Script to (decrypt encfs and) selectively sync a remote sshfs directory

encfs-rsync.sh

#!/bin/bash
# Script to (decrypt encfs and) selectively sync a remote sshfs directory
 
REMOTEDIR=server:/path/to/some/encfs
LOCALDIR=/path/to/local/directory

MOUNTFUNC=_ssh+encfs 

# verbose
# set -vx
# exit on error
set -e
 
which sshfs >/dev/null || (echo "Error missing required software: sshfs" && exit 1)
which encfs >/dev/null || (echo "Error missing required software: encfs" && exit 1)
which fusermount >/dev/null || (echo "Error missing required software: fusermount" && exit 1)
test -d /dev/shm >/dev/null || (echo "Error missing required directory: /dev/shm" && exit 1)
[[ "$REMOTEDIR" == *:/* ]] || (echo "Error: \$REMOTEDIR is relative path" && exit 1)
[[ "$LOCALDIR" == /* ]] || (echo "Error: \$LOCALDIR is relative path" && exit 1)
 
abspath() {                                               
    cd "$(dirname "$1")"
    printf "%s/%s\n" "$(pwd)" "$(basename "$1")"
}

_sshfs() {
    if [[ $1 = "-u" ]]; then
        fusermount -uz $2
    else
        sshfs -o idmap=user -o reconnect $1 $2
    fi
}
 
_ssh+encfs() {
    if [[ $1 = "-u" ]]; then
        fusermount -uz $2
        fusermount -uz /dev/shm/encfs_tmp
    else
        mkdir -p /dev/shm/encfs_tmp
        sshfs -o idmap=user -o reconnect $1 /dev/shm/encfs_tmp
        encfs /dev/shm/encfs_tmp $2
    fi
}
 
case "$1" in
    init)
        # write remote files to .sync file
        mkdir -p /dev/shm/encfs_decrypted
        $MOUNTFUNC "$REMOTEDIR" /dev/shm/encfs_decrypted
        rsync -rmn --list-only /dev/shm/encfs_decrypted/* "$LOCALDIR" | \
            awk '{print $5}' > "$(dirname $0)/.sync"
        $MOUNTFUNC -u /dev/shm/encfs_decrypted
        echo "Added file list to .sync file, remove lines you don't need"
        ;;
    sync)
        # update file list in .sync
        [[ ! -f "$(dirname $0)/.sync" ]] && echo "Need to './data.sh init' first" && exit 1
        mkdir -p /dev/shm/encfs_decrypted
        $MOUNTFUNC "$REMOTEDIR" /dev/shm/encfs_decrypted
        rsync -auvrm --files-from="$(dirname $0)/.sync" /dev/shm/encfs_decrypted "$LOCALDIR"
        $MOUNTFUNC -u /dev/shm/encfs_decrypted
        ;;
    mount)
        # mount remote directory to $2
        $MOUNTFUNC "$REMOTEDIR" $(abspath $2)
        ;;
    umount)
        # unmount remote directory at $2
        $MOUNTFUNC -u $(abspath $2)
        ;;
    *)
        echo "Usage: ./$(basename $0) <command>"
        echo "  init         - write available files to .sync file"
        echo "  sync         - update files in .sync from server"
        echo "  mount <dir>  - mount the volume to directory <dir>"
        echo "  umount <dir> - unmount the volume at directory <dir>"
        exit 1
        ;;
esac