File 02_ignition_firstboot of Package ignition-dracut

#!/bin/sh
exec tail -n +3 $0
# On read-only systems /boot/writable provides a writeable
# subvolume which also stores the Ignition flag file.
set flagpath="/boot/writable"

# Determine if this is a first boot and set the variable
# to be used later on the kernel command line.
set ignition_firstboot=""
if [ -f "${flagpath}/ignition.firstboot" ]; then
    # default to dhcp networking parameters to be used with ignition 
    set ignition_network_kcmdline='rd.neednet=1 ip=dhcp'

    # source in the `ignition.firstboot` file which could override the
    # above $ignition_network_kcmdline with static networking config.
    # This override feature is primarily used by coreos-installer to
    # persist static networking config provided during install to the    
    # first boot of the machine.
    source "${flagpath}/ignition.firstboot"
    
    set ignition_firstboot="ignition.firstboot $ignition_network_kcmdline"
fi