Quartz 4

cert-manager

3 min read

🛡️ Cert-Manager: SSL Certificates Management in Kubernetes

Cert-Manager is a powerful tool for automating the management of ssl-certs within Kubernetes clusters. This guide provides an overview of Cert-Manager’s features, focuses on self-signed certificate creation, and addresses common troubleshooting issues.

🔍 Overview

Info

Cert-Manager is an SSL certificates management tool that automates the creation, renewal, and management of SSL certificates within a Kubernetes environment.

  • Product Type: SSL Certificates Manager

  • Focus: Automating SSL certificate creation, renewal, and management within Kubernetes.

  • Key Uses: Automating SSL certificates management, including creation, renewal, and troubleshooting in Kubernetes clusters.

🧠 Key Features of Cert-Manager

Cert-Manager offers a range of features for managing SSL certificates in Kubernetes:

🧑‍💻 SSL Certificate Automation

Tip

Cert-Manager automates the creation, renewal, and management of SSL certificates in a Kubernetes environment, reducing manual work.

🛠️ Multiple Issuer Support

Info

Cert-Manager supports different types of issuers, including self-signed certificates, internal CA certificates, and external certificate authorities, offering flexibility in certificate management.

🗂️ Customizable Issuer Configuration

Tip

You can configure the Issuer and ClusterIssuer resources to manage certificates based on different policies and certificate authorities, providing control over your certificate management process.

🌍 Certificate Challenges

Warning

Cert-Manager supports different types of challenges like HTTP-01, DNS-01, and more to validate the ownership of domain names for certificate issuance.

📊 Certificate Renewal

Info

Cert-Manager automatically renews certificates before they expire, ensuring continuous SSL protection without manual intervention.

🌍 Explore More

For further reading and detailed guides, check out the official Cert-Manager documentation: Cert-Manager Docs.

🚨 Common Issues and Troubleshooting

🧩 Self-Signed Certificates Creation

Option 1: Upload Existing CA.key and CA.crt Files

  1. Create a Self-Signed CA

    • Generate the private key (ca.key):

      openssl genrsa -out ca.key 4096

    • Generate the certificate (ca.crt):

      openssl req -new -x509 -sha256 -days 365 -key ca.key -out ca.crt

  2. Convert the Files to Base64 String

    • Use base64 to encode the ca.key and ca.crt files:

      cat ca.key | base64 -w 0

  3. Create SSL Secret Object

    • Create a Kubernetes Secret with the base64-decoded values:

      apiVersion: v1
kind: Secret
metadata:
  name: ssl-issuer-secret
type: Opaque
data:
  tls.crt: <base64-decoded-string>
  tls.key: <base64-decoded-string>

  4. Create the ClusterIssuer or Issuer Object

    • Use the Secret to configure a ClusterIssuer:

      apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  name: selfsigned-issuer
spec:
  ca:
    secretName: ssl-issuer-secret

Option 2: Create CA Through Cert-Manager

  1. Create the ClusterIssuer or Issuer Object Using the selfSigned Attribute

    • Use Cert-Manager’s built-in functionality to create a self-signed certificate:

      apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  name: root-issuer
spec:
  selfSigned: {}

⚠️ Common Errors and Solutions

DNS Record Not Yet Propagated

Error

Error: Waiting for DNS-01 challenge propagation: DNS record for "your-dns-record" not yet propagated.
Cause: DNS records (TXT records) may not have propagated yet, which is required for Cert-Manager to issue the certificate.
Solution: Configure DNS to use external resolvers:

```yaml
extraArgs:
  - --dns01-recursive-nameservers-only
  - --dns01-recursive-nameservers=8.8.8.8:53,1.1.1.1:53
```

No Solver Found

Error

Error: Failed to determine a valid solver configuration for the set of domains on the Order: no configured challenge solvers can be used for this challenge
Cause: Missing or misconfigured solver settings for handling the DNS challenge.
Solution: Ensure that the dnsZones in your solver configuration match the DNS hostnames zone.

📚 Further Information

For more in-depth guides, configuration details, and troubleshooting tips, refer to the official Cert-Manager documentation:

🔁 Related Resources

Info

🏷️ Tags

cert-manager
ssl-certs
kubernetes
self-signed-certificates
dns
network-security
kubernetes-management
certificate-automation
tls-certs

Graph View