# kelseyhightower/kube-cert-manager

Manage Lets Encrypt certificates for a Kubernetes cluster.

Repository: https://github.com/kelseyhightower/kube-cert-manager
Canonical: https://ross.abutalabs.com/products/kube-cert-manager
Language: Go
License: Apache-2.0
License Family: permissive
Last push: 2018-01-25T12:41:32+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 3697, "days_push": 3142, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1110, forks 136 (observed 2026-08-28T04:03:37.521874+00:00)

## What it is
A Kubernetes controller that automatically manages Let's Encrypt TLS certificates, storing them as Kubernetes secrets via ACME dns-01 challenges. It uses ThirdParty Resources to declare certificates and supports multiple DNS providers through exec plugins.

## Use cases
- automatically provision lets encrypt certificates in kubernetes
- manage tls secrets for kubernetes ingress load balancers
- renew acme certificates with dns-01 challenges
- secure web apps on kubernetes with free certificates
- learn how to write custom kubernetes controllers

## When to choose
- you run an older Kubernetes cluster (1.3+) and want automated Let's Encrypt certs via dns-01
- you need TLS secrets for any TLS-terminating load balancer in Kubernetes
- you want a reference implementation for building custom Kubernetes controllers

## When to avoid
- you need an actively maintained solution - the project hasn't released since 2018
- you need http-01 validation or modern cert-manager features
- you run a recent Kubernetes version where ThirdParty Resources are replaced by CRDs

## Facets
- artifact type: service
- maturity: abandoned
- function: security, deployment, container-orchestration, configuration-management
- domain: security, self-hosted
- platform: go, cloud, self-hosted
- tags: lets-encrypt, acme, tls-certificates, dns-01, kubernetes-controller, cert-manager, containers, devops, kubernetes, docker

## Member repositories
- kelseyhightower/kube-cert-manager (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:37.521874+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 2026-08-30T06:43:27.441107+00:00, confidence not recorded.
  - readme: https://github.com/kelseyhightower/kube-cert-manager (fetched 2026-08-28T04:03:37.521874+00:00, sha a67ed24818d9)
- Data as of 2026-08-30T08:39:29.467469+00:00.