The vocabulary.
WHAT A CLUSTER IS
A set of machines managed together.
WHAT THE CONTROL PLANE DOES
Holds the desired state and makes decisions.
WHAT A NODE IS
A machine running workloads.
WHAT A POD IS
The smallest unit scheduled: one or more containers sharing a network address and storage.
WHY SEVERAL CONTAINERS IN ONE POD
For helpers that must run alongside the main container.
WHAT THAT PATTERN IS CALLED
A sidecar.
WHAT A DEPLOYMENT DOES
Maintains a stated number of identical pods, and handles updates.
WHAT A SERVICE DOES
Gives a stable name and address for a set of pods.
WHY IT IS NECESSARY
Pods are replaced constantly, and their addresses change.
WHAT AN INGRESS DOES
Routes external traffic to services, by hostname and path.
WHAT A CONFIGMAP HOLDS
Non-secret configuration.
WHAT A SECRET HOLDS
Credentials, encoded and ideally encrypted at rest.
WHAT A NAMESPACE PROVIDES
A logical division within a cluster.
WHAT A STATEFULSET IS FOR
Workloads needing stable identity and storage, such as databases.
WHAT A JOB IS FOR
Work that runs to completion.
WHAT A DAEMONSET IS FOR
One pod per node, for agents.
WHAT TO LEARN FIRST
Pods, deployments and services.
