Configure TLS

KOTS-based installation

PostgreSQL

To configure TLS for an external PostgreSQL, you have the following configuration options:

PostgreSQL TLS mode: PostgreSQL server supports the following TLS mode:
- Allow: first try an SSL connection; if that fails, try a non-SSL connection.
- Require: only try an SSL connection. If a root Certificate Authority file is present, verify the certificate in the same way as if Verify Certificate Authority was specified.
- Verify Certificate Authority: only try an SSL connection, and verify that the server certificate is issued by a trusted certificate authority (CA).
- Verify Certificate Authority and Hostname: only try an SSL connection, and verify that the server certificate is issued by a trusted CA and that the requested server hostname matches that in the certificate.
Custom certificate authority: custom certificate authority to use to authenticate PostgreSQL server identity.
Client authentication required: PostgreSQL server configured to authenticate a client.
PostgreSQL client TLS key.
PostgreSQL client TLS certificate.

To disable TLS configuration, you should first set "Postgres TLS mode" to Allow in the Admin Console and deploy the configuration. Then you can disable TLS on the PostgreSQL server. Finally, disable the TLS configuration within the Admin Console.

Redis

To configure TLS for Redis, you have the following configuration options:

Require Redis server authentication: force the application to require the Redis server to authenticate with a valid certificate. By checking this setting, you can provide a custom certificate authority to validate the Redis server certificate.
Client authentication required: if the Redis server is configured to require client authentication, you need to check this box and provide:
- a TLS key,
- a TLS certificate.

For scaling recommendations, refer to the hardware requirements documentation.

Helm-based installation

With Helm-based installations, instead of parameters being set in the console, they should be put in a YAML file served at installation. There are 2 methods for handling certificates, but in both cases:

For PostgreSQL, set postgresql.tls.mode to the SSL mode of your choice among disable, allow, prefer, require, verify-ca, and verify-full
For Redis, set redis.tls.requireServerCert to true if you wish to require a Redis server certificate check.

Certificates as a secret

This is the preferred method.

Create a Kubernetes secret containing your custom certificate authority, TLS certificate and key.

kubectl create secret generic custom-ca-secret-name \
--from-file /path/to/pg-tls-key \
--from-file /path/to/pg-tls-cert \
--from-file /path/to/ca-cert

Reference this secret in the YAML file under (postgresql|redis).existingSecret
Specify the keys used in the secret under (postgresql|redis).existingSecretKeys.tls.(crt|key|caCrt)

The file should look like this extract:

postgresql:
  tls:
    # Possible values: disable, allow, prefer, require, verify-ca, verify-full
    mode: require
  existingSecret: "my-secret"
  existingSecretKeys:
    tls:
      crt: "pg_client.crt"
      key: "pg_client.key"
      caCrt: "pg_server.ca_crt"
      
redis:
  main:
    tls:
      requireServerCert: true
    existingSecret: "my-secret"
    existingSecretKeys:
      tls:
        crt: "redis_client.crt"
        key: "redis_client.key"
        caCrt: "redis_server.ca_crt"

Certificates inline

Add the certificates inline under (postgresql|redis).tls.(crt|key|caCrt)

The file should look like this extract:

postgresql:
  tls:
    # Possible values: disable, allow, prefer, require, verify-ca, verify-full
    mode: require
    crt: |
      -----BEGIN CERTIFICATE-----
      My certificate
      -----END CERTIFICATE-----
    key: |
      -----BEGIN RSA PRIVATE KEY-----
      My key
      -----END RSA PRIVATE KEY-----
    caCrt: |
      -----BEGIN CERTIFICATE-----
      My CA certificate
      -----END CERTIFICATE-----
      
redis:
  main:
    tls:
      requireServerCert: true
      crt: |
        -----BEGIN CERTIFICATE-----
        My certificate
        -----END CERTIFICATE-----
      key: |
        -----BEGIN RSA PRIVATE KEY-----
        My key
        -----END RSA PRIVATE KEY-----
      caCrt: |
        -----BEGIN CERTIFICATE-----
        My CA certificate
        -----END CERTIFICATE-----