Chapter 4. Network policies 4.1. About network policies Learn how network policies work for MicroShift to restrict or allow network traffic to pods in your cluster. 4.1.1. How network policy works in MicroShift In a cluster using the default OVN-Kubernetes Container Network Interface (CNI) plugin for MicroShift, network isolation is controlled by both firewalld, which is configured on the host, and by NetworkPolicy objects created within MicroShift. Simultaneous use of firewalld and NetworkPolicy is supported. Network policies work only within boundaries of OVN-Kubernetes-controlled traffic, so they can apply to every situation except for hostPort/hostNetwork enabled pods. Firewalld settings also do not apply to hostPort/hostNetwork enabled pods. Note Firewalld rules run before any NetworkPolicy is enforced. Warning Network policy does not apply to the host network namespace. Pods with host networking enabled are unaffected by network policy rules. However, pods connecting to the host-networked pods might be affected by the network policy rules. Network policies cannot block traffic from localhost. By default, all pods in a MicroShift node are accessible from other pods and network endpoints. To isolate one or more pods in a cluster, you can create NetworkPolicy objects to indicate allowed incoming connections. You can create and delete NetworkPolicy objects. If a pod is matched by selectors in one or more NetworkPolicy objects, then the pod accepts only connections that are allowed by at least one of those NetworkPolicy objects. A pod that is not selected by any NetworkPolicy objects is fully accessible. A network policy applies to only the TCP, UDP, ICMP, and SCTP protocols. Other protocols are not affected. The following example NetworkPolicy objects demonstrate supporting different scenarios: Deny all traffic: To make a project deny by default, add a NetworkPolicy object that matches all pods but accepts no traffic: kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: deny-by-default spec: podSelector: {} ingress: [] Allow connections from the default router, which is the ingress in MicroShift: To allow connections from the MicroShift default router, add the following NetworkPolicy object: apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: allow-from-openshift-ingress spec: ingress: - from: - namespaceSelector: matchLabels: ingresscontroller.operator.openshift.io/deployment-ingresscontroller: default podSelector: {} policyTypes: - Ingress Only accept connections from pods within the same namespace: To make pods accept connections from other pods in the same namespace, but reject all other connections from pods in other namespaces, add the following NetworkPolicy object: kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: allow-same-namespace spec: podSelector: {} ingress: - from: - podSelector: {} Only allow HTTP and HTTPS traffic based on pod labels: To enable only HTTP and HTTPS access to the pods with a specific label ( role=frontend in following example), add a NetworkPolicy object similar to the following: kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: allow-http-and-https spec: podSelector: matchLabels: role: frontend ingress: - ports: - protocol: TCP port: 80 - protocol: TCP port: 443 Accept connections by using both namespace and pod selectors: To match network traffic by combining namespace and pod selectors, you can use a NetworkPolicy object similar to the following: kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: allow-pod-and-namespace-both spec: podSelector: matchLabels: name: test-pods ingress: - from: - namespaceSelector: matchLabels: project: project_name podSelector: matchLabels: name: test-pods NetworkPolicy objects are additive, which means you can combine multiple NetworkPolicy objects together to satisfy complex network requirements. For example, for the NetworkPolicy objects defined in examples, you can define both allow-same-namespace and allow-http-and-https policies. That configuration allows the pods with the label role=frontend to accept any connection allowed by each policy. That is, connections on any port from pods in the same namespace, and connections on ports 80 and 443 from pods in any namespace. 4.1.2. Optimizations for network policy with OVN-Kubernetes network plugin When designing your network policy, refer to the following guidelines: For network policies with the same spec.podSelector spec, it is more efficient to use one network policy with multiple ingress or egress rules, than multiple network policies with subsets of ingress or egress rules. Every ingress or egress rule based on the podSelector or namespaceSelector spec generates the number of OVS flows proportional to number of pods selected by network policy + number of pods selected by ingress or egress rule . Therefore, it is preferable to use the podSelector or namespaceSelector spec that can select as many pods as you need in one rule, instead of creating individual rules for every pod. For example, the following policy contains two rules: apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: test-network-policy spec: podSelector: {} ingress: - from: - podSelector: matchLabels: role: frontend - from: - podSelector: matchLabels: role: backend The following policy expresses those same two rules as one: apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: test-network-policy spec: podSelector: {} ingress: - from: - podSelector: matchExpressions: - {key: role, operator: In, values: [frontend, backend]} The same guideline applies to the spec.podSelector spec. If you have the same ingress or egress rules for different network policies, it might be more efficient to create one network policy with a common spec.podSelector spec. For example, the following two policies have different rules: apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: policy1 spec: podSelector: matchLabels: role: db ingress: - from: - podSelector: matchLabels: role: frontend --- apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: policy2 spec: podSelector: matchLabels: role: client ingress: - from: - podSelector: matchLabels: role: frontend The following network policy expresses those same two rules as one: apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: policy3 spec: podSelector: matchExpressions: - {key: role, operator: In, values: [db, client]} ingress: - from: - podSelector: matchLabels: role: frontend You can apply this optimization when only multiple selectors are expressed as one. In cases where selectors are based on different labels, it may not be possible to apply this optimization. In those cases, consider applying some new labels for network policy optimization specifically. 4.2. Creating network policies You can create a network policy for a namespace. 4.2.1. Example NetworkPolicy object The following annotates an example NetworkPolicy object: kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: allow-27107 1 spec: podSelector: 2 matchLabels: app: mongodb ingress: - from: - podSelector: 3 matchLabels: app: app ports: 4 - protocol: TCP port: 27017 1 The name of the NetworkPolicy object. 2 A selector that describes the pods to which the policy applies. 3 A selector that matches the pods from which the policy object allows ingress traffic. The selector matches pods in the same namespace as the NetworkPolicy. 4 A list of one or more destination ports on which to accept traffic. 4.2.2. Creating a network policy using the CLI To define granular rules describing ingress or egress network traffic allowed for namespaces in your cluster, you can create a network policy. Prerequisites You installed the OpenShift CLI ( oc ). You are working in the namespace that the network policy applies to. Procedure Create a policy rule: Create a <policy_name>.yaml file: USD touch <policy_name>.yaml where: <policy_name> Specifies the network policy file name. Define a network policy in the file that you just created, such as in the following examples: Deny ingress from all pods in all namespaces This is a fundamental policy, blocking all cross-pod networking other than cross-pod traffic allowed by the configuration of other Network Policies. kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: deny-by-default spec: podSelector: {} policyTypes: - Ingress ingress: [] Allow ingress from all pods in the same namespace kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: allow-same-namespace spec: podSelector: ingress: - from: - podSelector: {} Allow ingress traffic to one pod from a particular namespace This policy allows traffic to pods labelled pod-a from pods running in namespace-y . kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: allow-traffic-pod spec: podSelector: matchLabels: pod: pod-a policyTypes: - Ingress ingress: - from: - namespaceSelector: matchLabels: kubernetes.io/metadata.name: namespace-y To create the network policy object, enter the following command: USD oc apply -f <policy_name>.yaml -n <namespace> where: <policy_name> Specifies the network policy file name. <namespace> Optional: Specifies the namespace if the object is defined in a different namespace than the current namespace. Example output networkpolicy.networking.k8s.io/deny-by-default created 4.2.3. Creating a default deny all network policy This is a fundamental policy, blocking all cross-pod networking other than network traffic allowed by the configuration of other deployed network policies. This procedure enforces a default deny-by-default policy. Prerequisites You installed the OpenShift CLI ( oc ). You are working in the namespace that the network policy applies to. Procedure Create the following YAML that defines a deny-by-default policy to deny ingress from all pods in all namespaces. Save the YAML in the deny-by-default.yaml file: kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: deny-by-default namespace: default 1 spec: podSelector: {} 2 ingress: [] 3 1 namespace: default deploys this policy to the default namespace. 2 podSelector: is empty, this means it matches all the pods. Therefore, the policy applies to all pods in the default namespace. 3 There are no ingress rules specified. This causes incoming traffic to be dropped to all pods. Apply the policy by entering the following command: USD oc apply -f deny-by-default.yaml Example output networkpolicy.networking.k8s.io/deny-by-default created 4.2.4. Creating a network policy to allow traffic from external clients With the deny-by-default policy in place you can proceed to configure a policy that allows traffic from external clients to a pod with the label app=web . Note Firewalld rules run before any NetworkPolicy is enforced. Follow this procedure to configure a policy that allows external service from the public Internet directly or by using a Load Balancer to access the pod. Traffic is only allowed to a pod with the label app=web . Prerequisites You installed the OpenShift CLI ( oc ). You are working in the namespace that the network policy applies to. Procedure Create a policy that allows traffic from the public Internet directly or by using a load balancer to access the pod. Save the YAML in the web-allow-external.yaml file: kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: web-allow-external namespace: default spec: policyTypes: - Ingress podSelector: matchLabels: app: web ingress: - {} Apply the policy by entering the following command: USD oc apply -f web-allow-external.yaml Example output networkpolicy.networking.k8s.io/web-allow-external created 4.2.5. Creating a network policy allowing traffic to an application from all namespaces Follow this procedure to configure a policy that allows traffic from all pods in all namespaces to a particular application. Prerequisites You installed the OpenShift CLI ( oc ). You are working in the namespace that the network policy applies to. Procedure Create a policy that allows traffic from all pods in all namespaces to a particular application. Save the YAML in the web-allow-all-namespaces.yaml file: kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: web-allow-all-namespaces namespace: default spec: podSelector: matchLabels: app: web 1 policyTypes: - Ingress ingress: - from: - namespaceSelector: {} 2 1 Applies the policy only to app:web pods in default namespace. 2 Selects all pods in all namespaces. Note By default, if you omit specifying a namespaceSelector it does not select any namespaces, which means the policy allows traffic only from the namespace the network policy is deployed to. Apply the policy by entering the following command: USD oc apply -f web-allow-all-namespaces.yaml Example output networkpolicy.networking.k8s.io/web-allow-all-namespaces created Verification Start a web service in the default namespace by entering the following command: USD oc run web --namespace=default --image=nginx --labels="app=web" --expose --port=80 Run the following command to deploy an alpine image in the secondary namespace and to start a shell: USD oc run test-USDRANDOM --namespace=secondary --rm -i -t --image=alpine -- sh Run the following command in the shell and observe that the request is allowed: # wget -qO- --timeout=2 http://web.default Expected output <!DOCTYPE html> <html> <head> <title>Welcome to nginx!</title> <style> html { color-scheme: light dark; } body { width: 35em; margin: 0 auto; font-family: Tahoma, Verdana, Arial, sans-serif; } </style> </head> <body> <h1>Welcome to nginx!</h1> <p>If you see this page, the nginx web server is successfully installed and working. Further configuration is required.</p> <p>For online documentation and support please refer to <a href="http://nginx.org/">nginx.org</a>.<br/> Commercial support is available at <a href="http://nginx.com/">nginx.com</a>.</p> <p><em>Thank you for using nginx.</em></p> </body> </html> 4.2.6. Creating a network policy allowing traffic to an application from a namespace Follow this procedure to configure a policy that allows traffic to a pod with the label app=web from a particular namespace. You might want to do this to: Restrict traffic to a production database only to namespaces where production workloads are deployed. Enable monitoring tools deployed to a particular namespace to scrape metrics from the current namespace. Prerequisites You installed the OpenShift CLI ( oc ). You are working in the namespace that the network policy applies to. Procedure Create a policy that allows traffic from all pods in a particular namespaces with a label purpose=production . Save the YAML in the web-allow-prod.yaml file: kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: web-allow-prod namespace: default spec: podSelector: matchLabels: app: web 1 policyTypes: - Ingress ingress: - from: - namespaceSelector: matchLabels: purpose: production 2 1 Applies the policy only to app:web pods in the default namespace. 2 Restricts traffic to only pods in namespaces that have the label purpose=production . Apply the policy by entering the following command: USD oc apply -f web-allow-prod.yaml Example output networkpolicy.networking.k8s.io/web-allow-prod created Verification Start a web service in the default namespace by entering the following command: USD oc run web --namespace=default --image=nginx --labels="app=web" --expose --port=80 Run the following command to create the prod namespace: USD oc create namespace prod Run the following command to label the prod namespace: USD oc label namespace/prod purpose=production Run the following command to create the dev namespace: USD oc create namespace dev Run the following command to label the dev namespace: USD oc label namespace/dev purpose=testing Run the following command to deploy an alpine image in the dev namespace and to start a shell: USD oc run test-USDRANDOM --namespace=dev --rm -i -t --image=alpine -- sh Run the following command in the shell and observe that the request is blocked: # wget -qO- --timeout=2 http://web.default Expected output wget: download timed out Run the following command to deploy an alpine image in the prod namespace and start a shell: USD oc run test-USDRANDOM --namespace=prod --rm -i -t --image=alpine -- sh Run the following command in the shell and observe that the request is allowed: # wget -qO- --timeout=2 http://web.default Expected output <!DOCTYPE html> <html> <head> <title>Welcome to nginx!</title> <style> html { color-scheme: light dark; } body { width: 35em; margin: 0 auto; font-family: Tahoma, Verdana, Arial, sans-serif; } </style> </head> <body> <h1>Welcome to nginx!</h1> <p>If you see this page, the nginx web server is successfully installed and working. Further configuration is required.</p> <p>For online documentation and support please refer to <a href="http://nginx.org/">nginx.org</a>.<br/> Commercial support is available at <a href="http://nginx.com/">nginx.com</a>.</p> <p><em>Thank you for using nginx.</em></p> </body> </html> 4.3. Editing a network policy You can edit an existing network policy for a namespace. Typical edits might include changes to the pods to which the policy applies, allowed ingress traffic, and the destination ports on which to accept traffic. The apiVersion , kind , and name fields must not be changed when editing NetworkPolicy objects, as these define the resource itself. 4.3.1. Editing a network policy You can edit a network policy in a namespace. Prerequisites You installed the OpenShift CLI ( oc ). You are working in the namespace where the network policy exists. Procedure Optional: To list the network policy objects in a namespace, enter the following command: USD oc get networkpolicy where: <namespace> Optional: Specifies the namespace if the object is defined in a different namespace than the current namespace. Edit the network policy object. If you saved the network policy definition in a file, edit the file and make any necessary changes, and then enter the following command. USD oc apply -n <namespace> -f <policy_file>.yaml where: <namespace> Optional: Specifies the namespace if the object is defined in a different namespace than the current namespace. <policy_file> Specifies the name of the file containing the network policy. If you need to update the network policy object directly, enter the following command: USD oc edit networkpolicy <policy_name> -n <namespace> where: <policy_name> Specifies the name of the network policy. <namespace> Optional: Specifies the namespace if the object is defined in a different namespace than the current namespace. Confirm that the network policy object is updated. USD oc describe networkpolicy <policy_name> -n <namespace> where: <policy_name> Specifies the name of the network policy. <namespace> Optional: Specifies the namespace if the object is defined in a different namespace than the current namespace. 4.3.2. Example NetworkPolicy object The following annotates an example NetworkPolicy object: kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: allow-27107 1 spec: podSelector: 2 matchLabels: app: mongodb ingress: - from: - podSelector: 3 matchLabels: app: app ports: 4 - protocol: TCP port: 27017 1 The name of the NetworkPolicy object. 2 A selector that describes the pods to which the policy applies. 3 A selector that matches the pods from which the policy object allows ingress traffic. The selector matches pods in the same namespace as the NetworkPolicy. 4 A list of one or more destination ports on which to accept traffic. 4.4. Deleting a network policy You can delete a network policy from a namespace. 4.4.1. Deleting a network policy using the CLI You can delete a network policy in a namespace. Prerequisites You installed the OpenShift CLI ( oc ). You are working in the namespace where the network policy exists. Procedure To delete a network policy object, enter the following command: USD oc delete networkpolicy <policy_name> -n <namespace> where: <policy_name> Specifies the name of the network policy. <namespace> Optional: Specifies the namespace if the object is defined in a different namespace than the current namespace. Example output networkpolicy.networking.k8s.io/default-deny deleted 4.5. Viewing a network policy Use the following procedure to view a network policy for a namespace. 4.5.1. Viewing network policies using the CLI You can examine the network policies in a namespace. Prerequisites You installed the OpenShift CLI ( oc ). You are working in the namespace where the network policy exists. Procedure List network policies in a namespace: To view network policy objects defined in a namespace, enter the following command: USD oc get networkpolicy Optional: To examine a specific network policy, enter the following command: USD oc describe networkpolicy <policy_name> -n <namespace> where: <policy_name> Specifies the name of the network policy to inspect. <namespace> Optional: Specifies the namespace if the object is defined in a different namespace than the current namespace. For example: USD oc describe networkpolicy allow-same-namespace Output for oc describe command Name: allow-same-namespace Namespace: ns1 Created on: 2021-05-24 22:28:56 -0400 EDT Labels: <none> Annotations: <none> Spec: PodSelector: <none> (Allowing the specific traffic to all pods in this namespace) Allowing ingress traffic: To Port: <any> (traffic allowed to all ports) From: PodSelector: <none> Not affecting egress traffic Policy Types: Ingress

Commands:
kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: deny-by-default spec: podSelector: {} ingress: []
apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: allow-from-openshift-ingress spec: ingress: - from: - namespaceSelector: matchLabels: ingresscontroller.operator.openshift.io/deployment-ingresscontroller: default podSelector: {} policyTypes: - Ingress
kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: allow-same-namespace spec: podSelector: {} ingress: - from: - podSelector: {}
kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: allow-http-and-https spec: podSelector: matchLabels: role: frontend ingress: - ports: - protocol: TCP port: 80 - protocol: TCP port: 443
kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: allow-pod-and-namespace-both spec: podSelector: matchLabels: name: test-pods ingress: - from: - namespaceSelector: matchLabels: project: project_name podSelector: matchLabels: name: test-pods
apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: test-network-policy spec: podSelector: {} ingress: - from: - podSelector: matchLabels: role: frontend - from: - podSelector: matchLabels: role: backend
apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: test-network-policy spec: podSelector: {} ingress: - from: - podSelector: matchExpressions: - {key: role, operator: In, values: [frontend, backend]}
apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: policy1 spec: podSelector: matchLabels: role: db ingress: - from: - podSelector: matchLabels: role: frontend --- apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: policy2 spec: podSelector: matchLabels: role: client ingress: - from: - podSelector: matchLabels: role: frontend
apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: policy3 spec: podSelector: matchExpressions: - {key: role, operator: In, values: [db, client]} ingress: - from: - podSelector: matchLabels: role: frontend
kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: allow-27107 1 spec: podSelector: 2 matchLabels: app: mongodb ingress: - from: - podSelector: 3 matchLabels: app: app ports: 4 - protocol: TCP port: 27017
touch <policy_name>.yaml
kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: deny-by-default spec: podSelector: {} policyTypes: - Ingress ingress: []
kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: allow-same-namespace spec: podSelector: ingress: - from: - podSelector: {}
kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: allow-traffic-pod spec: podSelector: matchLabels: pod: pod-a policyTypes: - Ingress ingress: - from: - namespaceSelector: matchLabels: kubernetes.io/metadata.name: namespace-y
oc apply -f <policy_name>.yaml -n <namespace>
networkpolicy.networking.k8s.io/deny-by-default created
kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: deny-by-default namespace: default 1 spec: podSelector: {} 2 ingress: [] 3
oc apply -f deny-by-default.yaml
networkpolicy.networking.k8s.io/deny-by-default created
kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: web-allow-external namespace: default spec: policyTypes: - Ingress podSelector: matchLabels: app: web ingress: - {}
oc apply -f web-allow-external.yaml
networkpolicy.networking.k8s.io/web-allow-external created
kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: web-allow-all-namespaces namespace: default spec: podSelector: matchLabels: app: web 1 policyTypes: - Ingress ingress: - from: - namespaceSelector: {} 2
oc apply -f web-allow-all-namespaces.yaml
networkpolicy.networking.k8s.io/web-allow-all-namespaces created
oc run web --namespace=default --image=nginx --labels="app=web" --expose --port=80
oc run test-USDRANDOM --namespace=secondary --rm -i -t --image=alpine -- sh
wget -qO- --timeout=2 http://web.default
<!DOCTYPE html> <html> <head> <title>Welcome to nginx!</title> <style> html { color-scheme: light dark; } body { width: 35em; margin: 0 auto; font-family: Tahoma, Verdana, Arial, sans-serif; } </style> </head> <body> <h1>Welcome to nginx!</h1> <p>If you see this page, the nginx web server is successfully installed and working. Further configuration is required.</p> <p>For online documentation and support please refer to <a href="http://nginx.org/">nginx.org</a>.<br/> Commercial support is available at <a href="http://nginx.com/">nginx.com</a>.</p> <p><em>Thank you for using nginx.</em></p> </body> </html>
kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: web-allow-prod namespace: default spec: podSelector: matchLabels: app: web 1 policyTypes: - Ingress ingress: - from: - namespaceSelector: matchLabels: purpose: production 2
oc apply -f web-allow-prod.yaml
networkpolicy.networking.k8s.io/web-allow-prod created
oc run web --namespace=default --image=nginx --labels="app=web" --expose --port=80
oc create namespace prod
oc label namespace/prod purpose=production
oc create namespace dev
oc label namespace/dev purpose=testing
oc run test-USDRANDOM --namespace=dev --rm -i -t --image=alpine -- sh
wget -qO- --timeout=2 http://web.default
wget: download timed out
oc run test-USDRANDOM --namespace=prod --rm -i -t --image=alpine -- sh
wget -qO- --timeout=2 http://web.default
<!DOCTYPE html> <html> <head> <title>Welcome to nginx!</title> <style> html { color-scheme: light dark; } body { width: 35em; margin: 0 auto; font-family: Tahoma, Verdana, Arial, sans-serif; } </style> </head> <body> <h1>Welcome to nginx!</h1> <p>If you see this page, the nginx web server is successfully installed and working. Further configuration is required.</p> <p>For online documentation and support please refer to <a href="http://nginx.org/">nginx.org</a>.<br/> Commercial support is available at <a href="http://nginx.com/">nginx.com</a>.</p> <p><em>Thank you for using nginx.</em></p> </body> </html>
oc get networkpolicy
oc apply -n <namespace> -f <policy_file>.yaml
oc edit networkpolicy <policy_name> -n <namespace>
oc describe networkpolicy <policy_name> -n <namespace>
kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: allow-27107 1 spec: podSelector: 2 matchLabels: app: mongodb ingress: - from: - podSelector: 3 matchLabels: app: app ports: 4 - protocol: TCP port: 27017
oc delete networkpolicy <policy_name> -n <namespace>
networkpolicy.networking.k8s.io/default-deny deleted
oc get networkpolicy
oc describe networkpolicy <policy_name> -n <namespace>
oc describe networkpolicy allow-same-namespace
Name: allow-same-namespace Namespace: ns1 Created on: 2021-05-24 22:28:56 -0400 EDT Labels: <none> Annotations: <none> Spec: PodSelector: <none> (Allowing the specific traffic to all pods in this namespace) Allowing ingress traffic: To Port: <any> (traffic allowed to all ports) From: PodSelector: <none> Not affecting egress traffic Policy Types: Ingress