node-exporter-ansible-ops

Ansible role to install, upgrade, and manage Prometheus Node Exporter with systemd, backups, dry-run support, and safe rollback.

This role is designed for SREs, DevOps engineers, and monitoring teams who want a production-ready Node Exporter deployment that’s automated, versioned, and safe.

---

Features

• Install or update Node Exporter on Linux hosts
• Architecture-aware (amd64, arm64, armv7, ppc64le)
• Systemd integration with custom unit file
• Automatic backup of existing binary and unit file before upgrades
• Safe rollback if an update fails
• Dry-run mode to preview actions without making changes
• Configurable installation paths, users, and flags
• Easy to use in a role-based structure
• Bonus: Standalone Bash script for non-Ansible environments

---

Requirements

• Ansible ≥ 2.9
• Linux hosts (tested on Ubuntu, CentOS, Debian)
• Network access to the Node Exporter download URL
• tar and curl/wget installed on target hosts

---

Role Variables

Variable	Default	Description
running_action	"install"	Action to perform: install or update
dry_run	false	Set to true to preview changes without applying
node_exporter_version	"1.8.2"	Node Exporter version to install/update
ansible_architecture_map	{ x86_64: amd64, aarch64: arm64, armv7l: armv7, ppc64le: ppc64le }	Architecture mapping
node_exporter_arch	Calculated from ansible_architecture_map	System architecture for download
node_exporter_download_base_url	https://github.com/prometheus/node_exporter/releases/download/v{{ node_exporter_version }}	Base URL for Node Exporter releases
node_exporter_filename	"node_exporter-{{ node_exporter_version }}.linux-{{ node_exporter_arch }}"	Archive filename
node_exporter_tgz	"{{ node_exporter_filename }}.tar.gz"	Archive name
node_exporter_url	"{{ node_exporter_download_base_url }}/{{ node_exporter_tgz }}"	Download URL
node_exporter_install_dir	"/opt/node_exporter"	Directory to store backups
node_exporter_binary_dir	"/usr/local/bin"	Directory for the binary
node_exporter_binary_path	"{{ node_exporter_binary_dir }}/node_exporter"	Full path to binary
node_exporter_service_name	"node_exporter"	Systemd service name
node_exporter_user	"node_exporter"	User to run the service
node_exporter_group	"node_exporter"	Group for the service
node_exporter_flags	"--collector.systemd --collector.textfile.directory=/var/log/value_monitor"	Node Exporter flags
node_exporter_backup_dir	"{{ node_exporter_install_dir }}/backups"	Backup directory
backup_ts	"{{ ansible_date_time.epoch }}"	Timestamp for backups
backup_binary_path	"{{ node_exporter_backup_dir }}/node_exporter-{{ backup_ts }}"	Backup path for binary
backup_unit_path	"{{ node_exporter_backup_dir }}/{{ node_exporter_service_name }}.service-{{ backup_ts }}"	Backup path for systemd unit

⚠️ All variables can be overridden in your playbook or inventory.

---

Example Inventory

[monitoring_nodes]
server1 ansible_host=192.168.1.100 ansible_port=22 ansible_user=root
server2 ansible_host=192.168.1.101 ansible_port=22 ansible_user=root

---

Example Playbook

- name: Node Exporter ops
  hosts: "{{ HOSTS }}"
  become: true
  gather_facts: true

  roles:
    - role: node_exporter
      vars:
        running_action: "update"
        NODE_EXPORTER_VERSION: "1.9.1"
        DRY_RUN: false

---

Dry-Run Mode

Preview what would happen without making any changes:

ansible-playbook -i inventory.ini playbook.yml \
  -e "HOSTS=monitoring_nodes ACTION=install NODE_EXPORTER_VERSION=1.8.2 DRY_RUN=true"

This will show steps like:

• Whether Node Exporter will be installed or updated
• Whether the service will be stopped
• Where backups will be created

---

Usage Examples

Install Node Exporter

ansible-playbook -i inventory.ini playbook.yml \
  -e "HOSTS=monitoring_nodes ACTION=install NODE_EXPORTER_VERSION=1.8.2"

Update Node Exporter

ansible-playbook -i inventory.ini playbook.yml \
  -e "HOSTS=monitoring_nodes ACTION=update NODE_EXPORTER_VERSION=1.9.0"

With Dry Run

ansible-playbook -i inventory.ini playbook.yml \
  -e "HOSTS=monitoring_nodes ACTION=update NODE_EXPORTER_VERSION=1.9.0 DRY_RUN=true"

---

Backup & Rollback

• Before updating, the existing binary and systemd unit file are backed up automatically.
• In case of failure, the role will attempt to rollback to the last working version.
• Backup files are stored under:

/opt/node_exporter/backups/

---

Systemd Service

The service file is deployed from a Jinja2 template and includes:

• Automatic restart on failure
• Customizable user/group
• Network target dependency
• Node Exporter flags configurable via node_exporter_flags

---

🖥️ Standalone Bash Installer

For environments without Ansible, a Bash script (node_exporter_ops.sh) is included. It provides the same features (install, update, dry-run, rollback).

Usage

./node_exporter_ops.sh --action install --version 1.9.1 --dry-run false \
  --flags "--collector.systemd --collector.textfile.directory=/var/log/value_monitor"

Options

--action install|update     Action to perform (required)
--version X.Y.Z             Node Exporter version (required)
--dry-run true|false        Preview actions without applying
--flags "..."                Extra runtime flags for Node Exporter
--install-dir DIR           Install directory (default: /opt/node_exporter)
--binary-dir DIR            Binary directory (default: /usr/local/bin)
--user USER                 System user (default: node_exporter)
--group GROUP               System group (default: node_exporter)
--service-name NAME         Systemd service name (default: node_exporter)
--backup-dir DIR            Directory for backups (default: /opt/node_exporter/backups)

Examples

Install Node Exporter v1.8.2:

sudo ./node_exporter_ops.sh --action install --version 1.8.2

Update Node Exporter to v1.9.1 with custom flags:

sudo ./node_exporter_ops.sh --action update --version 1.9.1 \
  --flags "--collector.systemd --collector.cpu"

Dry-run preview:

sudo ./node_exporter_ops.sh --action install --version 1.9.1 --dry-run true

Rollback (automatic):

• If an update fails, the script restores the last binary and systemd unit from the backup folder.

---

Contributing

• Open an issue or pull request for bugs or feature requests.
• Follow standard Ansible style (snake_case, idempotency, modular tasks).

---

License

This project is licensed under the MIT License – see the LICENSE file.