nullr0ute / greenboot

Generic Health Checking Framework for systemd

greenboot

Generic Health Check Framework for systemd

Installation

On Fedora Silverblue, Fedora IoT or Fedora CoreOS:

rpm-ostree install greenboot greenboot-status greenboot-ostree-grub2

systemctl reboot

Usage

Place shell scripts representing health checks that MUST NOT FAIL in the /etc/greenboot/check/required.d directory. Place shell scripts representing health checks that MAY FAIL in the /etc/greenboot/check/wanted.d directory. Place shell scripts you want to run after a boot has been declared successful in /etc/greenboot/green.d. Place shell scripts you want to run after a boot has been declared failed in /etc/greenboot/red.d.

Unless greenboot is enabled by default in your distribution, enable it by running systemctl enable greenboot greenboot-healthcheck greenboot-status. It will automatically start during the next boot process and run its checks.

When you ssh into the machine after that, a boot status message will be shown.

Directory structure:

/etc
└── greenboot
    ├── check
    │   ├── required.d
    │   └── wanted.d
    ├── green.d
    └── red.d

Health Checks with systemd services

Overall boot success is measured against boot-complete.target. Ordering of units can be achieved using standard systemd vocabulary.

Required Checks

Create a oneshot health check service unit that MUST NOT FAIL, e.g. /etc/systemd/system/required-check.service. Run systemctl enable required-check to enable it.

[Unit]
Description=Custom Required Health Check
Before=boot-complete.target
OnFailure=redboot.target
OnFailureJobMode=fail

[Service]
Type=oneshot
ExecStart=/usr/libexec/mytestsuite/required-check

[Install]
RequiredBy=boot-complete.target
WantedBy=multi-user.target

Wanted Checks

Create a oneshot health check service unit that MAY FAIL, e.g. /etc/systemd/system/wanted-check.service. Run systemctl enable wanted-check to enable it.

[Unit]
Description=Custom Wanted Health Check
Before=boot-complete.target

[Service]
Type=oneshot
ExecStart=/usr/libexec/mytestsuite/wanted-check

[Install]
WantedBy=boot-complete.target
WantedBy=multi-user.target