Comparison
Custom resourcevsOperator
Custom resource
your team's own object type — a queue, a tenant, an environment — is created the same way as anything else and reconciled by your own controller.
An extension that adds a new object type to the orchestrator's API, so your abstractions get the same storage, validation, access control and tooling as the built-in ones. It is how a platform team turns 'raise a ticket for a new environment' into a file in a repository. It is also how a platform team accidentally builds a bespoke API nobody outside the team can operate, so the bar for adding one should be genuinely high.
Full entry →Operator
the failover, the backup and the version upgrade for the database are performed by software encoding what the DBA used to do.
A custom controller that manages a stateful application, encoding the operational knowledge for it — how to bootstrap, back up, scale, and upgrade safely — as a reconciliation loop. It exists because generic orchestration handles stateless workloads well and stateful ones badly. The trade is real: you swap a runbook a human follows for software that will act at 3am, and now the quality of that operator is your database's reliability.
Full entry →