guideSQL Databases

# Requirements

SQL database, used by the CKEditor Collaboration Server needs to meet software and hardware requirements presented in the database requirements article.

# Supported SQL databases

The following databases are currently supported:

  • MySQL in version 5.7 (minimal supported version) or 8.0 (recommended)
  • PostgreSQL in version 12

# Driver selection

By default, the MySQL database driver is used.
It can be changed by using the DATABASE_DRIVER environmental variables.

Currently, two options are supported:

  • mysql - MySQL (default)
  • postgres - PostgreSQL

# Connection and basic credentials

To connect to the database at least the DATABASE_HOST needs to be set.
It is highly recommended to change the default values of the DATABASE_USER and DATABASE_PASSWORD variables.

DATABASE_HOST                            - required
DATABASE_PORT                            - optional (default: 3306)
DATABASE_USER                            - optional (default: "root")
DATABASE_PASSWORD                        - optional (default: "password")
DATABASE_DATABASE                        - optional (default: "cs-on-premises")
DATABASE_SCHEMA                          - optional (default: "cs-on-premises", used for Postgres driver)

# TLS connection and certificates

  • If your database server is configured to require SSL connections, you can use DATABASE_SSL_CA, DATABASE_SSL_KEY and DATABASE_SSL_CERT to pass certificates to the database driver.
  • If your database server is configured to require SSL connections and the certificate of the database server is signed by a trusted third party, you can set DATABASE_SSL_ENABLE to true instead of passing the certificates.
DATABASE_SSL_ENABLE                      - optional (default: false)
DATABASE_SSL_CA                          - optional
DATABASE_SSL_KEY                         - optional
DATABASE_SSL_CERT                        - optional

You can provide the certificates in two ways:

# Passing certificates as files

To pass the certificate as a file you need to provide the path to it, which is available inside of the application container.

DATABASE_SSL_CA: /path/to/certificate/server-certificate.pem

It may require configuring volumes, to make the certificate available under the path provided to the DATABASE_SSL_CA variable.

# Passing certificates as text

Another way of providing the required certificates is by providing them as text.


The DATABASE_SSL_CERT can be provided in three formats:

  • as a one-liner, where new lines should be represented by a newline character (\n).
  • in the original certificate format using the Literal Block Scalar character (|).
  • as a base64 encoded string. It could solve problems related to newline character encoding by cloud hosting platforms.

# Root certificates rotation

Various cloud providers e.g. Azure, AWS rotate their root certificates periodically, it may require manual certificate updates by the system administrator to keep the application up and running.

Read a detailed article about the case in the Azure documentation

# MySQL High availability

To ensure high availability of MySQL, we recommend using MySQL Master-Slave Replication with one active master. You can find more information about MySQL replication here.

We recommend using one master because the data in the application is modified quickly and it is often the case that the data between nodes is not synchronized due to replication lag.

In case of a failure, the application will not automatically switch between the nodes, so it is worth looking into a load balancer that will automatically turn the connection between the nodes.

# Next steps