Context

When using environment variables in a Mattermost configuration that is uploaded and stored in the database, there are a few caveats to consider, particularly around using SAML/LDAP certs.

Documentation Request

Clarify caveats of using environment variables in a Mattermost configuration in cases where its uploaded and stored in the database, as detailed below.

Precedence: Environment variables take precedence over settings specified in the config.json file. If an environment variable is set that corresponds to a setting in the config.json file, the environment variable value will be used instead.
Persistence: Any changes made through the Mattermost System Console or API will update the configuration stored in the database. However, these changes will not affect the environment variables, which may still override these settings.
Security: Be cautious with sensitive information in environment variables. If someone gains access to the environment where Mattermost is running, they could potentially view sensitive environment variable values.
Deployment Consistency: When configurations are stored in the database, it might become harder to keep track of changes across different deployment environments (e.g., development, staging, production) if environment variables are not consistently managed.
Debugging: Troubleshooting configuration issues may be more complex because you need to check both the environment variables and the configuration stored in the database to understand the effective configuration.
Restart Required: Changes to environment variables require a restart of the Mattermost server to take effect, whereas changes made directly through the System Console or API do not necessarily require a restart.

SAML/LDAP Certificates

When configuring SAML or LDAP certificates in Mattermost, particularly while using environment variables and storing configuration in the database, there are some specific caveats to be aware of:

SAML Certificates

Certificate Paths: Ensure that the paths to the SAML certificates are correctly specified in your environment variables. Misconfiguration can lead to authentication failures.
Environment Variable Limits: Environment variables might have limits on the size of their content, which could be problematic if the certificates are large. It's generally better to store the path to the certificate rather than the certificate content itself.
Restart Required: Changes to the environment variables related to SAML configuration (like certificate paths) will require a restart of the Mattermost server.
Security: Ensure proper permissions on the certificate files to prevent unauthorized access. Storing certificates in environment variables should be done cautiously to avoid exposure.
Validity and Renewal: Keep track of the certificate validity periods to avoid unexpected authentication issues due to expired certificates. Ensure a smooth renewal process without downtime.

LDAP Certificates

Path and Permissions: Like SAML, ensure the paths to LDAP certificates are correctly specified in environment variables, and the files have proper permissions.
Size and Performance: If using large LDAP configurations, environment variable limits might become a bottleneck. Improperly set environment variables can degrade authentication performance.
Restart Required: Any modifications to LDAP-related environment variables require a Mattermost server restart to take effect.
Security: Treat LDAP certificates with the same security measures as SAML certificates. Make sure they are stored securely and access is restricted to authorized personnel.
Configuration Consistency: Ensure the LDAP configuration is consistent across different environments (development, staging, production) to avoid discrepancies in user authentication behavior.

General Tips:

Use Configuration Files for Certs: Where possible, consider using configuration files rather than environment variables to specify certificate-related settings. This makes managing large and sensitive data easier.
Monitor Logs: Always monitor the Mattermost server logs after making changes to SAML or LDAP configurations. This will help you quickly identify and resolve any issues related to certificate validation.
Backup Configurations: Keep backups of your configurations, including certificates, to quickly recover in case of accidental misconfigurations or failures.
Documentation: Maintain clear documentation of your SAML and LDAP configurations and their locations. This aids in troubleshooting and onboarding new team members.

Follow-up actions for Mattermost Documentation team

Include some cross-link to the information (i.e. Config in DB has to clarify how environment variables works here, and the environment variable documentation needs to link to, or mention, a caveat around how environment variables work with uploaded configuration

mattermost / docs

Help Wanted: Clarify environment variable behaviour with configuration that is uploaded (SAML/LDAP certs) #4131