[virt-tools-list] [PATCH virt-viewer 1/2] virt-viewer: Allow more precise VM selection

Jonathon Jongsma jjongsma at redhat.com
Wed Mar 1 21:36:06 UTC 2017


On Fri, 2017-02-24 at 15:57 +0100, Pavel Grunt wrote:
> Theoretically a VM name can be a valid VM id or uuid. In that case
> connecting to the VMs may be problematic since virt-viewer selects
> the VM by its id then by uuid if not found then by its name.
> 
> Introduce new command line options to cover this situation:
>  "--domain-name" to connect to the VM by its name
>  "--id" to connect to the VM by its id
>  "--uuid" to connect to the VM by its uuid
> The options are mutually exclusive
> 
> Resolves: rhbz#1399077
> ---
>  man/virt-viewer.pod | 14 ++++++++
>  src/virt-viewer.c   | 97
> +++++++++++++++++++++++++++++++++++++++++++++++------
>  2 files changed, 101 insertions(+), 10 deletions(-)
> 
> diff --git a/man/virt-viewer.pod b/man/virt-viewer.pod
> index 9abf03c..30af8db 100644
> --- a/man/virt-viewer.pod
> +++ b/man/virt-viewer.pod
> @@ -122,6 +122,20 @@ kiosk-quit option to "on-disconnect" value,
> virt-viewer will quit
>  instead. Please note that --reconnect takes precedence over this
>  option, and will attempt to do a reconnection before it quits.
>  
> +=item --id, --uuid, --domain-name
> +
> +Connect to the virtual machine by its id, uuid or name. These
> options
> +are mutual exclusive. For example the following command may
> sometimes
> +connect to a virtual machine with the id 2 or with the name 2
> (depending
> +on the number of running machines):
> +
> +    virt-viewer 2
> +
> +To always connect to the virtual machine with the name "2" use the
> +"--domain-name" option:
> +
> +    virt-viewer --domain-name 2
> +
>  =back
>  
>  =head1 CONFIGURATION
> diff --git a/src/virt-viewer.c b/src/virt-viewer.c
> index 1f99552..6bc9b6d 100644
> --- a/src/virt-viewer.c
> +++ b/src/virt-viewer.c
> @@ -82,6 +82,46 @@ static gboolean opt_attach = FALSE;
>  static gboolean opt_waitvm = FALSE;
>  static gboolean opt_reconnect = FALSE;
>  
> +typedef enum {
> +    DOMAIN_SELECTION_NONE,
> +    DOMAIN_SELECTION_NAME,
> +    DOMAIN_SELECTION_ID,
> +    DOMAIN_SELECTION_UUID,
> +} DomainSelection;
> +
> +static const gchar* domain_selection_to_opt[] = {
> +    [DOMAIN_SELECTION_NONE] = NULL,
> +    [DOMAIN_SELECTION_NAME] = "--domain-name",
> +    [DOMAIN_SELECTION_ID] = "--id",
> +    [DOMAIN_SELECTION_UUID] = "--uuid",
> +};
> +
> +static DomainSelection domain_selection_type =
> DOMAIN_SELECTION_NONE;
> +
> +static gboolean
> +opt_domain_selection_cb(const gchar *option_name,
> +                        const gchar *value G_GNUC_UNUSED,
> +                        gpointer data G_GNUC_UNUSED,
> +                        GError **error)
> +{
> +    guint i;
> +    if (domain_selection_type != DOMAIN_SELECTION_NONE) {
> +        g_set_error(error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
> +                    "selection type has been already set");
> +        return FALSE;
> +    }
> +
> +    for (i = DOMAIN_SELECTION_NAME; i <=
> G_N_ELEMENTS(domain_selection_to_opt); i++) {
> +        if (g_strcmp0(option_name, domain_selection_to_opt[i]) == 0)
> {
> +            domain_selection_type = i;
> +            return TRUE;
> +        }
> +    }
> +
> +    g_assert_not_reached();
> +    return FALSE;
> +}
> +
>  static void
>  virt_viewer_add_option_entries(VirtViewerApp *self, GOptionContext
> *context, GOptionGroup *group)
>  {
> @@ -96,6 +136,12 @@ virt_viewer_add_option_entries(VirtViewerApp
> *self, GOptionContext *context, GOp
>            N_("Wait for domain to start"), NULL },
>          { "reconnect", 'r', 0, G_OPTION_ARG_NONE, &opt_reconnect,
>            N_("Reconnect to domain upon restart"), NULL },
> +        { "domain-name", '\0', G_OPTION_FLAG_NO_ARG,
> G_OPTION_ARG_CALLBACK, opt_domain_selection_cb,
> +          N_("Select the virtual machine only by its name"), NULL },
> +        { "id", '\0', G_OPTION_FLAG_NO_ARG, G_OPTION_ARG_CALLBACK,
> opt_domain_selection_cb,
> +          N_("Select the virtual machine only by its id"), NULL },
> +        { "uuid", '\0', G_OPTION_FLAG_NO_ARG, G_OPTION_ARG_CALLBACK,
> opt_domain_selection_cb,
> +          N_("Select the virtual machine only by its uuid"), NULL },
>          { G_OPTION_REMAINING, '\0', 0, G_OPTION_ARG_STRING_ARRAY,
> &opt_args,
>            NULL, "-- DOMAIN-NAME|ID|UUID" },
>          { NULL, 0, 0, G_OPTION_ARG_NONE, NULL, NULL, NULL }
> @@ -114,6 +160,7 @@ virt_viewer_local_command_line
> (GApplication   *gapp,
>      gboolean ret = FALSE;
>      VirtViewer *self = VIRT_VIEWER(gapp);
>      VirtViewerApp *app = VIRT_VIEWER_APP(gapp);
> +    const gchar *missing_domkey_fmt = _("\nNo DOMAIN-NAME|ID|UUID
> was specified for '%s'\n\n");
>  
>      ret = G_APPLICATION_CLASS(virt_viewer_parent_class)-
> >local_command_line(gapp, args, status);
>      if (ret)
> @@ -133,7 +180,7 @@ virt_viewer_local_command_line
> (GApplication   *gapp,
>  
>      if (opt_waitvm) {
>          if (!self->priv->domkey) {
> -            g_printerr(_("\nNo DOMAIN-NAME|ID|UUID was specified for
> '--wait'\n\n"));
> +            g_printerr(missing_domkey_fmt, "--wait");
>              ret = TRUE;
>              *status = 1;
>              goto end;
> @@ -142,6 +189,15 @@ virt_viewer_local_command_line
> (GApplication   *gapp,
>          self->priv->waitvm = TRUE;
>      }
>  
> +    if (domain_selection_type != DOMAIN_SELECTION_NONE) {
> +        if (!self->priv->domkey) {
> +            g_printerr(missing_domkey_fmt,
> domain_selection_to_opt[domain_selection_type]);
> +            ret = TRUE;
> +            *status = 1;
> +            goto end;
> +        }
> +    }
> +


This feels a bit like excessive duplication. Could we maybe combine it
with the previous block? Something like (just brainstorming):

    if (opt_waitvm || domain_selection_type != DOMAIN_SELECTION_NONE) {
      if (!domkey) {
        // report error
        goto end;
      }
    }

    self->priv->waitvm = opt_waitvm;


>      virt_viewer_app_set_direct(app, opt_direct);
>      virt_viewer_app_set_attach(app, opt_attach);
>      self->priv->reconnect = opt_reconnect;
> @@ -311,16 +367,31 @@ virt_viewer_lookup_domain(VirtViewer *self)
>          return NULL;
>      }
>  
> -    id = strtol(priv->domkey, &end, 10);
> -    if (id >= 0 && end && !*end) {
> -        dom = virDomainLookupByID(priv->conn, id);
> -    }
> -    if (!dom && virt_viewer_parse_uuid(priv->domkey, uuid) == 0) {
> -        dom = virDomainLookupByUUID(priv->conn, uuid);
> -    }
> -    if (!dom) {
> -        dom = virDomainLookupByName(priv->conn, priv->domkey);
> +    switch (domain_selection_type) {
> +    default: /* DOMAIN_SELECTION_NONE */
> +    case DOMAIN_SELECTION_ID:
> +        id = strtol(priv->domkey, &end, 10);

'id' variable is now technically local to this scope

> +        if (id >= 0 && end && !*end) {
> +            dom = virDomainLookupByID(priv->conn, id);
> +        }
> +        if (domain_selection_type != DOMAIN_SELECTION_NONE) {
> +            break;
> +        }
> +        /* fallthrough */
> +    case DOMAIN_SELECTION_UUID:
> +        if (!dom && virt_viewer_parse_uuid(priv->domkey, uuid) == 0)

Same with uuid.

> {
> +            dom = virDomainLookupByUUID(priv->conn, uuid);
> +        }
> +        if (domain_selection_type != DOMAIN_SELECTION_NONE) {
> +            break;
> +        }
> +        /* fallthrough */
> +    case DOMAIN_SELECTION_NAME:
> +        if (!dom) {
> +            dom = virDomainLookupByName(priv->conn, priv->domkey);
> +        }
>      }
> +
>      return dom;
>  }
>  
> @@ -816,6 +887,12 @@ virt_viewer_initial_connect(VirtViewerApp *app,
> GError **error)
>          if (priv->waitvm) {
>              virt_viewer_app_show_status(app, _("Waiting for guest
> domain to be created"));
>              goto wait;
> +        } else if (domain_selection_type != DOMAIN_SELECTION_NONE) {
> +            g_set_error(&err, VIRT_VIEWER_ERROR,
> VIRT_VIEWER_ERROR_FAILED,
> +                        _("Couldn't find domain '%s' specified by
> '%s'"),
> +                        priv->domkey,
> +                        domain_selection_to_opt[domain_selection_typ
> e]);
> +            goto cleanup;

I'm not sure that this section is necessary. After this change, the
following commands would behave differently, which I think is a bit
unexpected:

$ virt-viewer nonexistent  # opens dialog to choose a vm
$ virt-viewer --domain-name nonexistent  # exits with error


>          } else {
>              VirtViewerWindow *main_window =
> virt_viewer_app_get_main_window(app);
>              if (priv->domkey != NULL)


Jonathon




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