Awesome Open Source
Awesome Open Source

Build Status Go Report Card
Artifact Hub


cert-manager is a Kubernetes add-on to automate the management and issuance of TLS certificates from various issuing sources.

It will ensure certificates are valid and up to date periodically, and attempt to renew certificates at an appropriate time before expiry.

It is loosely based upon the work of kube-lego and has borrowed some wisdom from other similar projects e.g. kube-cert-manager.

cert-manager high level overview diagram


Documentation for cert-manager can be found at Please make sure to select the correct version of the documentation to view on the top right of the page.

Issues and PRs towards the documentation should be filed in the website repo.

For the common use-case of automatically issuing TLS certificates to Ingress resources, aka a kube-lego replacement, see the cert-manager nginx ingress quick start guide.

See Installation within the documentation for installation instructions.


If you encounter any issues whilst using cert-manager, we have a number of places you can use to try and get help.

First of all we recommend looking at the troubleshooting guide of our documentation.

The quickest way to ask a question is to first post on our Slack channel (#cert-manager) on the Kubernetes Slack. There are a lot of community members in this channel, and you can often get an answer to your question straight away!

You can also try searching for an existing issue. Properly searching for an existing issue will help reduce the number of duplicates, and help you find the answer you are looking for quicker.

Please also make sure to read through the relevant pages in the documentation before opening an issue. You can also search the documentation using the search box on the top left of the page.

If you believe you have encountered a bug, and cannot find an existing issue similar to your own, you may open a new issue. Please be sure to include as much information as possible about your environment.


The cert-manager-dev Google Group is used for project wide announcements and development coordination. Anybody can join the group by visiting here and clicking "Join Group". A Google account is required to join the group.

Bi-weekly Development Meeting

Once you've joined the cert-manager-dev Google Group, you should receive an invite to the bi-weekly development meeting, hosted every other Wednesday at 5pm London time on Google Meet.

Anyone is welcome to join these calls, even if just to ask questions. Meeting notes are recorded in Google docs.

Daily Standups

You are also welcome to join our daily standup every weekday at 10.30am London time on Google Meet. For more information, see


We welcome pull requests with open arms! There's a lot of work to do here, and we're especially concerned with ensuring the longevity and reliability of the project.

Please take a look at our issue tracker if you are unsure where to start with getting involved!

We also use the #cert-manager and #cert-manager-dev channels on Kubernetes Slack for chat relating to the project.

Developer documentation is available on the website.

Coding Conventions

Code style guidelines are documented on the coding conventions page of the cert-manager website. Please try to follow those guidelines if you're submitting a pull request for cert-manager.

Importing cert-manager as a Module

⚠️ Please note that cert-manager does not currently provide a Go module compatibility guarantee. That means that most code under pkg/ is subject to change in a breaking way, even between minor or patch releases and even if the code is currently publicly exported.

This lack of a Go module compatibility guarantee does not affect API version guarantees under the Kubernetes Deprecation Policy.

Security Reporting

Security is the number one priority for cert-manager. If you think you've found a security vulnerability, we'd love to hear from you.

Please follow the instructions in to report a vulnerability to the team.


The list of releases is the best place to look for information on changes between releases.

Logo design by Zoe Paterson

Get A Weekly Email With Trending Projects For These Topics
No Spam. Unsubscribe easily at any time.
Go (198,511
Hacktoberfest (37,988
Kubernetes (11,925
Tls (990
Certificate (912
Letsencrypt (912
Crd (111
Related Projects