prometheus-alertmanager is a free and open-source alert handling component for Prometheus. Part of the Prometheus ecosystem, Alertmanager handles alerts sent by Prometheus server and routes them to receivers like email, Slack, or PagerDuty

Hardware Requirements:

CPU: 1 core minimum

RAM: 128MB minimum (512MB+ recommended)

Storage: 1GB for data

Network: HTTP API access

Operating System:

Linux: Any modern distribution (RHEL, Debian, Ubuntu, CentOS, Fedora, Arch, Alpine, openSUSE)

macOS: 10.14+ (Mojave or newer)

Windows: Windows Server 2016+ or Windows 10

FreeBSD: 11.0+

Network Requirements:

Port 9093 (default prometheus-alertmanager port)

Port 9094 for cluster peers

Dependencies:

See official documentation for specific requirements

System Access: root or sudo privileges required

This guide supports installation on:

RHEL 8/9 and derivatives (CentOS Stream, Rocky Linux, AlmaLinux)

Debian 11/12

Ubuntu 20.04/22.04/24.04 LTS

Arch Linux (rolling release)

Alpine Linux 3.18+

openSUSE Leap 15.5+ / Tumbleweed

SUSE Linux Enterprise Server (SLES) 15+

macOS 12+ (Monterey and later)

FreeBSD 13+

Windows 10/11/Server 2019+ (where applicable)

bash

# Install EPEL repository if needed
sudo dnf install -y epel-release

# Install prometheus-alertmanager
sudo dnf install -y alertmanager

# Enable and start service
sudo systemctl enable --now alertmanager

# Configure firewall
sudo firewall-cmd --permanent --add-port=9093/tcp
sudo firewall-cmd --reload

# Verify installation
alertmanager --version

bash

# Update package index
sudo apt update

# Install prometheus-alertmanager
sudo apt install -y alertmanager

# Enable and start service
sudo systemctl enable --now alertmanager

# Configure firewall
sudo ufw allow 9093

# Verify installation
alertmanager --version

bash

# Install prometheus-alertmanager
sudo pacman -S alertmanager

# Enable and start service
sudo systemctl enable --now alertmanager

# Verify installation
alertmanager --version

bash

# Install prometheus-alertmanager
apk add --no-cache alertmanager

# Enable and start service
rc-update add alertmanager default
rc-service alertmanager start

# Verify installation
alertmanager --version

bash

# Install prometheus-alertmanager
sudo zypper install -y alertmanager

# Enable and start service
sudo systemctl enable --now alertmanager

# Configure firewall
sudo firewall-cmd --permanent --add-port=9093/tcp
sudo firewall-cmd --reload

# Verify installation
alertmanager --version

bash

# Using Homebrew
brew install alertmanager

# Start service
brew services start alertmanager

# Verify installation
alertmanager --version

bash

# Using pkg
pkg install alertmanager

# Enable in rc.conf
echo 'alertmanager_enable="YES"' >> /etc/rc.conf

# Start service
service alertmanager start

# Verify installation
alertmanager --version

bash

# Using Chocolatey
choco install alertmanager

# Or using Scoop
scoop install alertmanager

# Verify installation
alertmanager --version

bash

# Create configuration directory
sudo mkdir -p /etc/alertmanager

# Set up basic configuration
# See official documentation for detailed configuration options

# Test configuration
alertmanager --version

bash

# Enable service
sudo systemctl enable alertmanager

# Start service
sudo systemctl start alertmanager

# Stop service
sudo systemctl stop alertmanager

# Restart service
sudo systemctl restart alertmanager

# Check status
sudo systemctl status alertmanager

# View logs
sudo journalctl -u alertmanager -f

bash

# Enable service
rc-update add alertmanager default

# Start service
rc-service alertmanager start

# Stop service
rc-service alertmanager stop

# Restart service
rc-service alertmanager restart

# Check status
rc-service alertmanager status

bash

# Enable in /etc/rc.conf
echo 'alertmanager_enable="YES"' >> /etc/rc.conf

# Start service
service alertmanager start

# Stop service
service alertmanager stop

# Restart service
service alertmanager restart

# Check status
service alertmanager status

bash

# Using Homebrew services
brew services start alertmanager
brew services stop alertmanager
brew services restart alertmanager

# Check status
brew services list | grep alertmanager

powershell

# Start service
net start alertmanager

# Stop service
net stop alertmanager

# Using PowerShell
Start-Service alertmanager
Stop-Service alertmanager
Restart-Service alertmanager

# Check status
Get-Service alertmanager

See the official documentation for advanced configuration options.

nginx

upstream alertmanager_backend {
    server 127.0.0.1:9093;
}

server {
    listen 80;
    server_name alertmanager.example.com;
    return 301 https://$server_name$request_uri;
}

server {
    listen 443 ssl http2;
    server_name alertmanager.example.com;

    ssl_certificate /etc/ssl/certs/alertmanager.example.com.crt;
    ssl_certificate_key /etc/ssl/private/alertmanager.example.com.key;

    location / {
        proxy_pass http://alertmanager_backend;
        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;
    }
}

apache

<VirtualHost *:80>
    ServerName alertmanager.example.com
    Redirect permanent / https://alertmanager.example.com/
</VirtualHost>

<VirtualHost *:443>
    ServerName alertmanager.example.com
    
    SSLEngine on
    SSLCertificateFile /etc/ssl/certs/alertmanager.example.com.crt
    SSLCertificateKeyFile /etc/ssl/private/alertmanager.example.com.key
    
    ProxyRequests Off
    ProxyPreserveHost On
    
    ProxyPass / http://127.0.0.1:9093/
    ProxyPassReverse / http://127.0.0.1:9093/
</VirtualHost>

haproxy

frontend alertmanager_frontend
    bind *:80
    bind *:443 ssl crt /etc/ssl/certs/alertmanager.pem
    redirect scheme https if !{ ssl_fc }
    default_backend alertmanager_backend

backend alertmanager_backend
    balance roundrobin
    server alertmanager1 127.0.0.1:9093 check

bash

# Set appropriate permissions
sudo chown -R alertmanager:alertmanager /etc/alertmanager
sudo chmod 750 /etc/alertmanager

# Configure firewall
sudo firewall-cmd --permanent --add-port=9093/tcp
sudo firewall-cmd --reload

# Enable SELinux policies (if applicable)
sudo setsebool -P httpd_can_network_connect on

See official documentation for database configuration requirements.

bash

# Basic system tuning
echo 'net.core.somaxconn = 65535' | sudo tee -a /etc/sysctl.conf
echo 'net.ipv4.tcp_max_syn_backlog = 65535' | sudo tee -a /etc/sysctl.conf
sudo sysctl -p

bash

# Check service status
sudo systemctl status alertmanager

# View logs
sudo journalctl -u alertmanager -f

# Monitor resource usage
top -p $(pgrep alertmanager)

bash

#!/bin/bash
# Basic backup script
BACKUP_DIR="/backup/alertmanager"
DATE=$(date +%Y%m%d_%H%M%S)

mkdir -p "$BACKUP_DIR"
tar -czf "$BACKUP_DIR/alertmanager-backup-$DATE.tar.gz" /etc/alertmanager /var/lib/alertmanager

echo "Backup completed: $BACKUP_DIR/alertmanager-backup-$DATE.tar.gz"

bash

# Stop service
sudo systemctl stop alertmanager

# Restore from backup
tar -xzf /backup/alertmanager/alertmanager-backup-*.tar.gz -C /

# Start service
sudo systemctl start alertmanager

1. Service won't start:

bash

# Check logs
sudo journalctl -u alertmanager -n 100
sudo tail -f /var/log/alertmanager/alertmanager.log

# Check configuration
alertmanager --version

# Check permissions
ls -la /etc/alertmanager

2. Connection issues:

bash

# Check if service is listening
sudo ss -tlnp | grep 9093

# Test connectivity
telnet localhost 9093

# Check firewall
sudo firewall-cmd --list-all

3. Performance issues:

bash

# Check resource usage
top -p $(pgrep alertmanager)

# Check disk I/O
iotop -p $(pgrep alertmanager)

# Check connections
ss -an | grep 9093

yaml

version: '3.8'
services:
  alertmanager:
    image: alertmanager:latest
    ports:
      - "9093:9093"
    volumes:
      - ./config:/etc/alertmanager
      - ./data:/var/lib/alertmanager
    restart: unless-stopped

Maintenance

bash

# RHEL/CentOS/Rocky/AlmaLinux
sudo dnf update alertmanager

# Debian/Ubuntu
sudo apt update && sudo apt upgrade alertmanager

# Arch Linux
sudo pacman -Syu alertmanager

# Alpine Linux
apk update && apk upgrade alertmanager

# openSUSE
sudo zypper update alertmanager

# FreeBSD
pkg update && pkg upgrade alertmanager

# Always backup before updates
tar -czf /backup/alertmanager-pre-update-$(date +%Y%m%d).tar.gz /etc/alertmanager

# Restart after updates
sudo systemctl restart alertmanager

Regular Maintenance

bash

# Log rotation
sudo logrotate -f /etc/logrotate.d/alertmanager

# Clean old logs
find /var/log/alertmanager -name "*.log" -mtime +30 -delete

# Check disk usage
du -sh /var/lib/alertmanager

Official Documentation: https://docs.alertmanager.org/

GitHub Repository: https://github.com/alertmanager/alertmanager

Community Forum: https://forum.alertmanager.org/

Best Practices Guide: https://docs.alertmanager.org/best-practices

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Note: This guide is part of the HowToMgr collection. Always refer to official documentation for the most up-to-date information.

Alerting

prometheus-alertmanager Installation Guide