Add 'lxc-enter-namespace' command to virsh

Add a 'lxc-enter-namespace' command which accepts a domain name
and then a command + args to run, attached to the container

eg

  virsh -c lxc:/// lxc-enter-namespace demo -- /bin/ps -auxf

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This commit is contained in:
Daniel P. Berrange 2012-12-21 16:51:33 +00:00
parent 8d63af22de
commit e397f658b0
3 changed files with 104 additions and 0 deletions

View File

@ -133,6 +133,7 @@ virsh_LDADD = \
$(STATIC_BINARIES) \
$(WARN_CFLAGS) \
../src/libvirt.la \
../src/libvirt-lxc.la \
../src/libvirt-qemu.la \
../gnulib/lib/libgnu.la \
$(LIBXML_LIBS) \

View File

@ -43,11 +43,13 @@
#include "conf/domain_conf.h"
#include "console.h"
#include "viralloc.h"
#include "vircommand.h"
#include "virutil.h"
#include "virfile.h"
#include "virjson.h"
#include "virkeycode.h"
#include "virmacaddr.h"
#include "virprocess.h"
#include "virstring.h"
#include "virsh-domain-monitor.h"
#include "virerror.h"
@ -6770,6 +6772,98 @@ cleanup:
return ret;
}
/*
* "lxc-enter-namespace" namespace
*/
static const vshCmdInfo info_lxc_enter_namespace[] = {
{"help", N_("LXC Guest Enter Namespace")},
{"desc", N_("Run an arbitrary lxc guest enter namespace; use at your own risk")},
{NULL, NULL}
};
static const vshCmdOptDef opts_lxc_enter_namespace[] = {
{"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or uuid")},
{"cmd", VSH_OT_ARGV, VSH_OFLAG_REQ, N_("namespace")},
{NULL, 0, 0, NULL}
};
static bool
cmdLxcEnterNamespace(vshControl *ctl, const vshCmd *cmd)
{
virDomainPtr dom = NULL;
bool ret = false;
const vshCmdOpt *opt = NULL;
char **cmdargv = NULL;
size_t ncmdargv = 0;
pid_t pid;
int nfdlist;
int *fdlist;
size_t i;
dom = vshCommandOptDomain(ctl, cmd, NULL);
if (dom == NULL)
goto cleanup;
while ((opt = vshCommandOptArgv(cmd, opt))) {
if (VIR_EXPAND_N(cmdargv, ncmdargv, 1) < 0) {
vshError(ctl, _("%s: %d: failed to allocate argv"),
__FILE__, __LINE__);
}
cmdargv[ncmdargv-1] = opt->data;
}
if (VIR_EXPAND_N(cmdargv, ncmdargv, 1) < 0) {
vshError(ctl, _("%s: %d: failed to allocate argv"),
__FILE__, __LINE__);
}
cmdargv[ncmdargv - 1] = NULL;
if ((nfdlist = virDomainLxcOpenNamespace(dom, &fdlist, 0)) < 0)
goto cleanup;
/* Fork once because we don't want to affect
* virsh's namespace itself
*/
if (virFork(&pid) < 0)
goto cleanup;
if (pid == 0) {
if (virDomainLxcEnterNamespace(dom,
nfdlist,
fdlist,
NULL,
NULL,
0) < 0)
_exit(255);
/* Fork a second time because entering the
* pid namespace only takes effect after fork
*/
if (virFork(&pid) < 0)
_exit(255);
if (pid == 0) {
execv(cmdargv[0], cmdargv);
_exit(255);
} else {
if (virProcessWait(pid, NULL) < 0)
_exit(255);
}
_exit(0);
} else {
for (i = 0 ; i < nfdlist ; i++)
VIR_FORCE_CLOSE(fdlist[i]);
VIR_FREE(fdlist);
if (virProcessWait(pid, NULL) < 0)
goto cleanup;
}
ret = true;
cleanup:
if (dom)
virDomainFree(dom);
VIR_FREE(cmdargv);
return ret;
}
/*
* "dumpxml" command
*/
@ -8760,6 +8854,7 @@ const vshCmdDef domManagementCmds[] = {
{"inject-nmi", cmdInjectNMI, opts_inject_nmi, info_inject_nmi, 0},
{"send-key", cmdSendKey, opts_send_key, info_send_key, 0},
{"send-process-signal", cmdSendProcessSignal, opts_send_process_signal, info_send_process_signal, 0},
{"lxc-enter-namespace", cmdLxcEnterNamespace, opts_lxc_enter_namespace, info_lxc_enter_namespace, 0},
{"managedsave", cmdManagedSave, opts_managedsave, info_managedsave, 0},
{"managedsave-remove", cmdManagedSaveRemove, opts_managedsaveremove,
info_managedsaveremove, 0},

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@ -3056,6 +3056,14 @@ When I<--aysnc> is given, the command waits for timeout whether success or
failed. And when I<--block> is given, the command waits forever with blocking
timeout.
=item B<lxc-enter-namespace> I<domain> -- /path/to/binary [arg1, [arg2, ...]]
Enter the namespace of I<domain> and execute the command C</path/to/binary>
passing the requested args. The binary path is relative to the container
root filesystem, not the host root filesystem. The binary will inherit the
environment variables / console visible to virsh. This command only works
when connected to the LXC hypervisor driver.
=back
=head1 ENVIRONMENT