Appliance category: 


Self-hosted Slack compatible team messaging

Mattermost is a sleek Slack-compatible open source service that makes it easy to self-host team communications. It brings messaging and file sharing into one place, accessible across PCs and mobile, with archiving and search. It integrates with a range of apps out-of-the-box and is extendable so you can build custom functionality on top of the Golang / React core.

Stable version: 18.0 (changelog)

This appliance includes all the standard features in TurnKey Core, and on top of that:

  • Mattermost configurations:
    • Mattermost installed from upstream source code to /opt/mattermost

      Security note: Updates to Mattermost may require supervision so they ARE NOT configured to install automatically. See below for updating Mattermost.

    • Includes Nginx (webserver); pre-configured to proxy Mattermost.
    • Pre-configured to use PostgreSQL (recommended for production).
  • SSL support out of the box.
  • Adminer administration frontend for PostgreSQL (listening on port 12322 - uses SSL).
  • Postfix MTA (bound to localhost) to allow sending of email (e.g., password recovery).
  • Webmin modules for configuring Postfix, PostgreSQL.

Supervised Manual Mattermost Update

Note: Check the Mattermost docs to ensure that upgrading your current version to the latest is supported. Always ensure that you have a tested backup before proceeding with software updates.

See the Official Mattermost docs for instructions on how to update.

Mattermost does not have a security only newsletter so we recommend that you subcribe to the Mattermost Newsletter to keep up to date.

Usage details & Logging in for Administration

No default passwords: For security reasons there are no default passwords. All passwords are set at system initialization time.

Ignore SSL browser warning: browsers don't like self-signed SSL certificates, but this is the only kind that can be generated automatically without paying a commercial Certificate Authority.

Web - point your browser at either:

  1. - not encrypted so no browser warning
  2. - encrypted with self-signed SSL certificate

Web - point your browser at either:

  1. - not encrypted so no browser warning
  2. - encrypted with self-signed SSL certificate

Username for database administration:

Login as PostgreSQL username postgres at

  1. - Adminer database management web app
  2. PostgreSQL command line tool:
    $ psql -U postgres -h localhost
    Password for user postgres:
    Type "help" for help.

Username for OS system administration:

Login as root except on AWS marketplace which uses username admin.

  1. Point your browser to:
  2. Login with SSH client:
    ssh root@

    Special case for AWS marketplace:

    ssh admin@

* Replace with a valid IP or hostname.