cert-manager is a tool that automates certificate management. This can be integrated with Istio gateways to manage TLS certificates.
Consult the cert-manager installation documentation to get started. No special changes are needed to work with Istio.
cert-manager can be used to write a secret to Kubernetes, which can then be referenced by a Gateway. To get started, configure a
Certificate resource, following the cert-manager documentation. The
Certificate should be created in the same namespace as the
istio-ingressgateway deployment. For example, a
Certificate may look like:
apiVersion: cert-manager.io/v1 kind: Certificate metadata: name: ingress-cert namespace: istio-system spec: secretName: ingress-cert commonName: my.example.com dnsNames: - my.example.com ...
Once we have the certificate created, we should see the secret created in the
istio-system namespace. This can then be referenced in the
tls config for a Gateway under
apiVersion: networking.istio.io/v1alpha3 kind: Gateway metadata: name: gateway spec: selector: istio: ingressgateway servers: - port: number: 443 name: https protocol: HTTPS tls: mode: SIMPLE credentialName: ingress-cert # This should match the Certificate secretName hosts: - my.example.com # This should match a DNS name in the Certificate
cert-manager provides direct integration with Kubernetes Ingress by configuring an annotation on the Ingress object. If this method is used, the Ingress must reside in the same namespace as the
istio-ingressgateway deployment, as secrets will only be read within the same namespace.
Certificate can be created as described in Istio Gateway, then referenced in the
apiVersion: networking.k8s.io/v1beta1 Kind: Ingress metadata: name: ingress annotations: kubernetes.io/ingress.class: istio spec: rules: - host: my.example.com http: ... tls: - hosts: - my.example.com # This should match a DNS name in the Certificate secretName: ingress-cert # This should match the Certificate secretName