Ansible Role: Prometheus

This Ansible role installs and configures Prometheus from the official GitHub release.
It also supports provisioning targets for Node Exporter.

The role performs the following tasks:

• Checks whether Prometheus is already installed
• Installs Prometheus if it is not present
• Creates a dedicated prometheus system user
• Creates required directories
• Downloads and installs Prometheus binaries
• Deploys Prometheus configuration
• Creates and enables a systemd service
• Optionally provisions Node Exporter targets

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Requirements

• Ansible >= 2.9
• Linux system with systemd
• Internet access to download Prometheus releases

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Role Variables

Variables are defined in defaults/main.yml.

Variable	Default	Description
prometheus_version	3.9.1	Prometheus version to install
provision	node_exporter	Enables Node Exporter provisioning

Example override:

prometheus_version: 3.9.1
provision: node_exporter

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Role Structure

ansible-role-prometheus
├── defaults
│   └── main.yml
├── files
│   └── config.yml
├── handlers
│   └── main.yml
├── meta
│   └── main.yml
├── tasks
│   ├── install.yml
│   ├── main.yml
│   └── provision_node_exporter.yml
├── templates
│   ├── node_exporter_targets.json.j2
│   ├── prometheus.service.j2
│   └── prometheus.yml.j2
├── tests
│   ├── ansible.cfg
│   ├── inventory.yml
│   └── test.yml
├── vars
│   └── main.yml
└── README.md

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What the Role Does

1. Checks whether Prometheus is installed:

which prometheus

2. If Prometheus is not installed:

• Creates the prometheus user
• Creates required directories:

/etc/prometheus
/var/lib/prometheus

3. Downloads Prometheus from GitHub releases.

4. Extracts the archive and installs binaries:

/usr/local/bin/prometheus
/usr/local/bin/promtool

5. Deploys the Prometheus configuration file:

/etc/prometheus/prometheus.yml

6. Installs the systemd service:

/etc/systemd/system/prometheus.service

7. Enables and starts Prometheus.

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Example Playbook

- hosts: prometheus
  become: true

  roles:
    - prometheus

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Example Inventory

all:
  hosts:
    prometheus:
      ansible_host: 192.168.1.10

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Prometheus Web Interface

After installation, Prometheus will be available at:

http://<server_ip>:9090

Check service status:

systemctl status prometheus

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Node Exporter Provisioning

This role supports automatic provisioning of Node Exporter targets using file-based service discovery.

Targets are generated from the template:

templates/node_exporter_targets.json.j2

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Testing

A simple test environment is available in the tests directory.

Run the test playbook:

ansible-playbook -i tests/inventory.yml tests/test.yml

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License

MIT