Install and configure Prometheus on Debian 10/11

Prometheus is a free and open source monitoring system that allows you to collect time-series data metrics. Let's see how to install and configure it.

Prepare the installation

1. Create Prometheus system user / group

   sudo groupadd --system prometheus
   
   sudo useradd -s /sbin/nologin --system -g prometheus prometheus

2. Create configuration and data directories

   sudo mkdir /var/lib/prometheus
   
   for i in rules rules.d files_sd; do sudo mkdir -p /etc/prometheus/${i}; done

Installation

1. Install cURL, then download the latest version of Prometheus

   sudo apt-get update
   
   sudo apt-get -y install wget curl
   
   mkdir -p /tmp/prometheus && cd /tmp/prometheus
   
   curl -s https://api.github.com/repos/prometheus/prometheus/releases/latest | grep browser_download_url | grep linux-amd64 | cut -d '"' -f 4 | wget -qi -

2. Extract the file

   tar xvf prometheus*.tar.gz
   
   cd prometheus*/

3. Finish the installation

   sudo mv prometheus promtool /usr/local/bin/
   
   sudo mv prometheus.yml /etc/prometheus/prometheus.yml
   
   sudo mv consoles/ console_libraries/ /etc/prometheus/
   
   cd ~/
   
   rm -rf /tmp/prometheus

Configuration

1. The configuration file can be found in the path below. Edit it to suit your needs

   nano /etc/prometheus/prometheus.yml

2. To be able to manage the Prometheus service with systemd, you need to explicitly define this unit file (it's a single command!)

   sudo tee /etc/systemd/system/prometheus.service<<EOF
   [Unit]
   Description=Prometheus
   Documentation=https://prometheus.io/docs/introduction/overview/
   Wants=network-online.target
   After=network-online.target
   
   [Service]
   Type=simple
   User=prometheus
   Group=prometheus
   ExecReload=/bin/kill -HUP $MAINPID
   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 \
     --web.listen-address=0.0.0.0:9090 \
     --web.external-url=
   
   SyslogIdentifier=prometheus
   Restart=always
   
   [Install]
   WantedBy=multi-user.target
   EOF

3. Edit permissions

   for i in rules rules.d files_sd; do sudo chown -R prometheus:prometheus /etc/prometheus/${i}; done
   
   for i in rules rules.d files_sd; do sudo chmod -R 775 /etc/prometheus/${i}; done
   
   sudo chown -R prometheus:prometheus /var/lib/prometheus/

4. Reload, enable and start the Prometheus service in systemd

   sudo systemctl daemon-reload
   
   sudo systemctl start prometheus
   
   sudo systemctl enable prometheus

5. Confirm that the service is up and running

   systemctl status prometheus

6. Access Prometheus web interface on URL http://[ip_hostname]:9090

   

7. That's all. If you have any comments/questions, leave them below.