compose: Add --ex-unified-core

The "--ex" prefix here means it's an experimental option. A tremendous change
here is that start to support non-uid 0, but there are various things to fix there;
the unpacker for example needs to learn to set imported objects fully based
on the rpmfi information (i.e. default to uid 0, since libarchive gives the
current uid by default).

And even when run as uid 0, there are some bugs, though I'm not sure
of any showstoppers yet.  For example, dracut's `dracut-install` calls
`cp --preserve=xattrs` which fails to copy the `user.ostreemeta` xattrs
from a checkout (it shouldn't be copying that anyways...)

Nevertheless, the infrastructure behind this really helps (is almost a hard
requirement for) the [jigdo effort](#1081).
Which is really only true due to SELinux - we need to import the packages,
then generate the final tree to get the final policy, then use that policy
to relabel all of the packages.

src/app/rpmostree-builtin-compose.c

@@ -29,7 +29,7 @@
 #include <glib/gi18n.h>
 
 static RpmOstreeCommand compose_subcommands[] = {
-  { "tree", RPM_OSTREE_BUILTIN_FLAG_LOCAL_CMD | RPM_OSTREE_BUILTIN_FLAG_REQUIRES_ROOT,
+  { "tree", RPM_OSTREE_BUILTIN_FLAG_LOCAL_CMD,
     "Process a \"treefile\"; install packages and commit the result to an OSTree repository",
     rpmostree_compose_builtin_tree },
   { "install", RPM_OSTREE_BUILTIN_FLAG_LOCAL_CMD | RPM_OSTREE_BUILTIN_FLAG_REQUIRES_ROOT,

src/app/rpmostree-compose-builtin-tree.c

@@ -48,6 +48,7 @@ static gboolean opt_workdir_tmpfs;
 static char *opt_cachedir;
 static gboolean opt_force_nocache;
 static gboolean opt_cache_only;
+static gboolean opt_ex_unified_core;
 static char *opt_proxy;
 static char *opt_output_repodata_dir;
 static char **opt_metadata_strings;
@@ -68,6 +69,7 @@ static GOptionEntry install_option_entries[] = {
   { "force-nocache", 0, 0, G_OPTION_ARG_NONE, &opt_force_nocache, "Always create a new OSTree commit, even if nothing appears to have changed", NULL },
   { "cache-only", 0, 0, G_OPTION_ARG_NONE, &opt_cache_only, "Assume cache is present, do not attempt to update it", NULL },
   { "cachedir", 0, 0, G_OPTION_ARG_STRING, &opt_cachedir, "Cached state", "CACHEDIR" },
+  { "ex-unified-core", 0, 0, G_OPTION_ARG_NONE, &opt_ex_unified_core, "Use new \"unified core\" codepath", NULL },
   { "proxy", 0, 0, G_OPTION_ARG_STRING, &opt_proxy, "HTTP proxy", "PROXY" },
   { "dry-run", 0, 0, G_OPTION_ARG_NONE, &opt_dry_run, "Just print the transaction and exit", NULL },
   { "output-repodata-dir", 0, 0, G_OPTION_ARG_STRING, &opt_output_repodata_dir, "Save downloaded repodata in DIR", "DIR" },
@@ -101,6 +103,8 @@ typedef struct {
   int rootfs_dfd;
   int cachedir_dfd;
   OstreeRepo *repo;
+  OstreeRepo *pkgcache_repo;
+  OstreeRepoDevInoCache *devino_cache;
   char *ref;
   char *previous_checksum;
 
@@ -126,6 +130,8 @@ rpm_ostree_tree_compose_context_free (RpmOstreeTreeComposeContext *ctx)
   glnx_close_fd (&ctx->rootfs_dfd);
   glnx_close_fd (&ctx->cachedir_dfd);
   g_clear_object (&ctx->repo);
+  g_clear_object (&ctx->pkgcache_repo);
+  g_clear_pointer (&ctx->devino_cache, (GDestroyNotify)ostree_repo_devino_cache_unref);
   g_free (ctx->ref);
   g_free (ctx->previous_checksum);
   g_clear_object (&ctx->treefile_parser);
@@ -319,16 +325,6 @@ install_packages_in_root (RpmOstreeTreeComposeContext  *self,
                           GCancellable    *cancellable,
                           GError         **error)
 {
-  /* TODO - uncomment this once we have SELinux working */
-#if 0
-  g_autoptr(OstreeRepo) cache_repo =
-    ostree_repo_create_at (self->cachedir_dfd, "repo",
-                           OSTREE_REPO_MODE_BARE_USER, NULL,
-                           cancellable, error);
-  if (!cache_repo)
-    return FALSE;
-#endif
-
   DnfContext *hifctx = rpmostree_context_get_hif (self->corectx);
   if (opt_proxy)
     dnf_context_set_http_proxy (hifctx, opt_proxy);
@@ -347,8 +343,10 @@ install_packages_in_root (RpmOstreeTreeComposeContext  *self,
   GFile *contextdir = self->treefile_context_dirs->pdata[0];
   dnf_context_set_repo_dir (hifctx, gs_file_get_path_cached (contextdir));
 
-  /* By default, retain packages in addition to metadata with --cachedir */
-  if (opt_cachedir)
+  /* By default, retain packages in addition to metadata with --cachedir, unless
+   * we're doing unified core, in which case the pkgcache repo is the cache.
+   */
+  if (opt_cachedir && !opt_ex_unified_core)
     dnf_context_set_keep_cache (hifctx, TRUE);
   /* For compose, always try to refresh metadata; we're used in build servers
    * where fetching should be cheap. Otherwise, if --cache-only is set, it's
@@ -412,6 +410,35 @@ install_packages_in_root (RpmOstreeTreeComposeContext  *self,
       return FALSE;
   }
 
+  /* For unified core, we have a pkgcache repo. This may be auto-created under
+   * the workdir, or live explicitly in the dir for --cache.
+   */
+  glnx_autofd int host_rootfs_dfd = -1;
+  if (opt_ex_unified_core)
+    {
+      int pkgcache_dfd = self->cachedir_dfd != -1 ? self->cachedir_dfd : self->workdir_dfd;
+      self->pkgcache_repo = ostree_repo_create_at (pkgcache_dfd, "pkgcache-repo",
+                                                   OSTREE_REPO_MODE_BARE_USER, NULL,
+                                                   cancellable, error);
+      if (!self->pkgcache_repo)
+        return FALSE;
+      rpmostree_context_set_repos (self->corectx, self->repo, self->pkgcache_repo);
+      self->devino_cache = ostree_repo_devino_cache_new ();
+
+      /* Ensure that the imported packages are labeled with *a* policy if
+       * possible, even if it's not the final one. This helps avoid duplicating
+       * all of the content.
+       */
+      if (!glnx_opendirat (AT_FDCWD, "/", TRUE, &host_rootfs_dfd, error))
+        return FALSE;
+      g_autoptr(OstreeSePolicy) sepolicy = ostree_sepolicy_new_at (host_rootfs_dfd, cancellable, error);
+      if (!sepolicy)
+        return FALSE;
+      if (ostree_sepolicy_get_name (sepolicy) == NULL)
+        return glnx_throw (error, "Unable to load SELinux policy from /");
+      rpmostree_context_set_sepolicy (self->corectx, sepolicy);
+    }
+
   if (!rpmostree_context_prepare (self->corectx, cancellable, error))
     return FALSE;
 
@@ -475,52 +502,77 @@ install_packages_in_root (RpmOstreeTreeComposeContext  *self,
 
   if (generate_from_previous)
     {
-      if (!rpmostree_generate_passwd_from_previous (self->repo, rootfs_dfd,
+      const char *dest = opt_ex_unified_core ? "usr/etc/" : "etc/";
+      if (!rpmostree_generate_passwd_from_previous (self->repo, rootfs_dfd, dest,
                                                     treefile_dirpath,
                                                     self->previous_root, treedata,
                                                     cancellable, error))
         return FALSE;
     }
 
-  /* Before we install packages, drop a file to suppress the kernel.rpm dracut run.
-   * <https://github.com/systemd/systemd/pull/4174> */
-  const char *kernel_installd_path = "usr/lib/kernel/install.d";
-  if (!glnx_shutil_mkdir_p_at (rootfs_dfd, kernel_installd_path, 0755, cancellable, error))
-    return FALSE;
-  const char skip_kernel_install_data[] = "#!/usr/bin/sh\nexit 77\n";
-  const char *kernel_skip_path = glnx_strjoina (kernel_installd_path, "/00-rpmostree-skip.install");
-  if (!glnx_file_replace_contents_with_perms_at (rootfs_dfd, kernel_skip_path,
-                                                 (guint8*)skip_kernel_install_data,
-                                                 strlen (skip_kernel_install_data),
-                                                 0755, 0, 0,
-                                                 GLNX_FILE_REPLACE_NODATASYNC,
-                                                 cancellable, error))
-    return FALSE;
+  if (opt_ex_unified_core)
+    {
+      if (!rpmostree_context_import (self->corectx, cancellable, error))
+        return FALSE;
+      if (!rpmostree_context_relabel (self->corectx, cancellable, error))
+        return FALSE;
+      rpmostree_context_set_tmprootfs_dfd (self->corectx, rootfs_dfd);
+      if (!rpmostree_context_assemble (self->corectx, cancellable, error))
+        return FALSE;
 
-  /* Now actually run through librpm to install the packages.  Note this bit
-   * will be replaced in the future with a unified core:
-   * https://github.com/projectatomic/rpm-ostree/issues/729
-   */
-  { g_auto(GLnxConsoleRef) console = { 0, };
-    g_autoptr(DnfState) hifstate = dnf_state_new ();
+      /* Now reload the policy from the tmproot, and relabel the pkgcache - this
+       * is the same thing done in rpmostree_context_commit(). But here we want
+       * to ensure our pkgcache labels are accurate, since that will
+       * be important for the ostree-jigdo work.
+       */
+      g_autoptr(OstreeSePolicy) sepolicy = ostree_sepolicy_new_at (rootfs_dfd, cancellable, error);
+      rpmostree_context_set_sepolicy (self->corectx, sepolicy);
 
-    guint progress_sigid = g_signal_connect (hifstate, "percentage-changed",
-                                             G_CALLBACK (on_hifstate_percentage_changed),
-                                             "Installing packages:");
+      if (!rpmostree_context_relabel (self->corectx, cancellable, error))
+        return FALSE;
+    }
+  else
+    {
+      /* The non-unified core path */
 
-    glnx_console_lock (&console);
+      /* Before we install packages, drop a file to suppress the kernel.rpm dracut run.
+       * <https://github.com/systemd/systemd/pull/4174> */
+      const char *kernel_installd_path = "usr/lib/kernel/install.d";
+      if (!glnx_shutil_mkdir_p_at (rootfs_dfd, kernel_installd_path, 0755, cancellable, error))
+        return FALSE;
+      const char skip_kernel_install_data[] = "#!/usr/bin/sh\nexit 77\n";
+      const char *kernel_skip_path = glnx_strjoina (kernel_installd_path, "/00-rpmostree-skip.install");
+      if (!glnx_file_replace_contents_with_perms_at (rootfs_dfd, kernel_skip_path,
+                                                     (guint8*)skip_kernel_install_data,
+                                                     strlen (skip_kernel_install_data),
+                                                     0755, 0, 0,
+                                                     GLNX_FILE_REPLACE_NODATASYNC,
+                                                     cancellable, error))
+        return FALSE;
 
-    if (!libcontainer_prep_dev (rootfs_dfd, error))
-      return FALSE;
+      /* Now actually run through librpm to install the packages.  Note this bit
+       * will be replaced in the future with a unified core:
+       * https://github.com/projectatomic/rpm-ostree/issues/729
+       */
+      g_auto(GLnxConsoleRef) console = { 0, };
+      g_autoptr(DnfState) hifstate = dnf_state_new ();
 
-    if (!dnf_transaction_commit (dnf_context_get_transaction (hifctx),
-                                 dnf_context_get_goal (hifctx),
-                                 hifstate,
-                                 error))
-      return FALSE;
+      guint progress_sigid = g_signal_connect (hifstate, "percentage-changed",
+                                               G_CALLBACK (on_hifstate_percentage_changed),
+                                               "Installing packages:");
 
-    g_signal_handler_disconnect (hifstate, progress_sigid);
-  }
+      glnx_console_lock (&console);
+
+      if (!libcontainer_prep_dev (rootfs_dfd, error))
+        return FALSE;
+
+      if (!dnf_transaction_commit (dnf_context_get_transaction (hifctx),
+                                   dnf_context_get_goal (hifctx),
+                                   hifstate, error))
+        return FALSE;
+
+      g_signal_handler_disconnect (hifstate, progress_sigid);
+    }
 
   if (out_unmodified)
     *out_unmodified = FALSE;
@@ -682,9 +734,32 @@ rpm_ostree_compose_context_new (const char    *treefile_pathstr,
   if (!rpmostree_bwrap_selftest (error))
     return FALSE;
 
+  self->repo = ostree_repo_open_at (AT_FDCWD, opt_repo, cancellable, error);
+  if (!self->repo)
+    return FALSE;
+
   if (opt_workdir_tmpfs)
     g_print ("note: --workdir-tmpfs is deprecated and will be ignored\n");
-  if (!opt_workdir)
+  if (opt_ex_unified_core)
+    {
+      if (opt_workdir)
+        g_printerr ("note: --workdir is ignored for --ex-unified-core\n");
+
+      /* For unified core, our workdir must be underneath the repo tmp/
+       * in order to use hardlinks.  We also really want a bare-user repo.
+       * We hard require that for now, but down the line we may automatically
+       * do a pull-local from the bare-user repo to the archive.
+       */
+      if (ostree_repo_get_mode (self->repo) != OSTREE_REPO_MODE_BARE_USER)
+        return glnx_throw (error, "--ex-unified-core requires a bare-user repository");
+      if (!glnx_mkdtempat (ostree_repo_get_dfd (self->repo), "tmp/rpm-ostree-compose.XXXXXX", 0700,
+                           &self->workdir_tmp, error))
+        return FALSE;
+      /* Note special handling of this aliasing in _finalize() */
+      self->workdir_dfd = self->workdir_tmp.fd;
+
+    }
+  else if (!opt_workdir)
     {
       if (!glnx_mkdtempat (AT_FDCWD, "/var/tmp/rpm-ostree.XXXXXX", 0700, &self->workdir_tmp, error))
         return FALSE;
@@ -698,9 +773,6 @@ rpm_ostree_compose_context_new (const char    *treefile_pathstr,
     }
 
   self->treefile_context_dirs = g_ptr_array_new_with_free_func ((GDestroyNotify)g_object_unref);
-  self->repo = ostree_repo_open_at (AT_FDCWD, opt_repo, cancellable, error);
-  if (!self->repo)
-    return FALSE;
 
   self->treefile_path = g_file_new_for_path (treefile_pathstr);
 
@@ -787,6 +859,14 @@ impl_install_tree (RpmOstreeTreeComposeContext *self,
                    GCancellable    *cancellable,
                    GError         **error)
 {
+  if (getuid () != 0)
+    {
+      if (!opt_ex_unified_core)
+        return glnx_throw (error, "This command requires root privileges");
+      g_printerr ("NOTICE: Running this command as non-root is currently known not to work completely.\n");
+      g_printerr ("NOTICE: Proceeding anyways.\n");
+    }
+
   /* FIXME - is this still necessary? */
   if (fchdir (self->workdir_dfd) != 0)
     return glnx_throw_errno_prefix (error, "fchdir");
@@ -954,7 +1034,8 @@ impl_install_tree (RpmOstreeTreeComposeContext *self,
   /* Start postprocessing */
   if (!rpmostree_treefile_postprocessing (self->rootfs_dfd, self->treefile_context_dirs->pdata[0],
                                           self->serialized_treefile, self->treefile,
-                                          next_version, cancellable, error))
+                                          next_version, opt_ex_unified_core,
+                                          cancellable, error))
     return glnx_prefix_error (error, "Postprocessing");
 
   /* Until here, we targeted "rootfs.tmp" in the working directory. Most
@@ -1031,7 +1112,7 @@ impl_commit_tree (RpmOstreeTreeComposeContext *self,
 
   if (!rpmostree_rootfs_postprocess_common (self->rootfs_dfd, cancellable, error))
     return EXIT_FAILURE;
-  if (!rpmostree_postprocess_final (self->rootfs_dfd, self->treefile,
+  if (!rpmostree_postprocess_final (self->rootfs_dfd, self->treefile, opt_ex_unified_core,
                                     cancellable, error))
     return EXIT_FAILURE;
 
@@ -1164,7 +1245,7 @@ rpmostree_compose_builtin_postprocess (int             argc,
     return EXIT_FAILURE;
   if (!rpmostree_rootfs_postprocess_common (rootfs_dfd, cancellable, error))
     return EXIT_FAILURE;
-  if (!rpmostree_postprocess_final (rootfs_dfd, treefile,
+  if (!rpmostree_postprocess_final (rootfs_dfd, treefile, opt_ex_unified_core,
                                     cancellable, error))
     return EXIT_FAILURE;
   return EXIT_SUCCESS;

src/libpriv/rpmostree-passwd-util.c

@@ -873,6 +873,7 @@ concat_passwd_file (int              rootfs_fd,
 
 static gboolean
 _data_from_json (int              rootfs_dfd,
+                 const char      *dest,
                  GFile           *treefile_dirpath,
                  JsonObject      *treedata,
                  RpmOstreePasswdMigrateKind kind,
@@ -921,7 +922,7 @@ _data_from_json (int              rootfs_dfd,
   *out_found = TRUE;
 
   const char *filebasename = passwd ? "passwd" : "group";
-  const char *target_etc_filename = glnx_strjoina ("etc/", filebasename);
+  const char *target_etc_filename = glnx_strjoina (dest, filebasename);
   g_autoptr(FILE) dest_stream = open_file_stream_write_at (rootfs_dfd, target_etc_filename, "w", error);
   if (!dest_stream)
     return FALSE;
@@ -937,6 +938,7 @@ _data_from_json (int              rootfs_dfd,
 gboolean
 rpmostree_generate_passwd_from_previous (OstreeRepo      *repo,
                                          int              rootfs_dfd,
+                                         const char      *dest,
                                          GFile           *treefile_dirpath,
                                          GFile           *previous_root,
                                          JsonObject      *treedata,
@@ -952,10 +954,10 @@ rpmostree_generate_passwd_from_previous (OstreeRepo      *repo,
    * is really hard because filesystem depends on setup which installs
    * the files...
    */
-  if (!glnx_ensure_dir (rootfs_dfd, "etc", 0755, error))
+  if (!glnx_shutil_mkdir_p_at (rootfs_dfd, dest, 0755, cancellable, error))
     return FALSE;
 
-  if (!_data_from_json (rootfs_dfd, treefile_dirpath,
+  if (!_data_from_json (rootfs_dfd, dest, treefile_dirpath,
                         treedata, RPM_OSTREE_PASSWD_MIGRATE_PASSWD,
                         &found_passwd_data, cancellable, error))
     return FALSE;
@@ -969,7 +971,7 @@ rpmostree_generate_passwd_from_previous (OstreeRepo      *repo,
                                               cancellable, error))
     return FALSE;
 
-  if (!_data_from_json (rootfs_dfd, treefile_dirpath,
+  if (!_data_from_json (rootfs_dfd, dest, treefile_dirpath,
                         treedata, RPM_OSTREE_PASSWD_MIGRATE_GROUP,
                         &found_groups_data, cancellable, error))
     return FALSE;

src/libpriv/rpmostree-passwd-util.h

@@ -57,6 +57,7 @@ rpmostree_passwd_migrate_except_root (int            rootfs_dfd,
 gboolean
 rpmostree_generate_passwd_from_previous (OstreeRepo      *repo,
                                          int              rootfs_dfd,
+                                         const char      *dest,
                                          GFile           *treefile_dirpath,
                                          GFile           *previous_root,
                                          JsonObject      *treedata,
@@ -80,7 +81,7 @@ rpmostree_passwd_cleanup (int rootfs_dfd, GCancellable *cancellable, GError **er
 gboolean
 rpmostree_passwd_prepare_rpm_layering (int       rootfs_dfd,
                                        const char        *merge_passwd_dir,
-                                       gboolean          *out_have_passwd,
+                                       gboolean          *out_have_usrlib_passwd,
                                        GCancellable      *cancellable,
                                        GError  **error);