Best Practices: Network Policies

Best Practices: Network Policies.md

Aspect	Description
Isolate Namespaces, Pods, and Services	Use network policies to block all incoming and outgoing traffic by default, and then create additional policies to allow specific types of traffic
Enforce Security Policies	Create network policies that follow organizational security standards or comply with regulatory requirements
Implement Micro-Segmentation and Zero Trust Networking	Use network policies to restrict communication between microservices or verify the identities and authorizations of pods before allowing traffic
Group Pods and Services Based on Labels	Use labels like "app" (e.g., frontend or backend) or "name" (e.g., dev or prod) to categorize pods and services, and create network policies that match these labels
Specify Traffic Types Using Ports and Protocols	Define which types of traffic are allowed or denied using ports (e.g., TCP on port 80 or 443) or protocols (e.g., UDP on port 53)
Block Specific IP Addresses or Ranges	Restrict traffic from certain IP ranges or individual addresses using CIDR notation (e.g., 10.0.0.0/8 or 192.168.0.0/16)
Allow Only From Specific Namespaces	Apply network policies to specific namespaces using selectors (e.g., default or kube-system), and deny traffic from others (e.g., kube-public or kube-node-lease)
Default Deny-All Policy	Establish a default deny-all policy that blocks all traffic, and then add specific allow rules for essential connections
Flexible and Scalable Policies	Avoid hard-coding IP addresses or port numbers by grouping pods and namespaces using labels and selectors
Troubleshooting and Debugging Tools	Utilize tools like kubectl, Calicoctl, or NetworkPolicyStats to identify issues or optimize policies
Regular Reviews and Updates	Periodically review and modify network policies to maintain consistency, effectiveness, and prevent conflicts or errors