# Flink Kube Operator

Kubernetes operator that manages the lifecycle of Apache Flink jobs via CRDs.

## Language

**FlinkJob**:
A Kubernetes Custom Resource representing a desired Flink job. Contains spec (desired state) and status (observed state).
_Avoid_: Job CR, CRD instance

**ManagedJob**:
Runtime wrapper that drives a FlinkJob's lifecycle through its state machine (init → run → savepoint → upgrade).
_Avoid_: Job controller, job runner

**jarRef**:
Full OCI reference identifying a JAR artifact in a registry (e.g. `registry.io/org/app:1.0.0`).
_Avoid_: jarUri, jar URL, artifact URL

**jarDigest**:
SHA256 content hash of the JAR layer in the OCI manifest. Immutable identifier for the artifact bytes.
_Avoid_: content hash, checksum

**pullSecret**:
A `kubernetes.io/dockerconfigjson` Kubernetes Secret containing registry credentials, referenced by name in the FlinkJob spec.
_Avoid_: imagePullSecret, registry secret

**JarFile**:
Ephemeral artifact handle — a downloaded/pulled JAR on local disk awaiting upload to Flink, then deleted.
_Avoid_: temp jar, local jar

**LifeCycleStatus**:
Operator-managed lifecycle state of a FlinkJob (HEALTHY, RESTORING, GRACEFULLY_PAUSED, FAILED, etc.).
_Avoid_: operator status, lifecycle state

**JobStatus**:
Flink-reported job state (RUNNING, FAILED, FINISHED, etc.). Mirrored from the Flink REST API.
_Avoid_: flink status, job state

**Savepoint**:
A consistent snapshot of a Flink job's state, used for restart and upgrade.
_Avoid_: checkpoint, snapshot