core: Associate branches with remotes, move trigger runs into checkout

Also add --atomic-retarget option to checkout. This does the magical
symlink dance to do atomic swaps between trees.

src/libostree/ostree-sysroot.c

@@ -0,0 +1,121 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright (C) 2012 Colin Walters <walters@verbum.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Author: Colin Walters <walters@verbum.org>
+ */
+
+#include "config.h"
+
+#include <sys/wait.h>
+
+#include "ostree.h"
+#include "otutil.h"
+
+static const char * const sysroot_environ[] = {
+  "HOME=/",
+  "PWD=/",
+  "HOSTNAME=ostreesysroot",
+  "LANG=C",
+  "PATH=/usr/bin:/bin:/usr/sbin:/sbin",
+  "SHELL=/bin/bash",
+  "TERM=vt100",
+  "TMPDIR=/tmp",
+  "TZ=EST5EDT",
+  NULL
+};
+
+const char *const*
+ostree_get_sysroot_environ (void)
+{
+  return (const char *const*)sysroot_environ;
+}
+
+/**
+ * @root: (allow-none): Change to this root; if %NULL, don't chroot
+ *
+ * Triggers are a set of programs to run on a root to regenerate cache
+ * files.  This API call will simply run them against the given root.
+ */
+gboolean
+ostree_run_triggers_in_root (GFile                  *root,
+                             GCancellable           *cancellable,
+                             GError                **error)
+{
+  gboolean ret = FALSE;
+  int estatus;
+  char *rel_triggerdir = NULL;
+  GFile *triggerdir = NULL;
+  GPtrArray *argv = NULL;
+
+  rel_triggerdir = g_build_filename ("usr", "libexec", "ostree", "triggers.d", NULL);
+
+  if (root)
+    triggerdir = g_file_resolve_relative_path (root, rel_triggerdir);
+  else
+    triggerdir = ot_gfile_new_for_path (rel_triggerdir);
+
+  if (g_file_query_exists (triggerdir, cancellable))
+    {
+      argv = g_ptr_array_new ();
+      if (root)
+        {
+          g_ptr_array_add (argv, "linux-user-chroot");
+          g_ptr_array_add (argv, "--unshare-pid");
+          g_ptr_array_add (argv, "--unshare-ipc");
+          /* FIXME - unshare net too */
+          g_ptr_array_add (argv, "--mount-proc");
+          g_ptr_array_add (argv, "/proc");
+          g_ptr_array_add (argv, "--mount-bind");
+          g_ptr_array_add (argv, "/dev");
+          g_ptr_array_add (argv, "/dev");
+          g_ptr_array_add (argv, (char*)ot_gfile_get_path_cached (root));
+        }
+      g_ptr_array_add (argv, "ostree-run-triggers");
+      g_ptr_array_add (argv, NULL);
+
+      if (!g_spawn_sync (NULL, (char**)argv->pdata,
+                         (char**) ostree_get_sysroot_environ (),
+                         G_SPAWN_SEARCH_PATH | G_SPAWN_STDOUT_TO_DEV_NULL,
+                         NULL, NULL, NULL, NULL, &estatus, error))
+        goto out;
+
+      if (WIFEXITED (estatus))
+        {
+          if (WEXITSTATUS (estatus) != 0)
+            {
+              g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                           "Trigger process exited with code %d", (int)WEXITSTATUS (estatus));
+              goto out;
+            }
+        }
+      else
+        {
+          g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                       "Trigger process failed due to signal");
+          goto out;
+        }
+    }
+
+  ret = TRUE;
+ out:
+  g_free (rel_triggerdir);
+  g_clear_object (&triggerdir);
+  ot_clear_ptrarray (&argv);
+  return ret;
+}