Kubernetes Design Patterns and Anti-Patterns

[arun-gupta]

Let's list Kubernetes design patterns here:

• Create a cluster with odd number of masters
• Homogeneous cluster?
• Use Docker images with a specific version instead of latest tag
• For HA, spread masters and workers across multiple AZ in a region
• Never use Pod directly, wrap it in a Deployment (this will create ReplicaSet)
• Instead of federation, create multiple clusters and use CI/CD pipeline to deploy across those multiple clusters

Anti-patterns

• Federated cluster

[dalbhanj]

Design pattern - have regular backups of your etcd cluster state?

[dalbhanj]

Design pattern - Evaluate HA for your clusters and applications and follow appropriate upgrade process (in-place or blue/green)

[christopherhein]

@dalbhanj do you consider backups of etcd cluster state an anti-pattern or design pattern?

[christopherhein]

add design practices: imperative vs declarative object management.

https://kubernetes.io/docs/tutorials/object-management-kubectl/object-management/

[Raffo]

For users, I would also consider discussing the number of replicas in a deployment. It happened to us that someone was using deployments with only one replica... and then complained about their application not being available. We usually recommend minimum 3 when they are interested in HA.