releng/docker/image-build.sh: support custom XBPS repositories

- Allow mounting of one or more host directories into buildah container
  to use as custom repositories when creating the build image

- Allow specification of one or more custom remote repositories that
  will take precedence over the XBPS default repository

- Fixup: prune headers for all default-installed kernels

releng/docker/image-build.sh

@@ -1,13 +1,23 @@
-#!/bin/sh
+#!/bin/bash
 # vim: softtabstop=2 shiftwidth=2 expandtab
 
 usage() {
   cat <<-EOF
-	USAGE: $0 [-h] [-p <pkg>] <tag> [zbm-commit-like]
+	USAGE: $0 [-h] [-r <path>] [-R <repo>] [-p <pkg>] <tag> [zbm-commit-like]
 	Create a container image for building ZFSBootMenu
 	
 	-h: Display this message and exit
 	
+	-r <path>:
+	   Mount the specified path into the build container when installing
+	   packages and configure XBPS to use the path as a package repository
+	
+	   (One path per argument; may be repeated as needed)
+	
+	-R <repo>:
+	   Configure XBPS to use the specified Void Linux package repository
+	   (One repository per argument; may be repeated as needed)
+	
 	-p <pkg>:
 	   Include the specified Void Linux package in the image
 	   (One package per argument; may be repeated as needed)
@@ -23,11 +33,35 @@ usage() {
 
 set -o errexit
 
-extra_pkgs=""
-while getopts "hp:" opt; do
+extra_pkgs=()
+
+host_mounts=()
+host_repos=()
+
+web_repos=()
+
+while getopts "hp:r:R:" opt; do
   case "${opt}" in
     p)
-      extra_pkgs="${extra_pkgs} ${OPTARG}"
+      extra_pkgs+=( "${OPTARG}" )
+      ;;
+    r)
+      target="/pkgs/${#host_repos[@]}"
+      host_repos+=( "${target}" )
+      host_mounts+=( --mount "type=bind,src=${OPTARG},dst=${target},ro" )
+      ;;
+    R)
+      # Sanitize repo arguments
+      case "${OPTARG}" in
+        /*|http://*|https://*)
+          ;;
+        *)
+          echo "ERROR: '${OPTARG}' does not appear to be a valid repository"
+          exit 1
+          ;;
+      esac
+
+      web_repos+=( "${OPTARG}" )
       ;;
     h)
       usage
@@ -72,20 +106,22 @@ container="$(buildah from ghcr.io/void-linux/void-linux:latest-full-x86_64)"
 
 buildah config --label author="${maintainer}" "${container}"
 
-# Use servercentral.com by default
-buildah run "${container}" sh -c "cat > /etc/xbps.d/00-repository-main.conf" <<-EOF
-	repository=https://mirrors.servercentral.com/voidlinux/current
-EOF
+# Favor custom repositories
+for repo in "${host_repos[@]}" "${web_repos[@]}"; do
+  buildah run "${container}" sh -c "cat >> /etc/xbps.d/00-custom-repos.conf" <<-EOF
+	repository=${repo}
+	EOF
+done
 
 # Make sure image is up to date
-buildah run "${container}" xbps-install -Syu xbps
-buildah run "${container}" xbps-install -Syu
+buildah run "${host_mounts[@]}" "${container}" xbps-install -Syu xbps
+buildah run "${host_mounts[@]}" "${container}" xbps-install -Syu
 
 # Add extra packages, as desired
-if [ -n "${extra_pkgs}" ]; then
-  echo "INFO: adding extra Void packages: ${extra_pkgs}"
+if [ "${#extra_pkgs[@]}" -gt 0 ]; then
+  echo "INFO: adding extra Void packages: ${extra_pkgs[*]}"
   # shellcheck disable=SC2086
-  buildah run "${container}" xbps-install -y ${extra_pkgs}
+  buildah run "${host_mounts[@]}" "${container}" xbps-install -y "${extra_pkgs[@]}"
 fi
 
 # Prefer an LTS version over whatever Void thinks is current
@@ -101,9 +137,10 @@ buildah run "${container}" sh -c "cat > /etc/xbps.d/15-noinitramfs.conf" <<-EOF
 EOF
 
 # Install ZFSBootMenu dependencies and components necessary to build images
-buildah run "${container}" \
+buildah run "${host_mounts[@]}" "${container}" \
   sh -c 'xbps-query -Rp run_depends zfsbootmenu | xargs xbps-install -y'
-buildah run "${container}" xbps-install -y linux5.10 linux5.10-headers \
+buildah run "${host_mounts[@]}" "${container}" \
+  xbps-install -y linux5.10 linux5.10-headers \
   linux5.15 linux5.15-headers linux6.1 linux6.1-headers zstd \
   gummiboot-efistub curl yq-go bash kbd terminus-font \
   dracut mkinitcpio dracut-network gptfdisk iproute2 iputils parted curl \
@@ -112,7 +149,8 @@ buildah run "${container}" xbps-install -y linux5.10 linux5.10-headers \
 # Remove headers and development toolchain, but keep binutils for objcopy
 buildah run "${container}" sh -c 'echo "ignorepkg=dkms" > /etc/xbps.d/10-nodkms.conf'
 buildah run "${container}" xbps-pkgdb -m manual binutils
-buildah run "${container}" xbps-remove -Roy linux5.10-headers dkms
+buildah run "${container}" \
+  xbps-remove -Roy linux5.10-headers linux5.15-headers linux6.1-headers dkms
 buildah run "${container}" sh -c 'rm -f /var/cache/xbps/*'
 
 # Record a commit hash if one is available