Prometheus Installation Guide

Prometheus is an open-source systems monitoring and alerting toolkit. It collects and stores metrics as time series data, with rich query language and alerting capabilities.

Prerequisites

• A system running Linux, macOS, or Windows
• Administrative/sudo privileges
• Terminal/Command Prompt access
• Docker (optional, for containerized installation)
• Sufficient disk space (recommended: 50GB+)
• Internet connection for downloading packages

Installation Instructions

# Create Prometheus system user
sudo useradd --no-create-home --shell /bin/false prometheus
 
# Create directories
sudo mkdir /etc/prometheus
sudo mkdir /var/lib/prometheus
 
# Download Prometheus
wget https://github.com/prometheus/prometheus/releases/download/v2.45.0/prometheus-2.45.0.linux-amd64.tar.gz
 
# Extract and move files
tar xvf prometheus-*.tar.gz
cd prometheus-*/
sudo cp prometheus /usr/local/bin/
sudo cp promtool /usr/local/bin/
sudo cp -r consoles/ /etc/prometheus
sudo cp -r console_libraries/ /etc/prometheus
 
# Configure Prometheus
sudo tee /etc/prometheus/prometheus.yml << EOF
global:
scrape_interval: 15s
 
scrape_configs:
- job_name: 'prometheus'
static_configs:
  - targets: ['localhost:9090']
EOF
 
# Create systemd service
sudo tee /etc/systemd/system/prometheus.service << EOF
[Unit]
Description=Prometheus
Wants=network-online.target
After=network-online.target
 
[Service]
User=prometheus
Group=prometheus
Type=simple
ExecStart=/usr/local/bin/prometheus \
--config.file /etc/prometheus/prometheus.yml \
--storage.tsdb.path /var/lib/prometheus/ \
--web.console.templates=/etc/prometheus/consoles \
--web.console.libraries=/etc/prometheus/console_libraries
 
[Install]
WantedBy=multi-user.target
EOF
 
# Set permissions
sudo chown -R prometheus:prometheus /etc/prometheus
sudo chown -R prometheus:prometheus /var/lib/prometheus
 
# Start Prometheus
sudo systemctl daemon-reload
sudo systemctl start prometheus
sudo systemctl enable prometheus

Post-Installation Configuration

Basic Configuration File (prometheus.yml)

global:
  scrape_interval: 15s
  evaluation_interval: 15s
 
rule_files:
  # - "first.rules"
  # - "second.rules"
 
scrape_configs:
  - job_name: prometheus
    static_configs:
      - targets: ['localhost:9090']
 
  - job_name: node
    static_configs:
      - targets: ['localhost:9100']

Adding Node Exporter

# Install Node Exporter (Ubuntu/Debian)
wget https://github.com/prometheus/node_exporter/releases/download/v1.6.0/node_exporter-1.6.0.linux-amd64.tar.gz
tar xvf node_exporter-*.tar.gz
sudo cp node_exporter-*/node_exporter /usr/local/bin
sudo useradd -rs /bin/false node_exporter
 
# Create systemd service for Node Exporter
sudo tee /etc/systemd/system/node_exporter.service << EOF
[Unit]
Description=Node Exporter
After=network.target
 
[Service]
User=node_exporter
Group=node_exporter
Type=simple
ExecStart=/usr/local/bin/node_exporter
 
[Install]
WantedBy=multi-user.target
EOF
 
# Start Node Exporter
sudo systemctl daemon-reload
sudo systemctl start node_exporter
sudo systemctl enable node_exporter

Verification

Verify the installation by:

1. Checking the Prometheus service status:

sudo systemctl status prometheus

2. Accessing the Prometheus web interface:

http://localhost:9090

3. Verifying metrics collection:

http://localhost:9090/metrics

Common Configuration Options

Setting Up Basic Authentication

1. Create password file:

sudo apt install apache2-utils
sudo htpasswd -c /etc/prometheus/.htpasswd admin

2. Update Prometheus configuration:

web:
  basic_auth_users:
    admin: <hashed-password>

Configuring Retention

Update the Prometheus service file with retention settings:

ExecStart=/usr/local/bin/prometheus \
    --storage.tsdb.retention.time=15d \
    --storage.tsdb.retention.size=50GB

Troubleshooting

Common Issues

1. Service Won't Start

   • Check logs: sudo journalctl -u prometheus
   • Verify permissions on data directory
   • Validate configuration file syntax

2. Cannot Scrape Targets

   • Check firewall settings
   • Verify target endpoints are accessible
   • Check network connectivity

3. High Memory Usage

   • Adjust retention period
   • Review query patterns
   • Consider federation or remote storage

Security Considerations

1. Use HTTPS for web interface
2. Implement authentication
3. Use secure passwords and rotate regularly
4. Restrict network access
5. Keep Prometheus and exporters updated
6. Use minimal permissions for service accounts

Additional Resources

• Official Prometheus Documentation
• Prometheus Best Practices
• PromQL Tutorial
• Alerting Rules