Configuration in the Mattermost Database

A new configuration option was added in 5.10 release to use the database as the single source of truth for the active configuration of your Mattermost installation. This will change the Mattermost binary from reading the default config.json file to reading the configuration settings stored within a configuration table in the database.

Mattermost has been running our community server on this option since the feature was released, and recommends its use for those on High Availability deployments.

Benefits to using this option:

  • Conveniently manage configuration changes directly from the System Console, even in High Availability deployments and read-only containerized environments.
  • Ensure all servers in a High Availability deployment have the same configuration, even when new servers are added to the cluster.
  • Automatically deploy SAML certificates and keys to all servers in the cluster.

To start using configuration in database, pass the database connection string via the --config flag or MM_CONFIG environment variable. For example:

To migrate an existing config.json into the database, use the config migrate command. For example:

Any existing SAML certificates and private keys will also be migrated to the database.

With configuration in the database enabled, any changes to the configuration are recorded to the Configurations and ConfigurationFiles tables. Furthermore, ClusterSettings.ReadOnlyConfig is ignored, enabling full use of the System Console.

Note that environment variable overrides remain fully supported using the configuration in the database, allowing per-server customization as required. A long standing bug has also been fixed, ensuring environment variables are no longer written back to the configuration when other changes are made.

Troubleshooting

Server fails to start

Providing the –disableconfigwatch flag while not actually pointing at a file will fail to start the server with an appropriate error message.