By using the once_had_no_optargs flag, this change is backwards
compatible for callers (except Haskell, PHP and GObject as discussed
in earlier commit).
The new API splits orderly close into a two-step process:
if (guestfs_shutdown (g) == -1) {
/* handle the error, eg. qemu error */
}
guestfs_close (g);
Note that the explicit shutdown step is only necessary in the case
where you have made changes to the disk image and want to handle write
errors. Read the documentation for further information.
This change also:
- deprecates guestfs_kill_subprocess
- turns guestfs_kill_subprocess into the same as guestfs_shutdown
- changes guestfish and other tools to call shutdown + close
where necessary (not for read-only tools)
- updates documentation
- updates examples
Old KVM can't add /dev/null readonly. Treat /dev/null as a special
case.
We also fix a few tests where /dev/null was being used with
format=qcow2. This was always incorrect behaviour, but qemu appears
to tolerate it.
'del g' is a trap for the unwary. If the handle has any other
references, it does nothing (in fact, it can be actively dangerous if
the user was expecting the appliance to go away). In non-CPython it
can be delayed arbitrarily long.
Using 'g.close()' on the other hand is always safe.
This large commit changes the generator so that optional arguments
can be supported for functions.
The model for arguments (known as the "style") is changed from
(ret, args) to (ret, args, optargs) where optargs is a more limited
list of arguments.
One function has been added which takes optional arguments, it is
"add-drive-opts", modelled as:
(RErr, [String "filename"], #required
[Bool "readonly"; String "format"; String "iface"]) #optional
Note that this function is processed in the library (does not go over
the RPC protocol to the daemon). This has allowed us to simplify
the current implementation by omitting changes related to RPC or the
daemon, although we plan to add these at some point in the future.
From C this function can be called in 3 different ways as in these
examples:
guestfs_add_drive_opts (g, filename,
GUESTFS_ADD_DRIVE_OPTS_READONLY, 1,
GUESTFS_ADD_DRIVE_OPTS_FORMAT, "raw",
-1);
(the argument(s) between 'filename' and '-1' are the optional ones).
guestfs_add_drive_opts_va (g, filename, args);
where 'args' is a va_list. This works like the first version.
struct guestfs_add_drive_opts_argv optargs = {
.bitmask = GUESTFS_ADD_DRIVE_OPTS_READONLY_BITMASK,
.readonly = 1,
}
guestfs_add_drive_opts_argv (g, filename, &optargs);
This last form lets you construct lists of optional arguments, and
is used by guestfish and the language bindings.
In guestfish optional arguments are used like this:
add-drive-opts filename readonly:true
In OCaml these are mapped naturally to OCaml optional arguments, eg:
g#add_drive_opts ~readonly:true filename;
In Perl these are mapped to extra arguments, eg:
$g->add_drive_opts ($filename, readonly => 1);
In Python these are mapped to optional arguments, eg:
g.add_drive_opts ("file", readonly = 1, format = "qcow2")
In Ruby these are mapped to a final hash argument, eg:
g.add_drive_opts("file", {})
g.add_drive_opts("file", :readonly => 1)
g.add_drive_opts("file", :readonly => 1, :iface => "virtio")
In PHP these are mapped to extra parameters. This is not quite
accurate since you cannot omit arbitrary optional parameters, but
there's not much than can be done within the limitations of PHP
as a language.
Unimplemented in: Haskell, C#, Java.
This commit changes guestfs_launch so that it both launches
the appliance and waits until it is ready (ie. the daemon communicates
back to us).
Since we removed the pretence that we could implement a low-level
asynchronous API, the need to call launch() followed by wait_ready()
has looked a bit silly.
Now guestfs_wait_ready() is basically a no-op. It is left in the
API for backwards compatibility. Any calls to guestfs_wait_ready()
can be removed from client code.
