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

Pavel Grunt pgrunt at redhat.com
Thu Mar 2 06:43:12 UTC 2017


On Wed, 2017-03-01 at 15:36 -0600, Jonathon Jongsma wrote:
> 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;
>       }
>     }
sure

> 
>     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.
ok, i will move them
> 
> > {
> > +            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:

true, I will change it

> 
> $ 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

Thank you for the review!
Pavel




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