From 048c1724bfc3dde09be46ff3d2a432583c49a9d1 Mon Sep 17 00:00:00 2001
From: "Gerd v. Egidy" <gerd@egidy.de>
Date: Mon, 10 Jan 2022 22:47:21 +0100
Subject: [PATCH] easy way to use squashfs pseudofile: allows to override mode
 uid gid of files in the SRM

When using a non-root user to execute sysrescue-customize with the srm building function,
you won't have the rights to create files owned by root. When you want to keep the build_into_srm
dir in a git tree, you won't be able to store the file mode there. But using a specific file
mode is important for example for /root/.ssh

The mksquashfs pseudo file allows to solve this by overriding individual file modes like this:

cat <<EOF >recipe_dir/build_into_srm/.squashfs-pseudo
/root/.ssh m 700 root root
/root/.ssh/authorized_keys m 600 root root
EOF
---
 .../share/sysrescue/bin/sysrescue-customize    | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/airootfs/usr/share/sysrescue/bin/sysrescue-customize b/airootfs/usr/share/sysrescue/bin/sysrescue-customize
index eb4d9ff..f1338e1 100755
--- a/airootfs/usr/share/sysrescue/bin/sysrescue-customize
+++ b/airootfs/usr/share/sysrescue/bin/sysrescue-customize
@@ -506,16 +506,28 @@ create_srm()
     fi
 
     local squashfs_options=""
+    local squashfs_exclude=""
+
+    # did the user specify a "pseudo-file"? a list with mode, uid, gid etc. overrides for files
+    if [[ -f "${SRM_DIR}/.squashfs-pseudo" ]]; then
+        squashfs_options+=" -pf \"${SRM_DIR}/.squashfs-pseudo\" "
+
+        # exclude the pseudeo file from the filesystem
+        squashfs_exclude+=" -e .squashfs-pseudo"
+    fi
+    
     # load options for the mksquashfs call from options file
     if [[ -f "${SRM_DIR}/.squashfs-options" ]]; then
         # strip comment lines, replace newlines with spaces to allow using multiple lines easily
-        squashfs_options=$(cat "${SRM_DIR}/.squashfs-options" | grep -v "^#" | tr '\n' ' ')
+        squashfs_options+=$(cat "${SRM_DIR}/.squashfs-options" | grep -v "^#" | tr '\n' ' ')
 
         # exclude the options file from the filesystem
-        # excludes must come after other options, so add it after the content of the options file
-        squashfs_options+=" -e .squashfs-options"
+        squashfs_exclude+=" -e .squashfs-options"
     fi
 
+    # excludes must come after all other options
+    squashfs_options+="$squashfs_exclude"
+    
     # prepare the directory options to be correctly quoted for eval
     local dir_options="\"${SRM_DIR}\" \"${DEST_SRM}\""