How do you implement blue-green deployments in Kubernetes?

Blue-green deployment is a technique that reduces downtime by running two identical production environments and switching traffic between them.\n\nImplementation Strategy:\n• Blue: Current production version\n• Green: New version being deployed\n• Switch traffic atomically using services\n• Rollback quickly if issues occur\n\nKubernetes Implementation:\n1. Deploy green environment alongside blue\n2. Test green environment thoroughly\n3. Update service selector to point to green\n4. Monitor and validate\n5. Decommission blue environment\n\nExample Service Switch:\n# Switch from blue to green\nkubectl patch service myapp -p "{\"spec\":{\"selector\":{\"version\":\"green\"}}}"\n\n# Rollback to blue if needed\nkubectl patch service myapp -p "{\"spec\":{\"selector\":{\"version\":\"blue\"}}}"\n\nAdvantages:\n• Zero-downtime deployments\n• Instant rollback capability\n• Full testing before switch\n• Reduced risk\n\nBest Practices:\n• Automate the switching process\n• Implement comprehensive monitoring\n• Use feature flags for gradual rollout\n• Maintain database compatibility