"wekan.database-list-backups" command is broken

[WaryWolf]

Hi,

The snap command to list backups uses an asterisk (*) to attempt to list all files in a directory, which is a feature of some shells, known as file globbing - more info here: http://wiki.bash-hackers.org/syntax/expansion/globs

However this command is run directly and not passed through a shell, so the called executable looks for a file with the literal name of "*", and fails - as can be seen if you check the command with strace:

lstat("/var/snap/wekan/common/db-backups/*", 0x140b690) = -1 ENOENT (No such file or directory)

I did a quick test with a file named "*", which was picked up by the command:

root@wekan:/var/snap/wekan/common/db-backups# python
Python 2.7.12 (default, Dec  4 2017, 14:50:18) 
[GCC 5.4.0 20160609] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> f = open('*', 'w')
>>> f.write("hey hey")
>>> f.close()
>>> exit()

root@wekan:/var/snap/wekan/common/db-backups# ls -lah
total 920K
drwxrwxrwx 2 root root  131 Jan 31 13:30 .
drwxr-xr-x 5 root root 8.0K Jan 31 13:23 ..
-rw-r--r-- 1 root root    7 Jan 31 13:30 *
-rw-r--r-- 1 root root 281K Jan 29 16:59 wekan-20180129T165611.backup
-rw-r--r-- 1 root root 306K Jan 30 14:50 wekan-20180130T145015.backup
-rw-r--r-- 1 root root 309K Jan 31 03:00 wekan-20180131T030001.backup

root@wekan:/var/snap/wekan/common/db-backups# wekan.database-list-backups 
-rw-r--r-- 1 root root 7 Jan 31 13:30 /var/snap/wekan/common/db-backups/*

Obviously, this is not the intended behaviour. I haven't had a chance to test it yet, but I believe changing the database-list-backups command to use ls -al $SNAP_COMMON/db-backups/ instead of ls -ald $SNAP_COMMON/db-backups/* should work. the -d flag is unnecessary since backups are files, not directories.

This testing was done on a Ubuntu 16.04.3 VM, with snapd version 2.29.4.2, if that makes a difference.

Regards, Anthony.