upgrade: Add support for --pull-only and --deploy-only

This makes it easier to script downloading updates in the background,
and only do deployments just before rebooting.

Partially addresses ostreedev#640

src/ostree/ot-admin-builtin-upgrade.c

@@ -34,6 +34,8 @@
 
 static gboolean opt_reboot;
 static gboolean opt_allow_downgrade;
+static gboolean opt_pull_only;
+static gboolean opt_deploy_only;
 static char *opt_osname;
 static char *opt_override_commit;
 
@@ -42,6 +44,8 @@ static GOptionEntry options[] = {
   { "reboot", 'r', 0, G_OPTION_ARG_NONE, &opt_reboot, "Reboot after a successful upgrade", NULL },
   { "allow-downgrade", 0, 0, G_OPTION_ARG_NONE, &opt_allow_downgrade, "Permit deployment of chronologically older trees", NULL },
   { "override-commit", 0, 0, G_OPTION_ARG_STRING, &opt_override_commit, "Deploy CHECKSUM instead of the latest tree", "CHECKSUM" },
+  { "pull-only", 0, 0, G_OPTION_ARG_NONE, &opt_pull_only, "Do not create a deployment, just download", NULL },
+  { "deploy-only", 0, 0, G_OPTION_ARG_NONE, &opt_deploy_only, "Do not pull, only deploy", NULL },
   { NULL }
 };
 
@@ -64,6 +68,13 @@ ot_admin_builtin_upgrade (int argc, char **argv, GCancellable *cancellable, GErr
                                           &sysroot, cancellable, error))
     goto out;
 
+  if (opt_pull_only && opt_deploy_only)
+    {
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                   "Cannot simultaneously specify --pull-only and --deploy-only");
+      goto out;
+    }
+
   if (!ostree_sysroot_load (sysroot, cancellable, error))
     goto out;
 
@@ -104,22 +115,42 @@ ot_admin_builtin_upgrade (int argc, char **argv, GCancellable *cancellable, GErr
         }
     }
 
-  { g_auto(GLnxConsoleRef) console = { 0, };
-    glnx_console_lock (&console);
+  /* In the pull-only case, we do a cleanup here to ensure that if multiple
+   * commits were pulled, we garbage collect any intermediate data before
+   * pulling more.  This is really a best practice in general, but for maximum
+   * compatiblity, we only do cleanup if a user specifies the new --pull-only
+   * option.  Otherwise, we would break the case of trying to deploy a commit
+   * that isn't directly referenced.
+   */
+  if (opt_pull_only)
+    {
+      if (!ostree_sysroot_cleanup (sysroot, cancellable, error))
+        goto out;
+    }
 
-    if (console.is_tty)
-      progress = ostree_async_progress_new_and_connect (ostree_repo_pull_default_console_progress_changed, &console);
+  if (opt_deploy_only)
+    {
+      /* FIXME - change this to compare the refspec with the origin */
+      changed = TRUE;
+    }
+  else
+    {
+      g_auto(GLnxConsoleRef) console = { 0, };
+      glnx_console_lock (&console);
 
-    if (opt_allow_downgrade)
-      upgraderpullflags |= OSTREE_SYSROOT_UPGRADER_PULL_FLAGS_ALLOW_OLDER;
-
-    if (!ostree_sysroot_upgrader_pull (upgrader, 0, upgraderpullflags,
-                                       progress, &changed,
-                                       cancellable, error))
-      goto out;
+      if (console.is_tty)
+        progress = ostree_async_progress_new_and_connect (ostree_repo_pull_default_console_progress_changed, &console);
+
+      if (opt_allow_downgrade)
+        upgraderpullflags |= OSTREE_SYSROOT_UPGRADER_PULL_FLAGS_ALLOW_OLDER;
+
+      if (!ostree_sysroot_upgrader_pull (upgrader, 0, upgraderpullflags,
+                                         progress, &changed,
+                                         cancellable, error))
+        goto out;
 
-    if (progress)
-      ostree_async_progress_finish (progress);
+      if (progress)
+        ostree_async_progress_finish (progress);
   }
 
   if (!changed)
@@ -128,8 +159,11 @@ ot_admin_builtin_upgrade (int argc, char **argv, GCancellable *cancellable, GErr
     }
   else
     {
-      if (!ostree_sysroot_upgrader_deploy (upgrader, cancellable, error))
-        goto out;
+      if (!opt_pull_only)
+        {
+          if (!ostree_sysroot_upgrader_deploy (upgrader, cancellable, error))
+            goto out;
+        }
 
       if (opt_reboot)
         {