Helper script for package installation in Micro images

ga/26.0.0.9/kernel/helpers/build/install-packages.sh

@@ -0,0 +1,240 @@
+#!/bin/bash
+# (C) Copyright IBM Corporation 2026.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Used in multi-stage Dockerfiles: --install collects package files + .so deps
+# into /tmp/pkg-files (builder); --copy copies missing files into the micro image.
+
+if [ "${VERBOSE}" != "true" ]; then
+  exec >/dev/null 2>&1
+fi
+
+set -Eeo pipefail
+
+PKG_DIR="${PKG_DIR:-/tmp/pkg-files}"
+
+usage() {
+  echo "Usage: $0 --install <pkg> [<pkg> ...]  |  --copy [<from-dir>]" >&2
+  exit 1
+}
+
+[ "$#" -eq 0 ] && usage
+
+MODE="$1"; shift
+
+# Normalise compat symlink prefixes so all paths land under /usr.
+normalise_path() {
+  local p="$1"
+  p="${p/#\/lib64\//\/usr\/lib64\/}"
+  p="${p/#\/lib\//\/usr\/lib\/}"
+  p="${p/#\/bin\//\/usr\/bin\/}"
+  p="${p/#\/sbin\//\/usr\/sbin\/}"
+  printf '%s' "$p"
+}
+
+# Extract every resolved absolute library path from ldd output.
+collect_ldd_deps() {
+  ldd "$1" 2>/dev/null \
+    | awk '
+      /=>/ && $3 ~ /^\// { print $3; next }
+      $1 ~ /^\/[^ ]/ && !/=>/ { print $1 }
+    ' \
+    | grep -v '^$' || true
+}
+
+# Copy a file and every symlink hop in its chain into PKG_DIR.
+copy_to_pkg_dir() {
+  local pkg_dir="$1" current="$2"
+
+  [[ "$current" = /* ]] || { echo "WARNING: skipping non-absolute path: $current" >&2; return; }
+
+  local visited=()
+  while true; do
+    local v
+    for v in "${visited[@]}"; do
+      if [ "$v" = "$current" ]; then
+        echo "WARNING: symlink loop at $current, stopping" >&2
+        return
+      fi
+    done
+    visited+=("$current")
+
+    if [ ! -e "$current" ] && [ ! -L "$current" ]; then
+      echo "WARNING: path not found, skipping: $current" >&2
+      return
+    fi
+
+    mkdir -p "${pkg_dir}$(dirname "$current")"
+
+    if [ -L "$current" ]; then
+      local link_target dest_link
+      link_target="$(readlink "$current")"
+      dest_link="${pkg_dir}${current}"
+      if [ ! -e "$dest_link" ] && [ ! -L "$dest_link" ]; then
+        cp -P "$current" "$dest_link"
+        echo "  symlink  $current -> $link_target"
+      fi
+      if [[ "$link_target" = /* ]]; then
+        current="$link_target"
+      else
+        current="$(realpath -m "$(dirname "$current")/$link_target")"
+      fi
+    elif [ -f "$current" ]; then
+      local dest_file="${pkg_dir}${current}"
+      if [ ! -e "$dest_file" ]; then
+        cp -a "$current" "$dest_file"
+        echo "  file     $current"
+      fi
+      break
+    else
+      echo "WARNING: unexpected file type, skipping: $current" >&2
+      break
+    fi
+  done
+}
+
+cmd_install() {
+  [ "$#" -eq 0 ] && { echo "ERROR: --install requires at least one package name" >&2; exit 1; }
+  echo "-- install-packages --install $*"
+
+  local pkg_dir="${PKG_DIR}"
+  local pre_install post_install diff_pkgs all_pkgs pkg rpm_file
+
+  echo "Updating image"
+  microdnf -y update
+  microdnf clean all
+
+  # Remove individually so a missing package doesn't skip the rest; ensures
+  # packages already in the builder image appear in the pre/post diff.
+  for pkg in "$@"; do
+    microdnf -y remove "$pkg" || true
+  done
+
+  pre_install="$(rpm -qa --queryformat '%{NAME}\n' | sort)"
+
+  echo "Installing: $*"
+  microdnf -y install "$@"
+  microdnf clean all
+
+  post_install="$(rpm -qa --queryformat '%{NAME}\n' | sort)"
+  diff_pkgs="$(comm -13 <(echo "$pre_install") <(echo "$post_install") 2>&1)" || {
+    echo "WARNING: comm failed resolving package diff, auto-deps may be incomplete: ${diff_pkgs}" >&2
+    diff_pkgs=""
+  }
+
+  all_pkgs="$(printf '%s\n' "$@" "${diff_pkgs}" | sort -u)"
+  echo "Packages to collect: $(echo "$all_pkgs" | tr '\n' ' ')"
+
+  declare -A SEEN
+
+  for pkg in $all_pkgs; do
+    if ! rpm -q "$pkg" &>/dev/null; then
+      echo "WARNING: package not found in RPM db, skipping: $pkg" >&2
+      continue
+    fi
+    while IFS= read -r rpm_file; do
+      case "$rpm_file" in
+        /usr/bin/*|/usr/sbin/*|/usr/libexec/*)
+          [[ "$rpm_file" == "/usr/sbin/init" ]] && continue
+          [ -e "$rpm_file" ] && SEEN["$rpm_file"]=1 ;;
+        /usr/lib64/*.so*|/usr/lib/*.so*)
+          [ -e "$rpm_file" ] && SEEN["$rpm_file"]=1 ;;
+      esac
+    done < <(rpm -ql "$pkg" 2>/dev/null || true) || true
+  done
+
+  echo "Resolving transitive .so dependencies via ldd"
+  local changed=1 path lib keys
+  while [ "$changed" -eq 1 ]; do
+    changed=0
+    keys=("${!SEEN[@]}")
+    for path in "${keys[@]}"; do
+      [ -f "$path" ] || continue
+      [[ "$(head -c 4 "$path" 2>/dev/null)" == $'\x7fELF' ]] || continue
+      while IFS= read -r lib; do
+        lib="$(normalise_path "$lib")"
+        if [ -n "$lib" ] && [ -e "$lib" ] && [ -z "${SEEN[$lib]+x}" ]; then
+          SEEN["$lib"]=1
+          changed=1
+        fi
+      done < <(collect_ldd_deps "$path") || true
+    done
+  done
+
+  echo "Total paths to collect: ${#SEEN[@]}"
+  [[ "${#SEEN[@]}" -eq 0 ]] && echo "WARNING: nothing to collect — check package names and filters" >&2 || true
+
+  mkdir -p "${pkg_dir}"
+  for path in "${!SEEN[@]}"; do
+    copy_to_pkg_dir "$pkg_dir" "$path"
+  done
+
+  echo "Total files: $(find "${pkg_dir}" -type f | wc -l)"
+}
+
+cmd_copy() {
+  local from_dir="${1:-${PKG_DIR}}"
+
+  if [ ! -d "$from_dir" ]; then
+    echo "ERROR: source directory not found: $from_dir" >&2
+    exit 1
+  fi
+
+  echo "Copying missing files from ${from_dir} into /"
+
+  local copied=0 skipped=0 warned=0
+  while IFS= read -r src; do
+    local dest="${src#"${from_dir}"}"
+    [ -z "$dest" ] && continue
+
+    # Skip absolute-target symlinks whose target is absent from PKG_DIR.
+    if [ -L "$src" ]; then
+      local link_target
+      link_target="$(readlink "$src")"
+      if [[ "$link_target" = /* ]]; then
+        if [ ! -e "${from_dir}${link_target}" ] && [ ! -L "${from_dir}${link_target}" ]; then
+          echo "WARNING: symlink $dest -> $link_target has no target in PKG_DIR, skipping" >&2
+          (( warned++ )) || true
+          continue
+        fi
+      fi
+    fi
+
+    if [ ! -e "$dest" ] && [ ! -L "$dest" ]; then
+      mkdir -p "$(dirname "$dest")"
+      cp -a "$src" "$dest"
+      echo "  copied  $dest"
+      (( copied++ )) || true
+    else
+      (( skipped++ )) || true
+    fi
+  done < <(find "$from_dir" \( -type f -o -type l \) | sort)
+
+  echo "Done. Copied: ${copied}, skipped: ${skipped}, warned: ${warned}"
+
+  local dangling=0
+  while IFS= read -r link; do
+    echo "WARNING: dangling symlink in image: $link -> $(readlink "$link")" >&2
+    (( dangling++ )) || true
+  done < <(find / -xdev -type l ! -exec test -e {} \; -print 2>/dev/null || true)
+  [ "$dangling" -gt 0 ] && echo "WARNING: ${dangling} dangling symlink(s) found after copy" >&2 || true
+
+  rm -rf "${from_dir}"
+}
+
+case "$MODE" in
+  --install) cmd_install "$@" ;;
+  --copy)    cmd_copy    "$@" ;;
+  *)         usage ;;
+esac