Release Notes

Release v1.5.0

Major Themes

API Deprecation

The recent Kubernetes 1.22 release has removed a number of deprecated APIs. You can read the official blog post Kubernetes API and Feature Removals In 1.22 to learn more about it. If you intend to upgrade to Kubernetes 1.22, you must upgrade to cert-manager 1.5.

To keep compatibility with older Kubernetes versions (down to 1.16), cert-manager 1.5 is now compatible with both Ingress v1 and v1beta1. cert-manager will default to using v1 Ingress, and fall back to v1beta1 when v1 is not available.

Additionally, the cert-manager API versions v1alpha2, v1alpha3 and v1beta1 are now deprecated, and will be removed in cert-manager 1.7. Please change all your YAML manifests that use a deprecated API version to use cert-manager.io/v1 instead, and re-apply them.

These deprecation changes have been implemented in the cert-manager PRs #4225 and #4172.

Experimental Features

Features that we are currently working on are included in cert-manager releases but disabled by default, as they are likely to change in future. If any of them look interesting to you, please try them out and report bugs or quirks in a GitHub Issue.

Gateway API

We have seen many requests from users to support different ways of routing HTTP traffic into their clusters for solving ACME HTTP-01 challenges. As the cloud-native ecosystem has so many different ingress implementations, we searched for a solution that would avoid having to add individual support for every kind of virtual service to the cert-manager API, and settled on the sig-network Gateway API.

The Gateway API project aims to provide a universal API for modeling service networking in Kubernetes, and while it is still in its alpha stages is already gaining wide adoption. By supporting the Gateway API HTTPRoute resource, we hope that anyone using Ambassador, Contour, Gloo, HAProxy, Istio, Kong or Traefik will be able to solve HTTP-01 challenges, with more implementations coming in future.

To go along with the HTTPRoute resource support, we have also added a gateway-shim controller that will allow users to annotate their Gateway resources to get a cert-manager Certificate automatically created, similar to the current ingress-shim functionality.

Implemented in the cert-manager PRs #4276 and #4158.

CertificateSigningRequests

CertificateSigningRequest is a built-in Kubernetes resource that was originally aimed at requesting X.509 client certificates and serving certificates for Kubernetes components such as kubelet.

We have seen a rising interest in using the CertificateSigningRequest (CSR) resource as a way to provision workload certificates in service meshes such as Istio and its Istio Custom CA Integration using Kubernetes CSR. For that purpose, the CSR resource needs to be integrated with existing signers such as HashiCorp Vault or Venafi TPP.

Back in cert-manager 1.4, the CA Issuer became the first built-in cert-manager issuer to support signing CertificateSigningRequest resources. In 1.5, we extended the support to all existing Issuers.

The support for signing CSR resources is still experimental and requires to be explicitly enabled. If you are interested, please take a look at the Kubernetes CertificateSigningRequest documentation on the cert-manager website.

To help you try the CSR support, you may want to try a new command that was added to the kubectl plugin. It allows you to create a CSR resource out of a cert-manager Certificate manifest:

kubectl cert-manager x create certificatesigningrequest example-csr certificate.yaml

Finally, we decided to remove the annotation experimental.cert-manager.io/ca that was added to the CertificateSigningRequest resource after being signed by cert-manager. This annotation was introduced in cert-manager 1.4 and will no longer be set on CertificateSigningRequest resources. We removed this annotation due to a technical limitation related to the fact that Kubernetes resources have a status subresource that is separate from the main resource.

The above features were implemented in the cert-manager PRs #4112, #4100, #4103, #4108, #4106, and #4143

User Experience

kubectl plugin

cert-manager comes with a kubectl plugin, kubectl cert-manager, that comes in handy for checking the status of your cert-manager Certificate resources.

In 1.5, a new experimental command for installing cert-manager has been added. Under the hood, it uses the cert-manager Helm chart. This means that all helm templating options are also supported by this install command:

kubectl cert-manager x install \
  --set prometheus.enabled=false \  # Example: disabling prometheus using a Helm parameter
  --set webhook.timeoutSeconds=4s   # Example: changing the wehbook timeout using a Helm parameter

An interesting feature that comes when using with this new install command is that it installs the CRDs in a way that prevents helm uninstall from deleting the CRDs while uninstalling cert-manager.

The plugin is now capable of determining when your cert-manager deployment is ready to be used:

kubectl cert-manager check api

The plugin also learned how to discover the version of cert-manager running on your cluster, similar to kubectl version:

kubectl cert-manager version

To install the plugin, check out the Kubectl plugin page on the cert-manager website.

These features were implemented by Tim in the cert-manager PRs #4226, #4205, and #4138.

Helm chart

While installing cert-manager using Helm, you might have noticed that the --wait flag does not wait until cert-manager is fully functional.

With 1.5, the --wait flag now works as you would expect. The Helm chart now comes with a small startup job that waits until the cert-manager API becomes ready.

Implemented in the cert-manager PR #4234 by Tim.

Labels and annotations on generated Secret and CertificateRequest resources

cert-manager now allows you to add custom annotations and labels to the Secret containing the TLS key pair using the new Certificate field secretTemplate. This is useful when using third-party solutions such as kubed to copy Secret resources to multiple namespaces. The secretTemplate is synced to the Secret when the Certificate is created or renewed.

Here is an example of Certificate using the secretTemplate field:

apiVersion: cert-manager.io/v1
kind: Certificate
spec:
  secretTemplate:
    annotations:
      my-secret-annotation: "foo"
    labels:
      my-secret-label: bar

Note that labels and annotations can only be added or replaced, but not removed. Removing any labels or annotations from the template or removing the template itself will have no effect.

Along with the ability to set your own annotations and labels on Secret resources created by cert-manager, you can also tell cert-manager which annotations should be copied from Certificate resources to the generated CertificateRequest resources. By default, cert-manager will skip copying the annotations with the following prefixes:

• kubectl.kubernetes.io/,
• fluxcd.io,
• argocd.argoproj.io.

If you wish to keep the old behavior and allow all annotations to be copied, you can pass the flag --copied-annotations=* to the cert-manager controller.

Implemented in the cert-manager PRs #3828 and #4251.

Community

This is the first time that cert-manager participated in Google Summer of Code. Congratulations to Arsh and Tim for completing their GSoC projects! We hope you both continue to contribute in future.

Thanks again to all open-source contributors with commits in this release:

• alrs
• annerajb
• Dean-Coakley
• francescsanjuanmrf
• inteon
• jonathansp
• kit837
• longkai
• mozz-lx
• RinkiyaKeDad
• tamalsaha
• thiscantbeserious
• ulrichgi
• wpjunior

Also thanks to coderanger for helping people out on the Slack #cert-manager channel; it’s a huge help and much appreciated.

New Features

• cert-manager now supports using Ed25519 private keys and signatures for Certificates. Implemented in the cert-manager PR #4079.
• cert-manager now emits an event when a CertificateSigningRequest resource has not yet been approved. Without this event, the user would never know that cert-manager is waiting for the approval of the CertificateSigningRequest resource. Implemented in the cert-manager PR #4229.
• cert-manager now only supports the version v1 of the AdmissionReviewVersion and ConversionReviewVersion resources, both available since Kubernetes 1.16. The v1beta1 version is no longer supported by cert-manager. This change was implemented in the cert-manager PRs #4254 and #4253.
• cert-manager now restarts more quickly by clearing the leader election before shutting down. Also, upon shutdown, the controller loops now cleanly stop, which allows all in-flight reconciliation functions to finish before exiting. Implemented in the cert-manager PR #4243.
• Metrics: a new metric, named clock_time_seconds was added; this metric allows for monitoring systems that do not have a built-in time function (e.g. DataDog) to calculate the number of seconds until a certificate expires by subtracting this metric from the existing certificate_expiration_timestamp metrics. Implemented in the cert-manager PR #4105.
• Helm chart: the Prometheus scraping service port now has a name. Implemented in the cert-manager PR #4072.
• Helm chart: you can now configure the labels for the cert-manager-webhook service using the Helm value webhook.serviceLabels. Implemented in the cert-manager PR #4260.

Bug or Regression

• Security: cert-manager now times out after 10 second when performing the self-check while solving HTTP-01 challenges. Fixed in the cert-manager PR #4311.
• Cloudflare: Refactored DNS01 challenge to use API for finding the nearest Zone (fixing potential DNS issues) (#4147, @thiscantbeserious)
• Fix a bug where failed CertificateRequest resources were not retried (#4130, @irbekrm)
• Fix a regression that would lead to a Certificate becoming “Failed” when the issued X.509 certificate’s subject DN would be equal to the issuer’s subject DN. Fixed in the cert-manager PR #4237.
• Fix a regression where the tls.crt certificate chain would unexpectedly not contain an intermediate CA certificate when no root CA is available in the CA chain returned by the issuer. This bug affected the Vault Issuer, Venafi Issuer and CA Issuer. This bug was fixed in the cert-manager PR #4261.
• Fix a goroutine leak that was causing the controller’s memory usage to grow with time. Fixed in the cert-manager PR #4233.
• Fix a race condition introduced in cert-manager 0.15 that would crash cert-manager for clusters with a large number of certificates. Fixed in the cert-manager PR #4231.
• Fix a bug where the default renewal duration of certificate, set to 30 days, would clash with the duration of certificates issued by the Vault Issuer. All Certificate resources are now renewed 2/3 through the duration unless a custom renew period is specified by setting renewBefore on the Certificate. Fixed in the cert-manager PR #4092.
• The cert-manager binaries, including the kubectl plugin, now exit with the correct exit code on SIGINT (Ctrl+C) and SIGTERM events. More specifically, when one of these events is caught, cert-manager will exit with the code 128 + signal number. Fixed in #4230.
• The static manifests available on the GitHub Releases page now contain a version label app.kubernetes.io/version: v1.5.0. We also removed the Helm-specific labels from the static manifests. Fixed in the cert-manager PR #4190.

Other (Cleanup or Flake)

• A conformance end-to-end testing suite was added for the CertificateSigningRequest resources (#4101).
• Reduce binary sizes from 74MB down to 49MB by adding the Go ldflag -w (#4181).