kubectl apply
Learn how to install cert-manager using kubectl and static manifests.
Prerequisites
- Install
kubectl
version>= v1.19.0
. (otherwise, you'll have issues updating the CRDs - see v0.16 upgrade notes) - Install a supported version of Kubernetes or OpenShift.
- Read Compatibility with Kubernetes Platform Providers if you are using Kubernetes on a cloud platform.
Steps
1. Install from the cert-manager release manifest
All resources (the CustomResourceDefinitions and the cert-manager, cainjector and webhook components) are included in a single YAML manifest file:
Install all cert-manager components:
kubectl apply -f https://github.com/cert-manager/cert-manager/releases/download/v1.15.3/cert-manager.yaml
By default, cert-manager will be installed into the cert-manager
namespace. It is possible to run cert-manager in a different namespace, although
you'll need to make modifications to the deployment manifests.
Once you've installed cert-manager, you can verify it is deployed correctly by
checking the cert-manager
namespace for running pods:
$ kubectl get pods --namespace cert-managerNAME READY STATUS RESTARTS AGEcert-manager-5c6866597-zw7kh 1/1 Running 0 2mcert-manager-cainjector-577f6d9fd7-tr77l 1/1 Running 0 2mcert-manager-webhook-787858fcdb-nlzsq 1/1 Running 0 2m
You should see the cert-manager
, cert-manager-cainjector
, and
cert-manager-webhook
pods in a Running
state. The webhook might take a
little longer to successfully provision than the others.
If you experience problems, first check the FAQ.
2. (optional) Wait for cert-manager webhook to be ready
The webhook component can take some time to start, and make the Kubernetes API server trust the webhook's certificate.
First, make sure that cmctl is installed.
cmctl performs a dry-run certificate creation check against the Kubernetes cluster.
If successful, the message The cert-manager API is ready
is displayed.
$ cmctl check apiThe cert-manager API is ready
The command can also be used to wait for the check to be successful. Here is an output example of running the command at the same time that cert-manager is being installed:
$ cmctl check api --wait=2mNot ready: the cert-manager CRDs are not yet installed on the Kubernetes API serverNot ready: the cert-manager CRDs are not yet installed on the Kubernetes API serverNot ready: the cert-manager webhook deployment is not ready yetNot ready: the cert-manager webhook deployment is not ready yetNot ready: the cert-manager webhook deployment is not ready yetNot ready: the cert-manager webhook deployment is not ready yetThe cert-manager API is ready
2. (optional) End-to-end verify the installation
Best way to fully verify the installation is to issue a test certificate. For this, we will create a self-signed issuer and a certificate resource in a test namespace.
cat <<EOF > test-resources.yamlapiVersion: v1kind: Namespacemetadata:name: cert-manager-test---apiVersion: cert-manager.io/v1kind: Issuermetadata:name: test-selfsignednamespace: cert-manager-testspec:selfSigned: {}---apiVersion: cert-manager.io/v1kind: Certificatemetadata:name: selfsigned-certnamespace: cert-manager-testspec:dnsNames:- example.comsecretName: selfsigned-cert-tlsissuerRef:name: test-selfsignedEOF
Create the test resources.
kubectl apply -f test-resources.yaml
Check the status of the newly created certificate. You may need to wait a few seconds before cert-manager processes the certificate request.
$ kubectl describe certificate -n cert-manager-test...Spec:Common Name: example.comIssuer Ref:Name: test-selfsignedSecret Name: selfsigned-cert-tlsStatus:Conditions:Last Transition Time: 2019-01-29T17:34:30ZMessage: Certificate is up to date and has not expiredReason: ReadyStatus: TrueType: ReadyNot After: 2019-04-29T17:34:29ZEvents:Type Reason Age From Message---- ------ ---- ---- -------Normal CertIssued 4s cert-manager Certificate issued successfully
Clean up the test resources.
kubectl delete -f test-resources.yaml
If all the above steps have completed without error, you're good to go!
Uninstalling
Warning: To uninstall cert-manager you should always use the same process for installing but in reverse. Deviating from the following process whether cert-manager has been installed from static manifests or Helm can cause issues and potentially broken states. Please ensure you follow the below steps when uninstalling to prevent this happening.
Before continuing, ensure that unwanted cert-manager resources that have been created by users have been deleted. You can check for any existing resources with the following command:
kubectl get Issuers,ClusterIssuers,Certificates,CertificateRequests,Orders,Challenges --all-namespaces
It is recommended that you delete all these resources before uninstalling cert-manager.
If you plan on reinstalling later and don't want to lose some custom resources, you can keep them.
However, this can potentially lead to problems with finalizers. Some resources, like
Challenges
, should be deleted to avoid getting stuck in a pending state.
Once the unneeded resources have been deleted, you are ready to uninstall cert-manager using the procedure determined by how you installed.
Warning: Uninstalling cert-manager or simply deleting a
Certificate
resource can result in TLSSecret
s being deleted if they havemetadata.ownerReferences
set by cert-manager. You can control whether owner references are added toSecret
s using the--enable-certificate-owner-ref
controller flag. By default, this flag is set to false, which means that no owner references are added. However, in cert-manager v1.8 and older, changing the flag's value from true to false did not result in existing owner references being removed. This behavior was fixed in cert-manager v1.8. Do check the owner references to confirm that they actually are removed.
Uninstalling with regular manifests
Uninstalling from an installation with regular manifests is a case of running
the installation process, in reverse, using the delete command of kubectl
.
Delete the installation manifests using a link to your currently running version
vX.Y.Z
like so:
Warning: This command will also remove installed cert-manager CRDs. All cert-manager resources (e.g.
certificates.cert-manager.io
resources) will be removed by Kubernetes' garbage collector. You cannot keep any custom resources if you delete theCustomResourceDefinition
s. If you want to keep resources, you should manageCustomResourceDefinition
s separately.
kubectl delete -f https://github.com/cert-manager/cert-manager/releases/download/vX.Y.Z/cert-manager.yaml
Namespace Stuck in Terminating State
If the namespace has been marked for deletion without deleting the cert-manager
installation first, the namespace may become stuck in a terminating state. This
is typically due to the fact that the APIService
resource still exists
however the webhook is no longer running so is no longer reachable. To resolve
this, ensure you have run the above commands correctly, and if you're still
experiencing issues then run:
kubectl delete apiservice v1beta1.webhook.cert-manager.io
Deleting pending challenges
Challenge
s can get stuck in a pending state when the finalizer is unable to complete
and Kubernetes is waiting for the cert-manager controller to finish.
This happens when the controller is no longer running to remove the flag,
and the resources are defined as needing to wait.
You can fix this problem by doing what the controller does manually.
First, delete existing cert-manager webhook configurations, if any:
kubectl delete mutatingwebhookconfigurations cert-manager-webhookkubectl delete validatingwebhookconfigurations cert-manager-webhook
Then change the .metadata.finalizers
field to an empty list by editing the challenge resource:
kubectl edit challenge <the-challenge>