[libvirt] [PATCH v1 2/2] network: Introduce start and shutdown hooks
Michal Privoznik
mprivozn at redhat.com
Fri Jan 31 16:43:55 UTC 2014
There might be some use cases, where user wants to prepare the host or
its environment prior to starting a network and do some cleanup after
the network has been shut down. Consider all the functionality that
libvirt doesn't currently have as an example what a hook script can
possibly do.
Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
docs/hooks.html.in | 43 +++++++++++++++++++++++++++++--------------
src/network/bridge_driver.c | 29 +++++++++++++++++++++++++++++
src/util/virhook.c | 10 +++++++++-
src/util/virhook.h | 8 ++++++++
4 files changed, 75 insertions(+), 15 deletions(-)
diff --git a/docs/hooks.html.in b/docs/hooks.html.in
index f0f692b..b950031 100644
--- a/docs/hooks.html.in
+++ b/docs/hooks.html.in
@@ -16,6 +16,7 @@
configuration<br/><br/></li>
<li>A QEMU guest is started or stopped<br/><br/></li>
<li>An LXC guest is started or stopped<br/><br/></li>
+ <li>A network is started or stopped<br/><br/></li>
</ul>
<h2><a name="location">Script location</a></h2>
@@ -44,6 +45,8 @@
Executed when a QEMU guest is started, stopped, or migrated<br/><br/></li>
<li><code>/etc/libvirt/hooks/lxc</code><br /><br/>
Executed when an LXC guest is started or stopped</li>
+ <li><code>/etc/libvirt/hooks/network</code><br /><br/>
+ Executed when a network is started or stopped</li>
</ul>
<br/>
@@ -62,10 +65,11 @@
<h2><a name="arguments">Script arguments</a></h2>
<p>The hook scripts are called with specific command line arguments,
depending upon the script, and the operation being performed.</p>
- <p>The guest hook scripts, qemu and lxc, are also given the <b>full</b>
- XML description for the domain on their stdin. This includes items
- such the UUID of the domain and its storage information, and is
- intended to provide all the libvirt information the script needs.</p>
+ <p>The guest hook scripts, qemu and lxc, or network hook script are
+ also given the <b>full</b> XML description for the domain on their
+ stdin. This includes items such as the UUID of the domain or network,
+ domain storage information, etc. and is intended to provide all the
+ libvirt information the script needs.</p>
<p>The command line arguments take this approach:</p>
<ol>
@@ -181,23 +185,34 @@
<pre>/etc/libvirt/hooks/lxc guest_name reconnect begin -</pre>
</li>
</ul>
+
+ <h5><a name="network">/etc/libvirt/hooks/network</a></h5>
+ <ul>
+ <li><span class="since">Since 1.2.2</span>, when a network is started,
+ this script is called as:<br/>
+ <pre>/etc/libvirt/hooks/network network_name start - start</pre></li>
+ <li>When a network is shut down, this script is called as:<br/>
+ <pre>/etc/libvirt/hooks/network network_name shutdown - shutdown</pre></li>
+ </ul>
+
<br/>
<h2><a name="execution">Script execution</a></h2>
<ul>
- <li>The "start" operation for the guest hook scripts, qemu and lxc,
+ <li>The "start" operation for the guest and network hook scripts,
executes <b>prior</b> to the guest being created. This allows the
- guest start operation to be aborted if the script returns indicating
- failure.<br/><br/></li>
- <li>The "shutdown" operation for the guest hook scripts, qemu and lxc,
- executes <b>after</b> the guest has stopped. If the hook script
- indicates failure in its return, the shut down of the guest cannot
- be aborted because it has already been performed.<br/><br/></li>
+ guest or network start operation to be aborted if the script returns
+ indicating failure.<br/><br/></li>
+ <li>The "shutdown" operation for the guest and network hook scripts,
+ executes <b>after</b> the guest or network has stopped. If the hook
+ script indicates failure in its return, the shut down of the guest
+ or network cannot be aborted because it has already been performed.
+ <br/><br/></li>
<li>Hook scripts execute in a synchronous fashion. Libvirt waits
for them to return before continuing the given operation.<br/><br/>
- This is most noticeable with the guest start operation, as a lengthy
- operation in the hook script can mean an extended wait for the guest
- to be available to end users.<br/><br/></li>
+ This is most noticeable with the guest or network start operation,
+ as a lengthy operation in the hook script can mean an extended wait
+ for the guest or network to be available to end users.<br/><br/></li>
<li>For a hook script to be utilised, it must have its execute bit set
(ie. chmod o+rx <i>qemu</i>), and must be present when the libvirt
daemon is started.<br/><br/></li>
diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
index 53c2274..2bca5bc 100644
--- a/src/network/bridge_driver.c
+++ b/src/network/bridge_driver.c
@@ -71,6 +71,7 @@
#include "virstring.h"
#include "viraccessapicheck.h"
#include "network_event.h"
+#include "virhook.h"
#define VIR_FROM_THIS VIR_FROM_NETWORK
@@ -2011,6 +2012,23 @@ networkStartNetwork(virNetworkDriverStatePtr driver,
if (virNetworkObjSetDefTransient(network, true) < 0)
goto cleanup;
+ /* Run an early hook to set-up missing devices */
+ if (virHookPresent(VIR_HOOK_DRIVER_NETWORK)) {
+ char *xml = virNetworkDefFormat(network->def, 0);
+ int hookret;
+
+ hookret = virHookCall(VIR_HOOK_DRIVER_NETWORK, network->def->name,
+ VIR_HOOK_NETWORK_OP_START, VIR_HOOK_SUBOP_BEGIN,
+ NULL, xml, NULL);
+ VIR_FREE(xml);
+
+ /*
+ * If the script raised an error abort the launch
+ */
+ if (hookret < 0)
+ goto cleanup;
+ }
+
switch (network->def->forward.type) {
case VIR_NETWORK_FORWARD_NONE:
@@ -2090,6 +2108,17 @@ static int networkShutdownNetwork(virNetworkDriverStatePtr driver,
break;
}
+ /* now that we know it's stopped call the hook if present */
+ if (virHookPresent(VIR_HOOK_DRIVER_NETWORK)) {
+ char *xml = virNetworkDefFormat(network->def, 0);
+
+ /* we can't stop the operation even if the script raised an error */
+ virHookCall(VIR_HOOK_DRIVER_NETWORK, network->def->name,
+ VIR_HOOK_NETWORK_OP_STOPPED, VIR_HOOK_SUBOP_END,
+ NULL, xml, NULL);
+ VIR_FREE(xml);
+ }
+
network->active = 0;
virNetworkObjUnsetDefTransient(network);
return ret;
diff --git a/src/util/virhook.c b/src/util/virhook.c
index 159efdb..5206810 100644
--- a/src/util/virhook.c
+++ b/src/util/virhook.c
@@ -48,12 +48,14 @@ VIR_ENUM_DECL(virHookDaemonOp)
VIR_ENUM_DECL(virHookSubop)
VIR_ENUM_DECL(virHookQemuOp)
VIR_ENUM_DECL(virHookLxcOp)
+VIR_ENUM_DECL(virHookNetworkOp)
VIR_ENUM_IMPL(virHookDriver,
VIR_HOOK_DRIVER_LAST,
"daemon",
"qemu",
- "lxc")
+ "lxc",
+ "network")
VIR_ENUM_IMPL(virHookDaemonOp, VIR_HOOK_DAEMON_OP_LAST,
"start",
@@ -83,6 +85,10 @@ VIR_ENUM_IMPL(virHookLxcOp, VIR_HOOK_LXC_OP_LAST,
"started",
"reconnect")
+VIR_ENUM_IMPL(virHookNetworkOp, VIR_HOOK_NETWORK_OP_LAST,
+ "start",
+ "stopped")
+
static int virHooksFound = -1;
/**
@@ -246,6 +252,8 @@ virHookCall(int driver,
case VIR_HOOK_DRIVER_LXC:
opstr = virHookLxcOpTypeToString(op);
break;
+ case VIR_HOOK_DRIVER_NETWORK:
+ opstr = virHookNetworkOpTypeToString(op);
}
if (opstr == NULL) {
virReportError(VIR_ERR_INTERNAL_ERROR,
diff --git a/src/util/virhook.h b/src/util/virhook.h
index 96bf4cf..05ed3b5 100644
--- a/src/util/virhook.h
+++ b/src/util/virhook.h
@@ -30,6 +30,7 @@ enum virHookDriverType {
VIR_HOOK_DRIVER_DAEMON = 0, /* Daemon related events */
VIR_HOOK_DRIVER_QEMU, /* QEmu domains related events */
VIR_HOOK_DRIVER_LXC, /* LXC domains related events */
+ VIR_HOOK_DRIVER_NETWORK, /* network related events */
VIR_HOOK_DRIVER_LAST,
};
@@ -74,6 +75,13 @@ enum virHookLxcOpType {
VIR_HOOK_LXC_OP_LAST,
};
+enum virHookNetworkOpType {
+ VIR_HOOK_NETWORK_OP_START, /* network is about to start */
+ VIR_HOOK_NETWORK_OP_STOPPED, /* network has stopped */
+
+ VIR_HOOK_NETWORK_OP_LAST,
+};
+
int virHookInitialize(void);
int virHookPresent(int driver);
--
1.8.5.2
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