Setting up Issuers¶
Before you can begin issuing certificates, you must configure at least one Issuer or ClusterIssuer resource in your cluster.
These represent a certificate authority from which signed x509 certificates can be obtained, such as Let’s Encrypt, or your own signing key pair stored in a Kubernetes Secret resource. They are referenced by Certificate resources in order to request certificates from them.
An Issuer is scoped to a single namespace, and can only fulfill Certificate resources within its own namespace. This is useful in a multi-tenant environment where multiple teams or independent parties operate within a single cluster.
Users often create
ClusterIssuers if they operate a
single-tenant environment and want to expose a cluster-wide mechanism for
obtaining TLS certificates from Let’s Encrypt.
Supported issuer types¶
cert-manager supports a number of different issuer backends, each with their own different types of configuration.
Please follow one of the below linked guides to learn how to set up the issuer types you require:
- CA - issue certificates signed by a X509 signing keypair, stored in a Secret in the Kubernetes API server.
- Self signed - issue self signed certificates.
- ACME - issue certificates obtained by performing challenge validations against an ACME server such as Let’s Encrypt.
- Vault- issue certificates from a Vault instance configured with the Vault PKI backend.
There are a few key things to know about Issuers, but for full information you can refer to the Issuer reference docs.
Difference between Issuers and ClusterIssuers¶
ClusterIssuers are a resource type similar to Issuers. They are specified in exactly the same way, but they do not belong to a single namespace and can be referenced by Certificate resources from multiple different namespaces.
They are particularly useful when you want to provide the ability to obtain certificates from a central authority (e.g. Letsencrypt, or your internal CA) and you run single-tenant clusters.
The resource spec is identical, and you should set the
certificate.spec.issuerRef.kind field to ClusterIssuer when creating your
- Setting up ACME Issuers
- Setting up CA Issuers
- Setting up self signing Issuers
- Setting up Vault Issuers