Add virDomainGetHostname

to query a guests's hostname. Containers like LXC and OpenVZ allow to
set a hostname different from the hosts name and QEMU's guest agent
could provide similar functionality.

include/libvirt/libvirt.h.in

@@ -1540,6 +1540,8 @@ int                     virDomainSetMemoryFlags (virDomainPtr domain,
 int                     virDomainGetMaxVcpus    (virDomainPtr domain);
 int                     virDomainGetSecurityLabel (virDomainPtr domain,
                                                    virSecurityLabelPtr seclabel);
+char *                  virDomainGetHostname    (virDomainPtr domain,
+                                                 unsigned int flags);
 
 typedef enum {
     VIR_DOMAIN_METADATA_DESCRIPTION = 0, /* Operate on <description> */

src/driver.h

@@ -142,6 +142,11 @@ typedef int
                                          unsigned int flags);
 typedef char *
         (*virDrvDomainGetOSType)        (virDomainPtr domain);
+
+typedef char *
+        (*virDrvDomainGetHostname)      (virDomainPtr domain,
+                                         unsigned int flags);
+
 typedef unsigned long long
         (*virDrvDomainGetMaxMemory)     (virDomainPtr domain);
 typedef int
@@ -904,6 +909,7 @@ struct _virDriver {
     virDrvDomainDestroy                 domainDestroy;
     virDrvDomainDestroyFlags            domainDestroyFlags;
     virDrvDomainGetOSType               domainGetOSType;
+    virDrvDomainGetHostname             domainGetHostname;
     virDrvDomainGetMaxMemory            domainGetMaxMemory;
     virDrvDomainSetMaxMemory            domainSetMaxMemory;
     virDrvDomainSetMemory               domainSetMemory;

src/libvirt.c

@@ -18977,3 +18977,48 @@ error:
     virDispatchError(dom->conn);
     return -1;
 }
+
+/**
+ * virDomainGetHostname:
+ * @domain: a domain object
+ * @flags: extra flags; not used yet, so callers should always pass 0
+ *
+ * Get the hostname for that domain.
+ *
+ * Dependent on hypervisor used, this may require a guest agent to be
+ * available.
+ *
+ * Returns the hostname which must be freed by the caller, or
+ * NULL if there was an error.
+ */
+char *
+virDomainGetHostname(virDomainPtr domain, unsigned int flags)
+{
+    virConnectPtr conn;
+
+    VIR_DOMAIN_DEBUG(domain);
+
+    virResetLastError();
+
+    if (!VIR_IS_CONNECTED_DOMAIN(domain)) {
+        virLibDomainError(VIR_ERR_INVALID_DOMAIN, __FUNCTION__);
+        virDispatchError(NULL);
+        return NULL;
+    }
+
+    conn = domain->conn;
+
+    if (conn->driver->domainGetHostname) {
+        char *ret;
+        ret = conn->driver->domainGetHostname (domain, flags);
+        if (!ret)
+            goto error;
+        return ret;
+    }
+
+    virLibConnError(VIR_ERR_NO_SUPPORT, __FUNCTION__);
+
+error:
+    virDispatchError(domain->conn);
+    return NULL;
+}

src/libvirt_public.syms

@@ -544,4 +544,9 @@ LIBVIRT_0.9.13 {
         virDomainSnapshotRef;
 } LIBVIRT_0.9.11;
 
+LIBVIRT_0.9.14 {
+    global:
+        virDomainGetHostname;
+} LIBVIRT_0.9.13;
+
 # .... define new API here using predicted next version number ....