目的端口限制-只允许访问指定的目的地址范围及端口
限制指定的pod可以访问指定的IP
1.基于Egress白名单,定义ns中匹配成功的pod可以访问ipBlock指定的地址和ports指定的端口
2.匹配成功的pod访问未明确定义在Egress的白名单的其它IP的请求,将拒绝
3.没有匹配成功的源pod,主动发起的出口访问请求不受影响
root@k8s-master1:~/NetWorkPolicy-case/python-ns2# cat case7-Egress-ipBlock.yaml apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: egress-access-networkpolicy namespace: python spec: policyTypes: - Egress podSelector: #目标pod选择器 matchLabels: #基于label匹配目标pod app: python-tomcat-app1-selector #匹配python namespace中app的值为python-tomcat-app1-selector的pod,然后基于egress中的指定网络策略进行出口方向的网络限制 egress: - to: - ipBlock: cidr: 10.200.0.0/16 #允许匹配到的pod出口访问的目的CIDR地址范围 - ipBlock: cidr: 172.31.7.106/32 #允许匹配到的pod出口访问的目的主机 - ipBlock: cidr: 0.0.0.0/0 #允许匹配到的pod出口访问的目的主机 ports: - protocol: TCP port: 80 #允许匹配到的pod访问目的端口为80的访问 - protocol: TCP port: 53 #允许匹配到的pod访问目的端口为53 即DNS的解析 - protocol: UDP port: 53 #允许匹配到的pod访问目的端口为53 即DNS的解析
- Pod出口方向目的Pod限制-只允许访问指定的Pod及端口
1.匹配成功的源pod只能访问指定的目的pod的指定端口
2.其它没有允许的出口请求将禁止访问
root@k8s-master1:~/NetWorkPolicy-case/python-ns2# cat case8-Egress-PodSelector.yaml apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: egress-access-networkpolicy namespace: python spec: policyTypes: - Egress podSelector: #目标pod选择器 matchLabels: #基于label匹配目标pod app: python-nginx-selector #匹配python namespace中app的值为python-tomcat-app1-selector的pod,然后基于egress中的指定网络策略进行出口方向的网络限制 egress: - to: # - ipBlock: # cidr: 10.200.0.0/16 #允许访问的目的CIDR地址范围 # - ipBlock: # cidr: 172.31.7.106/32 #允许访问的目的主机地址 # - ipBlock: # cidr: 10.200.218.4/32 #白名单,允许访问的目的主机地址 - podSelector: #匹配pod,matchLabels: {}为不限制源pod即允许所有pod,写法等同于resources(不加就是不限制) matchLabels: app: python-tomcat-app1-selector ports: - protocol: TCP port: 8080 #允许80端口的访问 - protocol: TCP port: 53 #允许DNS的解析 - protocol: UDP port: 53
- Pod出口方向目的IP及目的端口限制-只允许访问指定的目的地址范围及端口
限制匹配成功的pod没有访问指定的namespace
1.匹配成功的源pod可以访问指定的目标namespace
2.不能访问除指定的namespace以外的其它namespace及外网
3.比如允许指定的源pod访问linux和python ns中的8080、3306、6379等端口,但是其它ns无法访问
root@k8s-master1:~/NetWorkPolicy-case/python-ns2# cat case9-Egress-namespaceSelector.yaml apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: egress-access-networkpolicy namespace: python spec: policyTypes: - Egress podSelector: #目标pod选择器 matchLabels: #基于label匹配目标pod app: python-nginx-selector #匹配python namespace中app的值为python-tomcat-app1-selector的pod,然后基于egress中的指定网络策略进行出口方向的网络限制 egress: - to: # - ipBlock: # cidr: 10.200.0.0/16 #允许访问的目的CIDR地址范围 # - ipBlock: # cidr: 172.31.7.106/32 #允许访问的目的主机地址 # - ipBlock: # cidr: 10.200.218.4/32 #允许访问的目的主机地址 # - podSelector: #匹配pod,matchLabels: {}为不限制源pod即允许所有pod,写法等同于resources(不加就是不限制) # matchLabels: # app: python-tomcat-app1-selector - namespaceSelector: matchLabels: nsname: python #指定允许访问的目的namespace - namespaceSelector: matchLabels: nsname: linux #指定允许访问的目的namespace ports: - protocol: TCP port: 8080 #允许80端口的访问 - protocol: TCP port: 53 #允许DNS的解析 - protocol: UDP port: 53