# kubernetes-sigs/controller-runtime

Repo for the controller-runtime subproject of kubebuilder (sig-apimachinery)

Repository: https://github.com/kubernetes-sigs/controller-runtime
Canonical: https://ross.abutalabs.com/products/controller-runtime
Language: Go
License: Apache-2.0
License Family: permissive
Topics: k8s-sig-api-machinery
Last push: 2026-08-25T06:31:10+00:00

## Health v2 (maintenance only)
Score: 94/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 83, longevity 100
- inputs: {"age_days": 3009, "days_push": 8, "days_rel": 113, "gap_med": 11.5, "n_releases_24m": 27}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2946, forks 1305 (observed 2026-08-28T04:07:31.195447+00:00)

## What it is
A set of Go libraries for building Kubernetes controllers and operators, providing a manager, controller, builder, and client abstractions on top of client-go. It is the runtime layer leveraged by Kubebuilder and Operator SDK.

## Use cases
- write a kubernetes operator in go
- build a custom controller for a CRD
- reconcile custom resources in a k8s cluster
- scaffold a kubebuilder project runtime
- watch and react to kubernetes resource events
- implement the operator pattern for my app

## When to choose
- you are writing Kubernetes controllers or operators in Go
- you use Kubebuilder or Operator SDK and need the underlying runtime
- you want managed informers, caches, and reconciliation loops instead of raw client-go

## When to avoid
- you only need to query the Kubernetes API without a reconcile loop - use client-go directly
- you are writing operators in a non-Go language
- you need a one-off script rather than a long-running controller

## Facets
- artifact type: library
- maturity: active
- function: concurrency, developer-tools, sdk
- domain: cloud-computing, infrastructure-as-code, developer-tools, microservices
- platform: go, cross-platform
- tags: kubernetes-operators, controllers, reconciliation, kubebuilder, operator-sdk, api-machinery, containers, kubernetes, linux

## Member repositories
- kubernetes-sigs/controller-runtime (main) score 94

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:31.195447+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T07:32:47.843860+00:00, confidence not recorded.
  - readme: https://github.com/kubernetes-sigs/controller-runtime (fetched 2026-08-28T04:07:31.195447+00:00, sha e445ce5f8730)
- Data as of 2026-08-30T08:39:29.467469+00:00.