builder: Add support for --run to start a command in the build dir

builder/builder-manifest.c

@@ -1758,3 +1758,83 @@ builder_manifest_create_platform (BuilderManifest *self,
 
   return TRUE;
 }
+
+
+gboolean
+builder_manifest_run (BuilderManifest  *self,
+                      BuilderContext   *context,
+                      char            **argv,
+                      int               argc,
+                      GError          **error)
+{
+  g_autoptr(GSubprocessLauncher) launcher = NULL;
+  g_autoptr(GSubprocess) subp = NULL;
+  g_autoptr(GPtrArray) args = NULL;
+  g_autofree char *commandline = NULL;
+  g_autofree char *build_dir_path = NULL;
+  g_autofree char *ccache_dir_path = NULL;
+  g_auto(GStrv) env = NULL;
+  g_auto(GStrv) build_args = NULL;
+  int i;
+
+  if (!gs_file_ensure_directory (builder_context_get_build_dir (context), TRUE,
+                                 NULL, error))
+    return FALSE;
+
+  args = g_ptr_array_new_with_free_func (g_free);
+  g_ptr_array_add (args, g_strdup ("xdg-app"));
+  g_ptr_array_add (args, g_strdup ("build"));
+
+  build_dir_path = g_file_get_path (builder_context_get_build_dir (context));
+  g_ptr_array_add (args, g_strdup_printf ("--bind-mount=/run/build=%s", build_dir_path));
+
+  if (g_file_query_exists (builder_context_get_ccache_dir (context), NULL))
+    {
+      ccache_dir_path = g_file_get_path (builder_context_get_ccache_dir (context));
+      g_ptr_array_add (args, g_strdup_printf ("--bind-mount=/run/ccache=%s", ccache_dir_path));
+    }
+
+  build_args = builder_options_get_build_args (self->build_options, context);
+
+  if (build_args)
+    {
+      for (i = 0; build_args[i] != NULL; i++)
+        g_ptr_array_add (args, g_strdup (build_args[i]));
+    }
+
+  env = builder_options_get_env (self->build_options, context);
+  if (env)
+    {
+      for (i = 0; env[i] != NULL; i++)
+        g_ptr_array_add (args, g_strdup_printf ("--env=%s", env[i]));
+    }
+
+  /* Inherit all finish args except the filesystem ones so the
+   * command gets the same access as the final app */
+  if (self->finish_args)
+    {
+      for (i = 0; self->finish_args[i] != NULL; i++)
+        {
+          const char *arg = self->finish_args[i];
+          if (!g_str_has_prefix (arg, "--filesystem"))
+            g_ptr_array_add (args, g_strdup (arg));
+        }
+    }
+
+  g_ptr_array_add (args, g_file_get_path (builder_context_get_app_dir (context)));
+
+  for (i = 0; i < argc; i++)
+    g_ptr_array_add (args, g_strdup (argv[i]));
+  g_ptr_array_add (args, NULL);
+
+  commandline = g_strjoinv (" ", (char **) args->pdata);
+
+  if (!execvp ((char *)args->pdata[0], (char **)args->pdata))
+    {
+      g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errno), "Unable to start xdg-app build");
+      return FALSE;
+    }
+
+  /* Not reached */
+  return TRUE;
+}

builder/builder-manifest.h

@@ -62,6 +62,11 @@ gboolean        builder_manifest_build             (BuilderManifest  *self,
                                                     BuilderCache     *cache,
                                                     BuilderContext   *context,
                                                     GError          **error);
+gboolean        builder_manifest_run               (BuilderManifest  *self,
+                                                    BuilderContext   *context,
+                                                    char            **argv,
+                                                    int               argc,
+                                                    GError          **error);
 void            builder_manifest_checksum          (BuilderManifest *self,
                                                     BuilderCache    *cache,
                                                     BuilderContext *context);

builder/xdg-app-builder-main.c

@@ -34,6 +34,7 @@
 
 static gboolean opt_verbose;
 static gboolean opt_version;
+static gboolean opt_run;
 static gboolean opt_disable_cache;
 static gboolean opt_download_only;
 static gboolean opt_build_only;
@@ -51,6 +52,7 @@ static char **opt_key_ids;
 static GOptionEntry entries[] = {
   { "verbose", 'v', 0, G_OPTION_ARG_NONE, &opt_verbose, "Print debug information during command processing", NULL },
   { "version", 0, 0, G_OPTION_ARG_NONE, &opt_version, "Print version information and exit", NULL },
+  { "run", 0, 0, G_OPTION_ARG_NONE, &opt_run, "Run a command in the build directory", NULL },
   { "ccache", 0, 0, G_OPTION_ARG_NONE, &opt_ccache, "Use ccache", NULL },
   { "disable-cache", 0, 0, G_OPTION_ARG_NONE, &opt_disable_cache, "Disable cache", NULL },
   { "disable-download", 0, 0, G_OPTION_ARG_NONE, &opt_disable_download, "Don't download any new sources", NULL },
@@ -216,13 +218,6 @@ main (int    argc,
   base_dir = g_file_new_for_path (g_get_current_dir ());
   app_dir = g_file_new_for_path (app_dir_path);
 
-  if (g_file_query_exists (app_dir, NULL) && !directory_is_empty (app_dir_path))
-    {
-      g_printerr ("App dir '%s' is not empty. Please delete "
-                  "the existing contents.\n", app_dir_path);
-      return 1;
-    }
-
   build_context = builder_context_new (base_dir, app_dir);
 
   builder_context_set_keep_build_dirs (build_context, opt_keep_build_dirs);
@@ -234,6 +229,34 @@ main (int    argc,
       return 1;
     }
 
+  if (opt_run)
+    {
+      if (argc == 3)
+        return usage (context, "Program to run must be specified");
+
+      if (!g_file_query_exists (app_dir, NULL) ||
+          directory_is_empty (app_dir_path))
+        {
+          g_printerr ("App dir '%s' is empty or doesn't exist.\n", app_dir_path);
+          return 1;
+        }
+
+      if (!builder_manifest_run (manifest, build_context, argv + 3, argc - 3, &error))
+        {
+          g_printerr ("Error running %s: %s\n", argv[3], error->message);
+          return 1;
+        }
+
+      return 0;
+    }
+
+  if (g_file_query_exists (app_dir, NULL) && !directory_is_empty (app_dir_path))
+    {
+      g_printerr ("App dir '%s' is not empty. Please delete "
+                  "the existing contents.\n", app_dir_path);
+      return 1;
+    }
+
   if (!builder_manifest_start (manifest, build_context, &error))
     {
       g_print ("Failed to init: %s\n", error->message);

doc/xdg-app-builder.xml

@@ -532,6 +532,16 @@
                 </para></listitem>
             </varlistentry>
 
+            <varlistentry>
+                <term><option>--run</option></term>
+
+                <listitem><para>
+                  Run a command in a sandbox based on the build dir. This starts xdg-app build, with some extra
+                  arguments to give the same environment as the build, and the same permissions the final app
+                  will have.
+                </para></listitem>
+            </varlistentry>
+
             <varlistentry>
                 <term><option>--download-only</option></term>