implement file-read api call via guest-agent

this api call reads a file via the guest agent,
(in 1MB chunks) but is limited to 16MiB (for now)

if the file is bigger, the output gets truncated and a
'truncated' flag is set in the return object

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
This commit is contained in:
Dominik Csapak 2018-06-26 14:15:48 +02:00 committed by Thomas Lamprecht
parent 520884deca
commit bb14060a1c

View File

@ -12,6 +12,9 @@ use JSON;
use base qw(PVE::RESTHandler);
# max size for file-read over the api
my $MAX_READ_SIZE = 16 * 1024 * 1024; # 16 MiB
# list of commands
# will generate one api endpoint per command
# needs a 'method' property and optionally a 'perms' property (default VM.Monitor)
@ -114,6 +117,7 @@ __PACKAGE__->register_method({
push @$cmds, qw(
exec
exec-status
file-read
set-user-password
);
@ -362,4 +366,76 @@ __PACKAGE__->register_method({
return $res;
}});
__PACKAGE__->register_method({
name => 'file-read',
path => 'file-read',
method => 'GET',
protected => 1,
proxyto => 'node',
description => "Reads the given file via guest agent. Is limited to $MAX_READ_SIZE bytes.",
permissions => { check => [ 'perm', '/vms/{vmid}', [ 'VM.Monitor' ]]},
parameters => {
additionalProperties => 0,
properties => {
node => get_standard_option('pve-node'),
vmid => get_standard_option('pve-vmid', {
completion => \&PVE::QemuServer::complete_vmid_running }),
file => {
type => 'string',
description => 'The path to the file'
},
},
},
returns => {
type => 'object',
description => "Returns an object with a `content` property.",
properties => {
content => {
type => 'string',
description => "The content of the file, maximum $MAX_READ_SIZE",
},
truncated => {
type => 'boolean',
optional => 1,
description => "If set to 1, the output is truncated and not complete"
}
},
},
code => sub {
my ($param) = @_;
my $vmid = $param->{vmid};
my $qgafh = agent_cmd($vmid, "file-open", { path => $param->{file} }, "can't open file");
my $bytes_left = $MAX_READ_SIZE;
my $eof = 0;
my $read_size = 1024*1024;
my $content = "";
while ($bytes_left > 0 && !$eof) {
my $read = PVE::QemuServer::vm_mon_cmd($vmid, "guest-file-read", handle => $qgafh, count => int($read_size));
check_agent_error($read, "can't read from file");
$content .= decode_base64($read->{'buf-b64'});
$bytes_left -= $read->{count};
$eof = $read->{eof} // 0;
}
my $res = PVE::QemuServer::vm_mon_cmd($vmid, "guest-file-close", handle => $qgafh);
check_agent_error($res, "can't close file", 1);
my $result = {
content => $content,
'bytes-read' => ($MAX_READ_SIZE-$bytes_left),
};
if (!$eof) {
warn "agent file-read: reached maximum read size: $MAX_READ_SIZE bytes. output might be truncated.\n";
$result->{truncated} = 1;
}
return $result;
}});
1;