AlpineLinux PXE boot specify startup script as kernel parameter

Question

Is there a way to specify a script as kernel parameter during pxe boot? I want run a bunch of computers as workers. I want them to use PXE to boot AlpineLinux and then run a bash script that will load my app and join my cluster.

Answer 1

Change dir:

cd /tmp

Create directory structure:

.
└── etc
    ├── init.d
    │   └── local.stop
    └── runlevels
        └── default
            └── local.stop -> /etc/init.d/local.stop

mkdir -p ./etc/{init.d,runlevels/default}/

Create file ./etc/init.d/local.stop:

#!/sbin/openrc-run

start () {
    wget http://172.16.11.8/rickroll/video.mp4 -O /root/video.mp4
}

chmod +x ./etc/init.d/local.stop

cd /tmp/etc/runlevels/default

Make symlink:

ln -s /etc/init.d/local.stop local.stop

Go back:

cd /tmp

Create archive:

tar -czvf alpine-test-01.tar.gz ./etc/

Make pxelinux (on your tftp server) menu:

label insatll-alpine
    menu label Install Alpine Linux [test]
    kernel alpine-installer/boot/vmlinuz-lts
    initrd alpine-installer/boot/initramfs-lts
    append ip=dhcp alpine_repo=https://dl-cdn.alpinelinux.org/alpine/latest-stable/main modloop=https://dl-cdn.alpinelinux.org/alpine/latest-stable/releases/x86_64/netboot/modloop-lts modules=loop,squashfs,sd-mod,usb-storage apkovl=http://{YOUR_WEBSERVER}/{YOUR_DIR}/alpine-test-01.tar.gz

And run:

My webserver log:

10.10.15.43 172.16.11.8 - [27/Aug/2021:01:15:22 +0300] "GET /rickroll/video.mp4 HTTP/1.1" 200 5853379 "-" "Wget"