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MySQL TLS/SSL Encryption

Prerequisite : To configure TLS/SSL in MySQL, KubeDB uses cert-manager to issue certificates. So first you have to make sure that the cluster has cert-manager installed. To install cert-manager in your cluster following steps here.

To issue a certificate, the following cr of cert-manager is used:

• Issuer/ClusterIssuer: Issuers and ClusterIssuers represent certificate authorities (CAs) that are able to generate signed certificates by honoring certificate signing requests. All cert-manager certificates require a referenced issuer that is in a ready condition to attempt to honor the request. You can learn more details here.

• Certificate: cert-manager has the concept of Certificates that define the desired x509 certificate which will be renewed and kept up to date. You can learn more details here.

MySQL CRD Specification:

KubeDB uses the following cr fields to enable SSL/TLS encryption in MySQL.

• spec:
  • requireSSL
  • tls:
    • issuerRef
    • certificates

Read about the fields in details from mysql concept,

When, requireSSL is set, the users must specify the tls.issuerRef field. KubeDB uses the issuer or clusterIssuer referenced in the tls.issuerRef field, and the certificate specs provided in tls.certificate to generate certificate secrets using Issuer/ClusterIssuers specification. These certificates secrets including ca.crt, tls.crt and tls.key etc. are used to configure MySQL server, exporter etc. respectively.

How TLS/SSL configures in MySQL

The following figure shows how KubeDB enterprise is used to configure TLS/SSL in MySQL. Open the image in a new tab to see the enlarged version.

Deploying MySQL with TLS/SSL configuration process consists of the following steps:

1. At first, a user creates an Issuer/ClusterIssuer cr.

2. Then the user creates a MySQL cr.

3. KubeDB community operator watches for the MySQL cr.

4. When it finds one, it creates Secret, Service, etc. for the MySQL database.

5. KubeDB enterprise operator watches for MySQL(5c), Issuer/ClusterIssuer(5b), Secret and Service(5a).

6. When it finds all the resources(MySQL, Issuer/ClusterIssuer, Secret, Service), it creates Certificates by using tls.issuerRef and tls.certificates field specification from MySQL cr.

7. cert-manager watches for certificates.

8. When it finds one, it creates certificate secrets tls-secrets(server, client, exporter secrets, etc.) that hold the actual self-signed certificate.

9. KubeDB community operator watches for the Certificate secrets tls-secrets.

10. When it finds all the tls-secret, it creates a StatefulSet so that MySQL server is configured with TLS/SSL.

In the next doc, we are going to show a step by step guide on how to configure a MySQL database with TLS/SSL.