https://DevOpsCloud.io -- Cloud Monk Losang Jinpa, Ph.D., MCSE/MCT, GitOps DevOps Engineer

Cert-Manager is a Kubernetes-native tool that automates the management and issuance of TLS certificates within a Kubernetes cluster. It leverages Kubernetes Custom Resource Definitions (CRDs) to define certificate requests and manage the lifecycle of certificates, including issuance, renewal, and revocation.

• **Kubernetes Custom Resources:** Employs familiar Kubernetes manifests to request and manage TLS certificates.
• **Certificate Issuance and Renewal:** Automates the process of obtaining and renewing TLS certificates from various certificate authorities (CAs), including Let's Encrypt, HashiCorp Vault, and Venafi.
• **Certificate Lifecycle Management:** Handles the entire lifecycle of certificates, including issuance, renewal, and revocation.
• **Integration with Ingress Controllers:** Seamlessly integrates with popular Ingress controllers like Nginx Ingress Controller and Traefik to automatically provision and manage TLS certificates for incoming traffic.
• **Support for Multiple Issuers:** Allows you to configure multiple certificate issuers to provide flexibility and redundancy.
• **Webhook Support:** Enables integration with custom webhooks for advanced certificate management scenarios.

• **Simplified Certificate Management:** Automates the complex process of obtaining, renewing, and managing TLS certificates in Kubernetes.
• **Improved Security:** Enhances the security of your Kubernetes applications and services by ensuring they have valid and up-to-date TLS certificates.
• **Reduced Operational Overhead:** Eliminates the manual effort required to manage TLS certificates, freeing up your team to focus on other tasks.
• **Open Source:** Cert-Manager is an open-source project under the Apache 2.0 License.

• **Installation:** Install Cert-Manager using Helm or by applying the necessary manifests directly to your Kubernetes cluster.
• **Configuration:** Define Certificate resources to request TLS certificates and Issuer resources to configure certificate authorities.
• **Integration:** Integrate Cert-Manager with your Ingress controller or other Kubernetes resources to automatically provision and manage TLS certificates.

1. **Certificate Definition:**

```yaml apiVersion: cert-manager.io/v1 kind: Certificate metadata:

 name: my-certificate

 secretName: my-certificate-tls  # Name of the secret to store the certificate
 issuerRef:
   name: letsencrypt-prod  # Name of the Issuer resource
   kind: ClusterIssuer
 commonName: www.example.com
 dnsNames:
 - www.example.com

This configuration defines a Certificate resource that requests a certificate for “[www.example.com](https://www.example.com)” from the “letsencrypt-prod” ClusterIssuer. The issued certificate will be stored in a Secret named “my-certificate-tls.”

2. **Issuer Definition (for Let's Encrypt):**

```yaml apiVersion: cert-manager.io/v1 kind: ClusterIssuer metadata:

 name: letsencrypt-prod

 acme:
   server: https://acme-v02.api.letsencrypt.org/directory
   email: admin@example.com
   privateKeySecretRef:
     name: letsencrypt-prod
   solvers:
   - http01:
       ingress:
         class: nginx

This configuration defines a ClusterIssuer that uses Let's Encrypt's ACME protocol to issue certificates. It specifies the ACME server URL, the email address for notifications, and the solver to use for domain validation (in this case, HTTP-01 challenge using the “nginx” ingress class).

• **Cert-Manager Official Website:** s://cert-manager.io/(https://cert-manager.io/)
• **Cert-Manager GitHub Repository:** s://github.com/cert-manager/cert-manager(https://github.com/cert-manager/cert-manager)
• **Cert-Manager Documentation:** s://cert-manager.io/docs/(https://cert-manager.io/docs/)

• **GitHub Repository:** * s://github.com/cert-manager/cert-manager(https://github.com/cert-manager/cert-manager)
• **Official Documentation:** * s://cert-manager.io/docs/(https://cert-manager.io/docs/)