WIP: Add concept of "staged" deployment

Add API to write a deployment state to `/run/ostree/staged-deployment`,
along with a systemd service which runs at shutdown time.

Just compile tested, still WIP.

For: coreos/rpm-ostree#40

Makefile-boot.am

@@ -39,7 +39,7 @@ endif
 
 if BUILDOPT_SYSTEMD
 systemdsystemunit_DATA = src/boot/ostree-prepare-root.service \
-	src/boot/ostree-remount.service
+	src/boot/ostree-remount.service src/boot/ostree-deploy-staged.service
 systemdtmpfilesdir = $(prefix)/lib/tmpfiles.d
 dist_systemdtmpfiles_DATA = src/boot/ostree-tmpfiles.conf
 
@@ -65,6 +65,7 @@ EXTRA_DIST += src/boot/dracut/module-setup.sh \
 	src/boot/mkinitcpio/ostree \
 	src/boot/ostree-prepare-root.service \
 	src/boot/ostree-remount.service \
+	src/boot/ostree-deploy-staged.service \
 	src/boot/grub2/grub2-15_ostree \
 	src/boot/grub2/ostree-grub-generator \
 	$(NULL)

src/boot/ostree-deploy-staged.service

@@ -0,0 +1,39 @@
+# Copyright (C) 2018 Red Hat, Inc.
+#
+# 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.
+
+[Unit]
+Description=OSTree Deploy Staged
+DefaultDependencies=no
+ConditionPathExists=/run/ostree-booted
+ConditionPathExists=/run/ostree/staged-deployment
+
+# TODO: Make any failures here very user visible
+# OnFailure=emergency.service
+
+# Go between these two to ensure that any service
+# which might write a file to /etc should be done
+# at this point
+After=shutdown.target
+Before=final.target
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=/usr/lib/ostree/ostree-deploy-staged
+
+[Install]
+WantedBy=final.target

src/libostree/libostree-devel.sym

@@ -22,6 +22,9 @@ LIBOSTREE_2018.3 {
   ostree_deployment_origin_remove_transient_state;
   ostree_sysroot_deployment_set_pinned;
   ostree_deployment_is_pinned;
+  ostree_sysroot_stage_tree;
+  ostree_sysroot_get_staged_deployment;
+  ostree_deployment_is_staged;
 } LIBOSTREE_2018.2;
 
 /* Stub section for the stable release *after* this development one; don't

src/libostree/ostree-cmdprivate.c

@@ -26,7 +26,7 @@
 #include "ostree-core-private.h"
 #include "ostree-repo-pull-private.h"
 #include "ostree-repo-static-delta-private.h"
-#include "ostree-sysroot.h"
+#include "ostree-sysroot-private.h"
 #include "ostree-bootloader-grub2.h"
 
 #include "otutil.h"
@@ -52,7 +52,8 @@ ostree_cmd__private__ (void)
     _ostree_repo_static_delta_dump,
     _ostree_repo_static_delta_query_exists,
     _ostree_repo_static_delta_delete,
-    _ostree_repo_verify_bindings
+    _ostree_repo_verify_bindings,
+    _ostree_sysroot_deploy_staged,
   };
 
   return &table;

src/libostree/ostree-cmdprivate.h

@@ -34,6 +34,7 @@ typedef struct {
   gboolean (* ostree_static_delta_query_exists) (OstreeRepo *repo, const char *delta_id, gboolean *out_exists, GCancellable *cancellable, GError **error);
   gboolean (* ostree_static_delta_delete) (OstreeRepo *repo, const char *delta_id, GCancellable *cancellable, GError **error);
   gboolean (* ostree_repo_verify_bindings) (const char *collection_id, const char *ref_name, GVariant *commit, GError **error);
+  gboolean (* ostree_deploy_staged) (OstreeSysroot *sysroot, GError **error);
 } OstreeCmdPrivateVTable;
 
 /* Note this not really "public", we just export the symbol, but not the header */

src/libostree/ostree-deployment-private.h

@@ -36,6 +36,7 @@ G_BEGIN_DECLS
  * @bootconfig: Bootloader configuration
  * @origin: How to construct an upgraded version of this tree
  * @unlocked: The unlocked state
+ * @staged: TRUE iff this deployment is staged
  */
 struct _OstreeDeployment
 {
@@ -50,6 +51,7 @@ struct _OstreeDeployment
   OstreeBootconfigParser *bootconfig;
   GKeyFile *origin;
   OstreeDeploymentUnlockedState unlocked;
+  gboolean staged;
 };
 
 void _ostree_deployment_set_bootcsum (OstreeDeployment *self, const char *bootcsum);

src/libostree/ostree-deployment.c

@@ -339,3 +339,16 @@ ostree_deployment_is_pinned (OstreeDeployment *self)
     return FALSE;
   return g_key_file_get_boolean (self->origin, OSTREE_ORIGIN_TRANSIENT_GROUP, "pinned", NULL);
 }
+
+/**
+ * ostree_deployment_is_staged:
+ * @self: Deployment
+ *
+ * Returns: `TRUE` if deployment should be "finalized" at shutdown time
+ * Since: 2018.3
+ */
+gboolean
+ostree_deployment_is_staged (OstreeDeployment *self)
+{
+  return self->staged;
+}

src/libostree/ostree-deployment.h

@@ -73,7 +73,8 @@ OstreeBootconfigParser *ostree_deployment_get_bootconfig (OstreeDeployment *self
 _OSTREE_PUBLIC
 GKeyFile *ostree_deployment_get_origin (OstreeDeployment *self);
 
-
+_OSTREE_PUBLIC
+gboolean ostree_deployment_is_staged (OstreeDeployment *self);
 _OSTREE_PUBLIC
 gboolean ostree_deployment_is_pinned (OstreeDeployment *self);
 

src/libostree/ostree-sysroot-cleanup.c

@@ -270,6 +270,13 @@ cleanup_old_deployments (OstreeSysroot       *self,
       g_hash_table_replace (active_boot_checksums, bootcsum, bootcsum);
     }
 
+  /* And also the staged deployment, if any */
+  if (self->staged_deployment)
+    {
+      char *deployment_path = ostree_sysroot_get_deployment_dirpath (self, self->staged_deployment);
+      g_hash_table_replace (active_deployment_dirs, deployment_path, deployment_path);
+    }
+
   /* Find all deployment directories, both active and inactive */
   g_autoptr(GPtrArray) all_deployment_dirs = NULL;
   if (!list_all_deployment_directories (self, &all_deployment_dirs,