Tool cheatsheet

Kubernetes manifests Cheatsheet

YAML for the Kubernetes resources you write most: Deployments, Services, Ingress, config, storage, probes, scaling and access control.

Workloads

Deployment — Run three replicas of a container and roll out updates gradually.
Set resource requests and limits — Request what a container needs for scheduling, and cap what it can use.
Add health probes — Use readiness to control traffic and liveness to restart a stuck container.
Pass configuration as environment variables — Load a ConfigMap and read one key from a Secret into environment variables.
Harden a container — Run as a non-root user with a read-only filesystem and no extra privileges.
Run setup before the app starts — Run a container to completion before the main containers start.
Job — Run a task to completion, retrying on failure.
CronJob — Run a Job on a schedule. This one runs daily at 02:00.

Service (internal) — Give pods a stable internal address and spread traffic across them.
Service (public load balancer) — Ask the cloud provider for an external load balancer.
Ingress with TLS — Route a host name to a Service and terminate TLS with a certificate Secret.
Deny all ingress traffic by default — Block all incoming traffic to pods in a namespace, then allow what you need.

Namespace — Create a namespace to group resources.
ConfigMap — Store non-secret configuration.
Secret — Store sensitive values. stringData accepts plain text, which Kubernetes encodes. Secrets are only base64-encoded unless you enable encryption at rest.
PersistentVolumeClaim — Request storage that outlives a pod.
Mount a volume — Mount a claim into a container.

Autoscale on CPU — Scale a Deployment between 2 and 10 replicas to keep CPU near 70%. Needs metrics-server.
PodDisruptionBudget — Keep at least two pods available during voluntary disruptions such as node drains.
ServiceAccount — Give pods an identity for API access.
Role and RoleBinding — Allow a service account to read pods in one namespace.
Schedule onto matching nodes — Require nodes with a label, and tolerate a taint.

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