Implement bootloader-universe script

This script downloads the grub and shim files and places them in the
correct locations.

It has various TODOs and is incomplete, but helps with providing the
structure. Long term this is better to be included in the TFTP module
itself and exposed via a REST API call.

It accepts a repo URL so it can be easily downloaded from Pulp
repositories.

Author: ekohl

extra/bootloader-universe

@@ -0,0 +1,68 @@
+#!/bin/bash
+
+set -xe
+
+# TODO: read from Smart Proxy config?
+TFTPROOT=/var/lib/tftpboot
+TFTPROOT=$PWD/tftpboot
+
+os=$1
+version=$2
+arch=$3
+repo=$4
+
+case $arch in
+	x86_64)
+		grub_arch=x64
+	# TODO
+esac
+
+grub="grub2-efi-${grub_arch}"
+shim="shim-${grub_arch}"
+
+if [[ -z $repo ]] ; then
+	major=${version%.*}
+	case $os in
+		almalinux)
+			repo=https://repo.almalinux.org/almalinux/${major}/BaseOS/${arch}/os
+			;;
+		centos)
+			repo=https://mirror.stream.centos.org/${major}-stream/BaseOS/${arch}/os
+			;;
+		redhat)
+			echo "Download from https://access.redhat.com/downloads/content/package-browser" 2>&1
+			exit 1
+			;;
+		rocky_linux)
+			repo=https://dl.rockylinux.org/pub/rocky/${major}/BaseOS/${arch}/os
+			;;
+		*)
+			echo "Unknown OS '${os}'" 2>&1
+			exit 1
+	esac
+fi
+
+BOOTLOADER_PATH="${TFTPROOT}/bootloader-universe/pxegrub2/${os}/${version}/${arch}"
+
+dir=$(mktemp -d)
+trap 'rm -rf "$dir"' EXIT
+
+(
+	cd "$dir"
+
+	dnf --repofrompath "temp-repo,$repo" download --arch "$arch" --from-repo temp-repo "$grub" "$shim"
+
+	rpm2cpio "$grub"* | cpio --extract --make-directories --verbose
+	rpm2cpio "$shim"* | cpio --extract --make-directories --verbose
+
+	if [[ $UID == 0 ]] ; then
+		install -o foreman-proxy -g foreman-proxy -d "${BOOTLOADER_PATH}"
+	else
+		install -d "${BOOTLOADER_PATH}"
+	fi
+	cp "boot/efi/EFI/${os}/grub${grub_arch}.efi" "${BOOTLOADER_PATH}/grub${grub_arch}.efi"
+	cp "boot/efi/EFI/${os}/shim${grub_arch}.efi" "${BOOTLOADER_PATH}/shim${grub_arch}.efi"
+	ln -sr "${BOOTLOADER_PATH}/grub${grub_arch}.efi" "${BOOTLOADER_PATH}/boot.efi"
+	ln -sr "${BOOTLOADER_PATH}/shim${grub_arch}.efi" "${BOOTLOADER_PATH}/boot-sb.efi"
+	chmod 0644 "${BOOTLOADER_PATH}/grub${grub_arch}.efi" "${BOOTLOADER_PATH}/shim${grub_arch}.efi"
+)