zbm-builder.sh: add script to build custom images using GHCR container

zbm-builder.sh

@@ -0,0 +1,102 @@
+#!/bin/bash
+# vim: softtabstop=2 shiftwidth=2 expandtab
+
+usage() {
+  cat <<EOF
+Usage: $0 [options]
+  OPTIONS:
+  -h Display help text
+
+  -H Do not copy /etc/hostid into image
+     (Has no effect if ./hostid exists)
+
+  -C Do not copy /etc/zfs/zpool.cache into image
+     (Has no effect if ./zpool.cache exists)
+
+  -d Force use of docker instead of podman
+
+  -t <tag>
+     Build the given ZFSBootMenu tag
+     (Default: upstream master)
+
+  -B <tag>
+     Use the given zbm-builder tag to build images
+     (Default: ghcr.io/zbm-dev/zbm-builder:latest)
+EOF
+}
+
+if command -v podman >/dev/null 2>&1; then
+  PODMAN=podman
+elif command -v docker >/dev/null 2>&1; then
+  PODMAN=docker
+fi
+
+SKIP_HOSTID=
+SKIP_CACHE=
+
+BUILD_TAG="ghcr.io/zbm-dev/zbm-builder:latest"
+
+BUILD_ARGS=()
+
+while getopts "hHCdt:B:" opt; do
+  case "${opt}" in
+    H)
+      SKIP_HOSTID="yes"
+      ;;
+    C)
+      SKIP_CACHE="yes"
+      ;;
+    d)
+      PODMAN=docker
+      ;;
+    t)
+      BUILD_ARGS+=( "-t" "${OPTARG}" )
+      ;;
+    B)
+      BUILD_TAG="${OPTARG}"
+      ;;
+    h)
+      usage
+      exit 0
+      ;;
+    *)
+      usage
+      exit 1
+      ;;
+  esac
+done
+
+if ! command -v "${PODMAN}" >/dev/null 2>&1; then
+  echo "ERROR: container front-end ${PODMAN} not found"
+  exit 1
+fi
+
+# If no local hostid is available, copy the system hostid if desired
+if ! [ -r ./hostid ]; then
+  if [ "${SKIP_HOSTID}" != "yes" ] && [ -r /etc/hostid ]; then
+    if ! cp /etc/hostid ./hostid; then
+      echo "ERROR: unable to copy /etc/hostid"
+      echo "Copy a hostid file to ./hostid or use -H to disable"
+      exit 1
+    fi
+  fi
+fi
+
+# If no local zpool.cache is available, copy the system cache if desired
+if ! [ -r ./zpool.cache ]; then
+  if [ "${SKIP_CACHE}" != "yes" ] && [ -r /etc/zfs/zpool.cache ]; then
+    if ! cp /etc/zfs/zpool.cache ./zpool.cache; then
+      echo "ERROR: unable to copy /etc/zfs/zpool.cache"
+      echo "Copy a zpool cache to ./zpool.cache or use -C to disable"
+      exit 1
+    fi
+  fi
+fi
+
+# If no config is specified, use in-tree default
+if ! [ -r ./config.yaml ]; then
+  BUILD_ARGS+=( "-c" "/zbm/etc/zfsbootomenu/config.yaml" )
+fi
+
+# Make `/build` the working directory so relative paths in a config file make sense
+"${PODMAN}" run --rm -v ".:/build" -w "/build" "${BUILD_TAG}" "${BUILD_ARGS[@]}"