1 TODO list for libguestfs
2 ======================================================================
4 This list contains random ideas and musings on features we could add
5 to libguestfs in future.
12 Ideas for the Python bindings:
13 https://www.redhat.com/archives/fedora-virt/2009-April/msg00114.html
18 Originally we had intended to implement an NFS server inside the
19 appliance, which would allow the guest filesystems to be mounted on
20 the host, and large changes to be made. We eventually rejected the
21 idea of using NFS, partly because it requires root to mount
22 filesystems in the host, and partly because of problems handling UID
23 mappings between host and guest filesystem.
25 Then we look at implementing an FTP server instead. FTP clients are
26 widely available for many languages, don't require root, and don't
27 have any UID mapping problems. However there is the problem of
28 getting the TCP connection into the guest, and that FTP requires a
29 secondary data connection either in or out of the guest (the NFS
30 situation is even more dire).
32 Thirdly we looked at implementing a FUSE-based filesystem. This is
33 plausible - it could be implemented just by adding the additional FUSE
34 operations to the standard guestfs(3) API, and then implementing a
35 simple FUSE daemon. (The FUSE website has some very helpful
36 documentation and examples). I [RWMJ] am not particularly convinced
37 that a FUSE-based filesystem would really be useful to anyone, but am
38 prepared to accept patches if someone does all the work.
40 See also the mountlo project:
41 http://sourceforge.net/project/showfiles.php?group_id=121684&package_id=150116
46 BufferIn should turn into <char *, int> and simple strings in other
47 languages that can handle 8 bit clean strings.
49 Limit on transfers would still be 2MB for these types.
50 - then implement write-file properly
52 febootstrap / debootstrap inside appliance
53 ------------------------------------------
55 This was originally proposed as a way to install new operating systems
56 in the appliance. However no one has come up with a workable
62 Complete the Haskell bindings (see discussion on haskell-cafe).
67 Complete the bind tests - must test the return values and error cases.
69 virt-inspector - make libvirt XML
70 ---------------------------------
72 It should be possible to generate libvirt XML from virt-inspector
73 data, at least partially. This would be just another output type so:
75 virt-inspector --libvirt guest.img
77 Note that recent versions of libvirt/virt-install allow guests to be
78 imported, so this is not so useful any more.
80 "Standalone/local mode"
81 -----------------------
83 Instead of running guestfsd (the daemon) inside qemu, there should be
84 an option to just run guestfsd directly.
86 The architecture in this mode would look like:
101 (1) This only makes sense if we are running as root.
103 (2) There is no console / kernel messages in this configuration, but
104 we might consider capturing stderr from the daemon.
106 (3) guestfs_config and guestfs_add_drive become no-ops.
108 Obviously in this configuration, commands are run directly on the
109 local machine's disks. You could just run the commands themselves
110 directly, but libguestfs provides a convenient API and language
111 bindings. Also deals with tricky stuff like parsing the output of the
112 LVM commands. Also we get to leverage other code such as
115 This is mainly useful from live CDs, ie. virt-p2v.
117 Should we bother having the daemon at all and just link the guestfsd
118 code directly into libguestfs?
123 [This section should be filed as bugs, but no one seems to care for
124 PPC hosts and the hardware is rapidly becoming obsolete]
126 ppc (32 bit) works with qemu from git, however there is no serial console
128 ppc64 requires extra parameters:
130 however it still fails:
131 invalid/unsupported opcode: 01 - 01 - 1a (06301e83) 00000000018c2738 1
132 invalid bits: 00400000 for opcode: 0b - 19 - 15 (2d746572) 0000000000009230
134 no serial console in ppc or ppc64 because no one can tell us what
135 console=ttyXX option to use
137 Supermin appliance to febootstrap
138 ---------------------------------
140 Supermin appliance functionality should be moved into febootstrap.
142 Ideas for extra commands
143 ------------------------
145 General glibc / core programs:
150 utime / utimes / futimes / futimens / l..
152 some sort of alloc/fallocate/posix_fallocate call to create empty space
182 Allow swap space from the guest to be used. Is it a good idea?
184 Other initrd-* commands
185 -----------------------
192 Simple editing of configuration files
193 -------------------------------------
195 Some easy non-Augeas methods to edit configuration files.
198 replace /etc/file key value
200 which would look in /etc/file for any instances of
206 and replace them with
212 That would solve about 50% of reconfiguration needs, and for the
213 rest you'd use Augeas, 'download'+'upload' or 'edit'.
215 RWMJ: I had a go at implementing this, but it's quite error-prone to
216 do this sort of editing inside the C-based daemon code. It's far
217 better to do it with Augeas, or else to use an external language like
223 Currently we can't do Perl "one-liners". ie. The current syntax for
224 any short Perl one-liner would be:
226 perl -MSys::Guestfs -e '$g = Sys::Guestfs->new(); $g->add_drive ("foo"); $g->launch; $g->wait_ready; $g->mount ("/dev/sda1", "/"); ....'
228 You can see we're well beyond a single line just getting to the point
229 of adding drives and mounting.
233 $h = create ($filename, \"/dev/sda1\" => \"/\");
235 $h = create ([$file1, $file2], \"/dev/sda1\" => \"/\");
237 To mount read-only, add C<ro =E<gt> 1> like this:
239 $h = create ($filename, \"/dev/sda1\" => \"/\", ro => 1);
241 which is equivalent to the following sequence of calls:
243 $h = Sys::Guestfs->new ();
244 $h->set_autosync (1);
245 $h->add_drive_ro ($filename);
248 $h->mount_ro (\"/dev/sda1\", \"/\");
250 Command-line form would be:
252 perl -MSys::Guestfs=:all -e '$_=create("guest.img", "/dev/sda1" => "/"); $_->cat ("/etc/fstab");'
254 That's not brief enough for one-liners, so we could have an extra
255 autogenerated module which creates a Sys::Guestfs handle singleton
256 (the handle is an implicit global variable as in guestfish), eg:
258 perl -MSys::Guestfs::One -e 'inspect("guest.img"); cat ("/etc/fstab");'
260 How would editing files work?