virsh: Expose virDomainGetHostnameFlags

Our virsh already has 'domhostname' command. Add '--source'
argument to it so that users can chose between 'lease' and
'agent' sources. Also, implement completer for the argument.

Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>

docs/manpages/virsh.rst

@@ -1797,10 +1797,15 @@ domhostname
 
 .. code-block::
 
-   domhostname domain
+   domhostname domain [--source lease|agent]
 
 Returns the hostname of a domain, if the hypervisor makes it available.
 
+The *--source* argument specifies what data source to use for the
+hostnames, currently 'lease' to read DHCP leases or 'agent' to query
+the guest OS via an agent. If unspecified, driver returns the default
+method available (some drivers support only one type of source).
+
 
 domid
 -----

tools/virsh-completer-domain.c

@@ -316,3 +316,22 @@ virshDomainInterfaceAddrSourceCompleter(vshControl *ctl G_GNUC_UNUSED,
 
     return ret;
 }
+
+
+char **
+virshDomainHostnameSourceCompleter(vshControl *ctl G_GNUC_UNUSED,
+                                   const vshCmd *cmd G_GNUC_UNUSED,
+                                   unsigned int flags)
+{
+    char **ret = NULL;
+    size_t i;
+
+    virCheckFlags(0, NULL);
+
+    ret = g_new0(typeof(*ret), VIRSH_DOMAIN_HOSTNAME_SOURCE_LAST + 1);
+
+    for (i = 0; i < VIRSH_DOMAIN_HOSTNAME_SOURCE_LAST; i++)
+        ret[i] = g_strdup(virshDomainHostnameSourceTypeToString(i));
+
+    return ret;
+}

tools/virsh-completer-domain.h

@@ -58,3 +58,7 @@ char **
 virshDomainInterfaceAddrSourceCompleter(vshControl *ctl,
                                         const vshCmd *cmd,
                                         unsigned int flags);
+
+char ** virshDomainHostnameSourceCompleter(vshControl *ctl,
+                                           const vshCmd *cmd,
+                                           unsigned int flags);

tools/virsh-domain.c

@@ -11742,20 +11742,55 @@ static const vshCmdInfo info_domhostname[] = {
 
 static const vshCmdOptDef opts_domhostname[] = {
     VIRSH_COMMON_OPT_DOMAIN_FULL(VIR_CONNECT_LIST_DOMAINS_ACTIVE),
+    {.name = "source",
+     .type = VSH_OT_STRING,
+     .flags = VSH_OFLAG_NONE,
+     .completer = virshDomainHostnameSourceCompleter,
+     .help = N_("address source: 'lease' or 'agent'")},
     {.name = NULL}
 };
 
+VIR_ENUM_IMPL(virshDomainHostnameSource,
+              VIRSH_DOMAIN_HOSTNAME_SOURCE_LAST,
+              "agent",
+              "lease");
+
 static bool
 cmdDomHostname(vshControl *ctl, const vshCmd *cmd)
 {
     char *hostname;
     virDomainPtr dom;
     bool ret = false;
+    const char *sourcestr = NULL;
+    int flags = 0; /* Use default value. Drivers can have its own default. */
 
     if (!(dom = virshCommandOptDomain(ctl, cmd, NULL)))
         return false;
 
-    hostname = virDomainGetHostname(dom, 0);
+    if (vshCommandOptStringReq(ctl, cmd, "source", &sourcestr) < 0)
+        goto error;
+
+    if (sourcestr) {
+        int source = virshDomainHostnameSourceTypeFromString(sourcestr);
+
+        if (source < 0) {
+            vshError(ctl, _("Unknown data source '%s'"), sourcestr);
+            goto error;
+        }
+
+        switch ((virshDomainHostnameSource) source) {
+        case VIRSH_DOMAIN_HOSTNAME_SOURCE_AGENT:
+            flags |= VIR_DOMAIN_GET_HOSTNAME_AGENT;
+            break;
+        case VIRSH_DOMAIN_HOSTNAME_SOURCE_LEASE:
+            flags |= VIR_DOMAIN_GET_HOSTNAME_LEASE;
+            break;
+        case VIRSH_DOMAIN_HOSTNAME_SOURCE_LAST:
+            break;
+        }
+    }
+
+    hostname = virDomainGetHostname(dom, flags);
     if (hostname == NULL) {
         vshError(ctl, "%s", _("failed to get hostname"));
         goto error;

tools/virsh-domain.h

@@ -30,4 +30,12 @@ typedef struct virshDomainEventCallback virshDomainEventCallback;
 
 extern virshDomainEventCallback virshDomainEventCallbacks[];
 
+typedef enum {
+    VIRSH_DOMAIN_HOSTNAME_SOURCE_AGENT,
+    VIRSH_DOMAIN_HOSTNAME_SOURCE_LEASE,
+    VIRSH_DOMAIN_HOSTNAME_SOURCE_LAST
+} virshDomainHostnameSource;
+
+VIR_ENUM_DECL(virshDomainHostnameSource);
+
 extern const vshCmdDef domManagementCmds[];