Ansible Role: NHC (Node Health Check)

This role installs and configures the NHC (Node Health Check) software, which is a tool for monitoring and checking the health of compute nodes in a cluster environment.

Description

This role provides a way to:

• Install NHC package
• Configure NHC through its configuration file
• Set up NHC environment variables
• Support package upgrades when needed

Requirements

• Ansible 2.16 or higher
• Target systems must be running a supported Linux distribution (Debian/Ubuntu)

Role Variables

Available variables are listed below. See defaults/main.yml for default values.

# Package name to install
nhc_packages: nhc

# Whether to upgrade the package (true/false)
nhc_upgrade: false

# NHC configuration content
# Example:
# nhc_config: |
#   * || check_fs_mount_rw /
#   * || check_hw_cpuinfo 2 8 8
#   * || check_hw_physmem 1k 1TB

# List of NHC environment variables
# See https://github.com/mej/nhc?tab=readme-ov-file#supported-variables
# Example:
# nhc_variables:
#   - NHC_RM=slurm
#   - HELPERDIR=/opt/nhc/libexec/nhc/

# List of NHC custom scripts
# `src` is mandatory
# `dest` and `state` are optional
nhc_scripts:
  # Add a custom script
  - src: "{{ inventory_dir }}/files/nhc/custom_script.nhc"
  # Add a script to custom INCDIR
  - src: "{{ inventory_dir }}/files/nhc/custom_script_foo.nhc"
    dest: '/opt/nhc/scripts/custom_script_foo.nhc'
  # Remove a script
  - src: "{{ inventory_dir }}/files/nhc/custom_script_bar.nhc"
    state: absent

Example Playbook

Install and configure NHC:

- hosts: computes
  roles:
    - role: btravouillon.nhc
      tags: role::nhc
      vars:
        nhc_config: |
          # Check that / is mounted read-write.
          * || check_fs_mount_rw /
          # Check that there are 2 physical CPUs, 8 actual cores, and 8 threads
          * || check_hw_cpuinfo 2 8 8
          # Check that we have between 1kB and 1TB of physical RAM
          * || check_hw_physmem 1k 1TB
        nhc_variables:
          - NHC_RM=slurm
          - HELPERDIR=/opt/nhc/libexec/nhc/

License

See the LICENSE file for details.