M #-: Polish script to RECREATE_RUN

src/etc/one-context.d/loc-04-run-dir

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 
 # -------------------------------------------------------------------------- #
-# Copyright 2002-2020, OpenNebula Project, OpenNebula Systems                #
+# Copyright 2002-2021, OpenNebula Project, OpenNebula Systems                #
 #                                                                            #
 # 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    #
@@ -16,37 +16,40 @@
 # limitations under the License.                                             #
 #--------------------------------------------------------------------------- #
 
-TMP_DIR=$(mktemp -d "/tmp/one-context.XXXXXX")
+set -e
 
 # Umount the directory and remove it
 cleanup()
 {
-    [ "$MOUNT" = "yes" ] && umount "${TMP_DIR}"
-    rm -rf "${TMP_DIR}"
+    [ "$MOUNTED" = "yes" ] && umount -l "${ROOTFS_DIR}"
+    rm -r "${TMP_DIR}"
 }
 
-# Get files that should be copy from
-get_files()
-{
-    diff -qr "$1" "$2" | grep "Only in $1" | cut -d ':' -f2 | awk '{$1=$1};1'
-}
-
-if [ "${RECREATE_TMPFS^^}" = "YES" ]; then
-    MOUNT=yes
-
-    mount --bind -o ro / "${TMP_DIR}"
-
-    IFS=$'\n'
-
-    # Copy only files that are in /run but not in /var/run
-    files=$(get_files "${TMP_DIR}"/run /var/run)
-
-    for file in $files;
-    do
-        cp -pr "${TMP_DIR}"/run/"${file}" /var/run &> /dev/null
-    done
+if [ "${RECREATE_RUN^^}" = "YES" ] && [ "$(uname -s)" = 'Linux' ]; then
+    # Detection of real run-time variable data directory in case there
+    # would be images with (unusual) reverse symlink /run -> /var/run
+    if [ -d /run ] && ! [ -L /run ]; then
+       RUN_DIR=/run
+    elif [ -d /var/run ] && ! [ -L /var/run ]; then
+       RUN_DIR=/var/run
+    else
+       # this shouldn't happen
+       echo 'ERROR: No suitable run-time data directory in image!' >&2
+       exit 1
+    fi
+
+    ###
+
+    TMP_DIR=$(mktemp -d "/tmp/one-context.XXXXXX")
+    ROOTFS_DIR="${TMP_DIR}/rootfs"
+    trap cleanup EXIT
+    chmod 0700 "${TMP_DIR}"
+    mkdir "${ROOTFS_DIR}"
+
+    mount --bind -o ro,nodev,noexec,nosuid / "${ROOTFS_DIR}"
+    MOUNTED=yes
+
+    # copy, but don't overwrite
+    # NOTE: using -i </dev/null is a workaround for silly cp in busybox without -n support
+    cp -aiv "${ROOTFS_DIR}/${RUN_DIR}" "$(dirname "${RUN_DIR}")" 2>/dev/null </dev/null
 fi
-
-trap cleanup EXIT
-
-exit 0