Mattermost is an open-source, self-hosted messaging platform designed for team collaboration. It is a great alternative to Slack and is widely used for secure communication. This guide will walk you through installing Mattermost on Ubuntu, Debian, AlmaLinux, and Rocky Linux.

Prerequisites

Before installing Mattermost, ensure you have the following:

• A server running Ubuntu 22.04/20.04, Debian 11/10, AlmaLinux 9/8, or Rocky Linux 9/8.

• Root or sudo access.

• A PostgreSQL database.

• At least 4GB of RAM and 2 CPUs.

Step 1: Update Your System

Update your package lists and upgrade installed packages:

sudo apt update && sudo apt upgrade -y  # For Ubuntu/Debian
sudo dnf update -y  # For AlmaLinux/Rocky

Step 2: Install Required Packages

Install PostgreSQL and other dependencies:

# For Ubuntu/Debian
sudo apt install postgresql postgresql-contrib wget -y

# For AlmaLinux/Rocky
sudo dnf install postgresql-server postgresql-contrib wget -y

Initialize and start PostgreSQL:

sudo systemctl enable --now postgresql

Create a database and user for Mattermost:

sudo -u postgres psql
CREATE DATABASE mattermost;
CREATE USER mmuser WITH PASSWORD 'secure_password';
GRANT ALL PRIVILEGES ON DATABASE mattermost TO mmuser;
\q

Step 3: Download and Set Up Mattermost

Navigate to the /opt directory and download Mattermost:

cd /opt
wget https://releases.mattermost.com/9.0/mattermost-9.0-linux-amd64.tar.gz
sudo tar -xvzf mattermost-9.0-linux-amd64.tar.gz
sudo mv mattermost /opt/mattermost

Create a storage directory:

sudo mkdir /opt/mattermost/data

Set correct permissions:

sudo chown -R mattermost:mattermost /opt/mattermost
sudo chmod -R 755 /opt/mattermost

Step 4: Configure Mattermost

Edit the configuration file:

sudo nano /opt/mattermost/config/config.json

Modify the database settings:

"DriverName": "postgres",
"DataSource": "postgres://mmuser:secure_password@localhost/mattermost?sslmode=disable",

Save and exit.

Step 5: Create a Systemd Service

Create a new service file:

sudo nano /etc/systemd/system/mattermost.service

Add the following content:

[Unit]
Description=Mattermost
After=network.target postgresql.service

[Service]
Type=simple
ExecStart=/opt/mattermost/bin/mattermost
WorkingDirectory=/opt/mattermost
User=mattermost
Group=mattermost
Restart=always
RestartSec=10
LimitNOFILE=49152

[Install]
WantedBy=multi-user.target

Enable and start Mattermost:

sudo systemctl daemon-reload
sudo systemctl enable --now mattermost

Step 6: Configure Reverse Proxy with Nginx

Install Nginx:

sudo apt install nginx -y  # Ubuntu/Debian
sudo dnf install nginx -y  # AlmaLinux/Rocky

Create a new Nginx configuration file:

sudo nano /etc/nginx/conf.d/mattermost.conf

Add the following content:

server {
    listen 80;
    server_name your-domain.com;

    location / {
        proxy_pass http://localhost:8065/;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}

Restart Nginx:

sudo systemctl restart nginx

Step 7: Finalize Mattermost Setup

1. Open your browser and visit http://your-domain.com.

2. Create an admin account and configure your workspace.

3. Start using Mattermost!

Conclusion

You have successfully installed Mattermost on Ubuntu, Debian, AlmaLinux, or Rocky Linux. To enhance security, enable SSL with Let’s Encrypt and configure a firewall.