Update download_debian.sh script for Debian 13 (trixie)

cf @bug4451 https://bugzilla.ipr.univ-rennes.fr/show_bug.cgi?id=4451

scripts/download_debian.sh

@@ -1,11 +1,14 @@
 #!/bin/bash
 
 # Purpose {{{
-# This script will download Debian netboot installer for both AMD64 and i368
+# This script will download Debian netboot installer and make a sample
-#   1. Debian oldStable (Bookworm)
+# menu.cfg config file.
-#   2. Debian oldStable (Bullseye)
+#   1. Debian Stable (Trixie)      − amd64
-#   3. Debian Unstable (Sid)
+#   2. Debian oldStable (Bookworm) − amd64, i386
-# and make a sample menu.cfg config file.
+#   3. Debian Unstable (Sid)       − amd64
+#
+# Note: i386 is no longer provided as an installation architecture from
+# Trixie onwards, so the architecture list is per-suite.
 # }}}
 # Vars {{{
 readonly PROGNAME=$(basename "${0}")
@@ -26,6 +29,9 @@ DEBIAN_INSTALLER_DIR="${TFTP_DIRECTORY}/installer/debian"
 # tftp sample config file
 DEBIAN_CONFIG_PXE="${DEBIAN_INSTALLER_DIR}/menu.cfg.example"
 
+# Debian suites to fetch
+DEBIAN_SUITES="trixie bookworm sid"
+
 ## Colors
 readonly PURPLE='\033[1;35m'
 readonly RED='\033[0;31m'
@@ -38,13 +44,16 @@ usage() {                                                       # {{{
 usage: $PROGNAME [-d|-h]
 
 This script will download "all" Debian's netboot installer for
-tftp server for both AMD64 and i368 architectures.
+tftp server.
 
-EXAMPLES :
+Architectures are selected per suite: i386 is no longer provided
+as an installation architecture from Trixie onwards.
+
+EXAMPLES :
     - Download Debian's installers to default place (${TFTP_DIRECTORY})
         ${PROGNAME}
 
-OPTIONS :
+OPTIONS :
     -d,--debug
         Enable debug messages.
 
@@ -60,7 +69,7 @@ debug_message() {                                               # {{{
 	local_message="${1}"
 
 	## Print message if DEBUG is enable (=0)
-	[ "${DEBUG}" -eq "0" ] && printf '\e[1;35m%-6b\e[m\n' "DEBUG − ${PROGNAME} : ${local_message}"
+	[ "${DEBUG}" -eq "0" ] && printf '\e[1;35m%-6b\e[m\n' "DEBUG − ${PROGNAME} : ${local_message}"
 
 	return 0
 }
@@ -71,13 +80,40 @@ error_message() {                                               # {{{
 	local_error_code="${2}"
 
 	## Print message
-	printf '%b\n' "ERROR − ${PROGNAME} : ${RED}${local_error_message}${RESET}"
+	printf '%b\n' "ERROR − ${PROGNAME} : ${RED}${local_error_message}${RESET}"
 
 	exit "${local_error_code:=66}"
 }
 # }}}
 
+get_arch_list() {                                               # {{{
+# Return the list of architectures available for a given Debian suite.
+# i386 was dropped as an installation architecture starting with Trixie.
+
+	local_distro="${1}"
+
+	case "${local_distro}" in
+		trixie|sid|forky )
+			return_arch_list="amd64"
+			;;
+		* )
+			return_arch_list="amd64 i386"
+			;;
+	esac
+
+	debug_message "get_arch_list − \
+Architectures for ${RED}${local_distro}${COLOR_DEBUG} : ${RED}${return_arch_list}${COLOR_DEBUG} ."
+
+	## Unset variables
+	unset local_distro
+
+	printf '%s' "${return_arch_list}"
+}
+# }}}
 download_file() {                                               # {{{
+# Download a file to a temporary location and move it into place only if
+# the transfer succeeded. A failed download therefore never overwrites a
+# working file with an empty one.
 
 	local_url="${1}"
 	local_dest_file="${2}"
@@ -85,11 +121,24 @@ download_file() {                                               # {{{
 	debug_message "download_file − \
 Download ${local_url} to ${RED}${local_dest_file}${COLOR_DEBUG} ."
 
-	wget --quiet "${local_url}" --output-document="${local_dest_file}"
+	local_tmp_file="${local_dest_file}.part"
+
+	if wget --quiet "${local_url}" --output-document="${local_tmp_file}"; then
+		mv -- "${local_tmp_file}" "${local_dest_file}"
+		return_download_file="0"
+	else
+		rm --force -- "${local_tmp_file}"
+		debug_message "download_file − \
+Download of ${RED}${local_url}${COLOR_DEBUG} failed."
+		return_download_file="1"
+	fi
 
 	## Unset variables
 	unset local_url
 	unset local_dest_file
+	unset local_tmp_file
+
+	return "${return_download_file}"
 }
 # }}}
 is_file_empty() {                                               # {{{
@@ -129,27 +178,33 @@ Create ${DEBIAN_INSTALLER_DIR} tree."
 	true > "${DEBIAN_CONFIG_PXE}"
 
 	# Parse all Debian's distribution
-	for DISTRO in bookworm bullseye sid; do # For "all" Debian's version
+	for DISTRO in ${DEBIAN_SUITES}; do          # For "all" Debian's version
+
+		## Architecture list depends on the suite
+		ARCH_LIST=$(get_arch_list "${DISTRO}")
+
 		## Then parse architecture
-		for ARCH in amd64 i386; do                  # For all classic architecture
+		for ARCH in ${ARCH_LIST}; do
 		debug_message "Main FOR loop − \
 Manage ${RED}${DISTRO}${COLOR_DEBUG} release with ${RED}${ARCH}${COLOR_DEBUG} architecture."
 
 			### Create destination directory
-			mkdir --parents -- ${DEBIAN_INSTALLER_DIR}/${DISTRO}/${ARCH} \
+			mkdir --parents -- "${DEBIAN_INSTALLER_DIR}/${DISTRO}/${ARCH}" \
 				|| error_message "Can't create ${DEBIAN_INSTALLER_DIR}/${DISTRO}/${ARCH} tree." "1"
 
 			### Download linux file
 			download_file "http://deb.debian.org/debian/dists/${DISTRO}/main/installer-${ARCH}/current/images/netboot/debian-installer/${ARCH}/linux" \
-				"${DEBIAN_INSTALLER_DIR}/${DISTRO}/${ARCH}/linux"
+				"${DEBIAN_INSTALLER_DIR}/${DISTRO}/${ARCH}/linux" \
+				|| error_message "Can't download linux for ${DISTRO}/${ARCH} !" "2"
 			is_file_empty "${DEBIAN_INSTALLER_DIR}/${DISTRO}/${ARCH}/linux" \
-				&& error_message "${DEBIAN_INSTALLER_DIR}/${DISTRO}/${ARCH}/linux is empty !" "2"
+				&& error_message "${DEBIAN_INSTALLER_DIR}/${DISTRO}/${ARCH}/linux is empty !" "2"
 
 			### Download initrd.gz
 			download_file "http://deb.debian.org/debian/dists/${DISTRO}/main/installer-${ARCH}/current/images/netboot/debian-installer/${ARCH}/initrd.gz" \
-				"${DEBIAN_INSTALLER_DIR}/${DISTRO}/${ARCH}/initrd.gz"
+				"${DEBIAN_INSTALLER_DIR}/${DISTRO}/${ARCH}/initrd.gz" \
+				|| error_message "Can't download initrd.gz for ${DISTRO}/${ARCH} !" "2"
 			is_file_empty "${DEBIAN_INSTALLER_DIR}/${DISTRO}/${ARCH}/initrd.gz" \
-				&& error_message "${DEBIAN_INSTALLER_DIR}/${DISTRO}/${ARCH}/initrd.gz is empty !" "2"
+				&& error_message "${DEBIAN_INSTALLER_DIR}/${DISTRO}/${ARCH}/initrd.gz is empty !" "2"
 
 			### Config file
 			debug_message "Main FOR loop − \