app: Add a new alias command

This command lets you create aliases for running apps so that you can
pass "flatpak run" a short string you specify rather than the full app
ID, as discussed here: https://github.com/flatpak/flatpak/pull/4848

app/Makefile.am.inc

@@ -110,6 +110,7 @@ flatpak_SOURCES = \
 	app/flatpak-builtins-create-usb.c \
 	app/flatpak-builtins-kill.c \
 	app/flatpak-builtins-history.c \
+	app/flatpak-builtins-alias.c \
 	app/flatpak-complete.c \
 	app/flatpak-complete.h \
 	app/flatpak-cli-transaction.c \

app/flatpak-builtins-alias.c

@@ -0,0 +1,233 @@
+/*
+ * Copyright © 2022 Matthew Leeds
+ *
+ * This program 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 2.1 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, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *       Matthew Leeds <mwleeds@protonmail.com>
+ */
+
+#include "config.h"
+
+#include <locale.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+
+#include <glib/gi18n.h>
+
+#include "libglnx.h"
+
+#include "flatpak-builtins.h"
+#include "flatpak-builtins-utils.h"
+#include "flatpak-cli-transaction.h"
+#include "flatpak-quiet-transaction.h"
+#include "flatpak-utils-private.h"
+#include "flatpak-error.h"
+#include "flatpak-table-printer.h"
+
+static gboolean opt_remove;
+
+static GOptionEntry options[] = {
+  { "remove", 0, 0, G_OPTION_ARG_NONE, &opt_remove, N_("Remove the specified alias"), NULL },
+  { NULL }
+};
+
+gboolean
+flatpak_builtin_alias (int argc, char **argv, GCancellable *cancellable, GError **error)
+{
+  g_autoptr(GOptionContext) context = NULL;
+  g_autoptr(GPtrArray) dirs = NULL;
+  int i;
+
+  context = g_option_context_new (_("ALIAS [APP] - Add an alias for running the app APP"));
+  g_option_context_set_translation_domain (context, GETTEXT_PACKAGE);
+
+  if (!flatpak_option_context_parse (context, options, &argc, &argv,
+                                     FLATPAK_BUILTIN_FLAG_ALL_DIRS | FLATPAK_BUILTIN_FLAG_OPTIONAL_REPO,
+                                     &dirs, cancellable, error))
+    return FALSE;
+
+  /* Move the user dir to the front so it "wins" in case an app is in more than
+   * one installation */
+  if (dirs->len > 1)
+    {
+      /* Walk through the array backwards so we can safely remove */
+      for (i = dirs->len; i > 0; i--)
+        {
+          FlatpakDir *dir = g_ptr_array_index (dirs, i - 1);
+          if (flatpak_dir_is_user (dir))
+            {
+              g_ptr_array_insert (dirs, 0, g_object_ref (dir));
+              g_ptr_array_remove_index (dirs, i);
+              break;
+            }
+        }
+    }
+
+  if (argc == 1)
+    {
+      g_autoptr(FlatpakTablePrinter) printer = NULL;
+
+      printer = flatpak_table_printer_new ();
+      flatpak_table_printer_set_column_title (printer, 0, _("Alias"));
+      flatpak_table_printer_set_column_title (printer, 1, _("App"));
+      flatpak_table_printer_set_column_title (printer, 2, _("Installation"));
+
+      for (i = 0; i < dirs->len; i++)
+        {
+          FlatpakDir *dir = g_ptr_array_index (dirs, i);
+          g_autoptr(GHashTable) aliases = NULL; /* alias → app-id */
+
+          aliases = flatpak_dir_get_aliases (dir);
+
+          GLNX_HASH_TABLE_FOREACH_KV (aliases, const char *, alias, const char *, app_id)
+            {
+              flatpak_table_printer_add_column (printer, alias);
+              flatpak_table_printer_add_column (printer, app_id);
+              flatpak_table_printer_add_column (printer, flatpak_dir_get_name_cached (dir));
+              flatpak_table_printer_finish_row (printer);
+            }
+        }
+
+      if (flatpak_table_printer_get_current_row (printer) > 0)
+        flatpak_table_printer_print (printer);
+      else if (flatpak_fancy_output ())
+        g_print (_("No aliases\n"));
+    }
+  else if (opt_remove && argc == 2)
+    {
+      const char *alias = argv[1];
+      g_autoptr(GError) saved_error = NULL;
+
+      for (i = 0; i < dirs->len; i++)
+        {
+          g_autoptr(GError) local_error = NULL;
+          FlatpakDir *dir = g_ptr_array_index (dirs, i);
+
+          if (flatpak_dir_remove_alias (dir, alias, &local_error))
+            return TRUE;
+          else
+            {
+              if (g_error_matches (local_error, FLATPAK_ERROR, FLATPAK_ERROR_ALIAS_NOT_FOUND))
+                {
+                  if (saved_error == NULL)
+                    g_propagate_error (&saved_error, g_steal_pointer (&local_error));
+                  continue;
+                }
+              else
+                {
+                  g_propagate_error (error, g_steal_pointer (&local_error));
+                  return FALSE;
+                }
+            }
+        }
+
+      g_propagate_error (error, g_steal_pointer (&saved_error));
+      return FALSE;
+    }
+  else if (!opt_remove && argc == 3)
+    {
+      const char *alias = argv[1];
+      const char *app = argv[2];
+      FlatpakDir *dir_to_use = NULL;
+      g_autoptr(FlatpakDecomposed) current = NULL;
+
+      /* Check if the named app is deployed */
+      for (i = 0; i < dirs->len; i++)
+        {
+          FlatpakDir *dir = g_ptr_array_index (dirs, i);
+          g_autoptr(GFile) deploy = NULL;
+
+          g_clear_pointer (&current, flatpak_decomposed_unref);
+          current = flatpak_dir_current_ref (dir, app, cancellable);
+          if (current)
+            deploy = flatpak_dir_get_if_deployed (dir, current, NULL, cancellable);
+
+          if (deploy != NULL)
+            {
+              dir_to_use = dir;
+              break;
+            }
+        }
+      if (dir_to_use == NULL)
+        return flatpak_fail_error (error, FLATPAK_ERROR_NOT_INSTALLED,
+                                   _("App %s not installed"), app);
+
+      if (!flatpak_dir_make_alias (dir_to_use, current, alias, error))
+        return FALSE;
+    }
+  else
+    return usage_error (context, _("Wrong number of arguments"), error);
+
+  return TRUE;
+}
+
+gboolean
+flatpak_complete_alias (FlatpakCompletion *completion)
+{
+  g_autoptr(GOptionContext) context = NULL;
+  g_autoptr(GPtrArray) dirs = NULL;
+  g_autoptr(GError) error = NULL;
+  int i;
+
+  context = g_option_context_new ("");
+  if (!flatpak_option_context_parse (context, options, &completion->argc, &completion->argv,
+                                     FLATPAK_BUILTIN_FLAG_ALL_DIRS | FLATPAK_BUILTIN_FLAG_OPTIONAL_REPO,
+                                     &dirs, NULL, NULL))
+    return FALSE;
+
+  switch (completion->argc)
+    {
+    case 0:
+    case 1: /* ALIAS */
+      flatpak_complete_options (completion, global_entries);
+      flatpak_complete_options (completion, options);
+      flatpak_complete_options (completion, user_entries);
+
+      if (opt_remove)
+        {
+          for (i = 0; i < dirs->len; i++)
+            {
+              FlatpakDir *dir = g_ptr_array_index (dirs, i);
+              g_autoptr(GHashTable) aliases = NULL; /* alias → app-id */
+
+              aliases = flatpak_dir_get_aliases (dir);
+              GLNX_HASH_TABLE_FOREACH (aliases, const char *, alias)
+                flatpak_complete_word (completion, "%s", alias);
+            }
+        }
+      break;
+    case 2: /* APP */
+      if (!opt_remove)
+        {
+          for (i = 0; i < dirs->len; i++)
+            {
+              FlatpakDir *dir = g_ptr_array_index (dirs, i);
+              g_autoptr(GPtrArray) refs = NULL;
+              refs = flatpak_dir_find_installed_refs (dir, NULL, NULL, NULL,
+                                                      FLATPAK_KINDS_APP,
+                                                      FIND_MATCHING_REFS_FLAGS_NONE,
+                                                      &error);
+              if (refs == NULL)
+                flatpak_completion_debug ("find installed refs error: %s", error->message);
+
+              flatpak_complete_ref_id (completion, refs);
+            }
+        }
+      break;
+    }
+
+  return TRUE;
+}

app/flatpak-builtins.h

@@ -124,6 +124,7 @@ BUILTINPROTO (repair)
 BUILTINPROTO (create_usb)
 BUILTINPROTO (kill)
 BUILTINPROTO (history)
+BUILTINPROTO (alias)
 
 #undef BUILTINPROTO
 

app/flatpak-main.c

@@ -89,6 +89,7 @@ static FlatpakCommand commands[] = {
   { "config", N_("Configure flatpak"), flatpak_builtin_config, flatpak_complete_config },
   { "repair", N_("Repair flatpak installation"), flatpak_builtin_repair, flatpak_complete_repair },
   { "create-usb", N_("Put applications or runtimes onto removable media"), flatpak_builtin_create_usb, flatpak_complete_create_usb },
+  { "alias", N_("Manage short aliases for running applications"), flatpak_builtin_alias, flatpak_complete_alias },
 
   /* translators: please keep the leading newline and space */
   { N_("\n Find applications and runtimes") },

common/flatpak-dir-private.h

@@ -257,6 +257,15 @@ typedef enum {
 #define FLATPAK_HELPER_CONFIGURE_FLAGS_ALL (FLATPAK_HELPER_CONFIGURE_FLAGS_UNSET | \
                                             FLATPAK_HELPER_CONFIGURE_FLAGS_NO_INTERACTION)
 
+typedef enum {
+  FLATPAK_HELPER_CONFIGURE_ALIASES_FLAGS_NONE = 0,
+  FLATPAK_HELPER_CONFIGURE_ALIASES_FLAGS_NO_INTERACTION = 1 << 0,
+  FLATPAK_HELPER_CONFIGURE_ALIASES_FLAGS_REMOVE = 1 << 0,
+} FlatpakHelperConfigureAliasesFlags;
+
+#define FLATPAK_HELPER_CONFIGURE_ALIASES_FLAGS_ALL (FLATPAK_HELPER_CONFIGURE_ALIASES_FLAGS_NO_INTERACTION | \
+                                                    FLATPAK_HELPER_CONFIGURE_ALIASES_FLAGS_REMOVE)
+
 typedef enum {
   FLATPAK_HELPER_UPDATE_REMOTE_FLAGS_NONE = 0,
   FLATPAK_HELPER_UPDATE_REMOTE_FLAGS_NO_INTERACTION = 1 << 0,
@@ -495,6 +504,7 @@ GFile *               flatpak_dir_get_exports_dir                           (Fla
 GFile *               flatpak_dir_get_removed_dir                           (FlatpakDir                    *self);
 GFile *               flatpak_dir_get_sideload_repos_dir                    (FlatpakDir                    *self);
 GFile *               flatpak_dir_get_runtime_sideload_repos_dir            (FlatpakDir                    *self);
+GFile *               flatpak_dir_get_aliases_dir                           (FlatpakDir                    *self);
 GFile *               flatpak_dir_get_if_deployed                           (FlatpakDir                    *self,
                                                                              FlatpakDecomposed             *ref,
                                                                              const char                    *checksum,
@@ -596,6 +606,14 @@ gboolean              flatpak_dir_config_remove_pattern                     (Fla
                                                                              const char                    *key,
                                                                              const char                    *pattern,
                                                                              GError                       **error);
+GHashTable *          flatpak_dir_get_aliases                               (FlatpakDir                    *self);
+gboolean              flatpak_dir_make_alias                                (FlatpakDir                    *self,
+                                                                             FlatpakDecomposed             *current_ref,
+                                                                             const char                    *alias,
+                                                                             GError                       **error);
+gboolean              flatpak_dir_remove_alias                              (FlatpakDir                    *self,
+                                                                             const char                    *alias,
+                                                                             GError                       **error);
 gboolean              flatpak_dir_mark_changed                              (FlatpakDir                    *self,
                                                                              GError                       **error);
 gboolean              flatpak_dir_remove_appstream                          (FlatpakDir                    *self,

common/flatpak-dir.c

@@ -79,6 +79,7 @@
 #define SYSCONF_REMOTES_FILE_EXT ".flatpakrepo"
 
 #define SIDELOAD_REPOS_DIR_NAME "sideload-repos"
+#define ALIASES_DIR_NAME "aliases"
 
 #ifdef USE_SYSTEM_HELPER
 /* This uses a weird Auto prefix to avoid conflicts with later added polkit types.
@@ -2356,6 +2357,30 @@ flatpak_dir_system_helper_call_configure (FlatpakDir   *self,
   return ret != NULL;
 }
 
+static gboolean
+flatpak_dir_system_helper_call_configure_aliases (FlatpakDir   *self,
+                                                  guint         arg_flags,
+                                                  const gchar  *arg_ref,
+                                                  const gchar  *arg_alias,
+                                                  const gchar  *arg_installation,
+                                                  GCancellable *cancellable,
+                                                  GError      **error)
+{
+  if (flatpak_dir_get_no_interaction (self))
+    arg_flags |= FLATPAK_HELPER_CONFIGURE_FLAGS_NO_INTERACTION;
+
+  g_autoptr(GVariant) ret =
+    flatpak_dir_system_helper_call (self, "ConfigureAliases",
+                                    g_variant_new ("(usss)",
+                                                   arg_flags,
+                                                   arg_ref,
+                                                   arg_alias,
+                                                   arg_installation),
+                                    G_VARIANT_TYPE ("()"), NULL,
+                                    cancellable, error);
+  return ret != NULL;
+}
+
 static gboolean
 flatpak_dir_system_helper_call_update_remote (FlatpakDir   *self,
                                               guint         arg_flags,
@@ -3086,6 +3111,12 @@ flatpak_dir_get_runtime_sideload_repos_dir (FlatpakDir *self)
   return g_file_get_child (base, SIDELOAD_REPOS_DIR_NAME);
 }
 
+GFile *
+flatpak_dir_get_aliases_dir (FlatpakDir *self)
+{
+  return g_file_get_child (self->basedir, ALIASES_DIR_NAME);
+}
+
 OstreeRepo *
 flatpak_dir_get_repo (FlatpakDir *self)
 {
@@ -4445,6 +4476,194 @@ flatpak_dir_config_remove_pattern (FlatpakDir *self,
   return flatpak_dir_set_config (self, key, merged_patterns, error);
 }
 
+GHashTable *
+flatpak_dir_get_aliases (FlatpakDir *self)
+{
+  g_autoptr(GHashTable) aliases = NULL; /* alias → app-id */
+  g_autoptr(GFileEnumerator) dir_enum = NULL;
+  g_autoptr(GFile) parent = NULL;
+
+  aliases = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_free);
+
+  if (!flatpak_dir_maybe_ensure_repo (self, NULL, NULL))
+    return g_steal_pointer (&aliases);
+
+  parent = flatpak_dir_get_aliases_dir (self);
+  dir_enum = g_file_enumerate_children (parent,
+                                        G_FILE_ATTRIBUTE_STANDARD_NAME ","
+                                        G_FILE_ATTRIBUTE_STANDARD_TYPE ","
+                                        G_FILE_ATTRIBUTE_STANDARD_SYMLINK_TARGET,
+                                        G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS,
+                                        NULL, NULL);
+  if (dir_enum == NULL)
+    return g_steal_pointer (&aliases);
+
+  while (TRUE)
+    {
+      GFileInfo *info;
+      GFile *path;
+      g_autofree char *path_basename = NULL;
+      const char *target;
+      g_autoptr(GFile) target_file = NULL;
+      g_autofree char *target_basename = NULL;
+
+      if (!g_file_enumerator_iterate (dir_enum, &info, &path, NULL, NULL) ||
+          info == NULL)
+        break;
+
+      /* We expect symlinks to files in $FLATPAK_DIR/exports/bin/ */
+      if (g_file_info_get_file_type (info) != G_FILE_TYPE_SYMBOLIC_LINK)
+        continue;
+
+      path_basename = g_file_get_basename (path);
+      if (path_basename == NULL)
+        continue;
+
+      target = g_file_info_get_symlink_target (info);
+      if (target == NULL)
+        continue;
+
+      target_file = g_file_new_for_path (target);
+      target_basename = g_file_get_basename (target_file);
+      if (target_basename == NULL || !flatpak_is_valid_name (target_basename, -1, NULL))
+        continue;
+
+      g_hash_table_insert (aliases,
+                           g_steal_pointer (&path_basename),
+                           g_steal_pointer (&target_basename));
+    }
+
+  return g_steal_pointer (&aliases);
+}
+
+gboolean
+flatpak_dir_remove_alias (FlatpakDir         *self,
+                          const char         *alias,
+                          GError            **error)
+{
+  g_autoptr(GFile) exports = NULL;
+  g_autoptr(GFile) bindir = NULL;
+  g_autoptr(GFile) runner = NULL;
+  g_autoptr(GFile) aliases = NULL;
+  g_autoptr(GFile) alias_file = NULL;
+  g_autofree char *runner_relpath = NULL;
+  g_autofree char *symlink_target = NULL;
+  g_autofree char *app_id = NULL;
+  g_autoptr(GError) local_error = NULL;
+
+  if (!flatpak_is_valid_alias (alias, error))
+    return FALSE;
+
+  if (flatpak_dir_use_system_helper (self, NULL))
+    {
+      FlatpakHelperConfigureAliasesFlags flags = FLATPAK_HELPER_CONFIGURE_ALIASES_FLAGS_REMOVE;
+      const char *installation = flatpak_dir_get_id (self);
+
+      if (!flatpak_dir_system_helper_call_configure_aliases (self,
+                                                             flags,
+                                                             "", alias,
+                                                             installation ? installation : "",
+                                                             NULL, error))
+        return FALSE;
+
+      return TRUE;
+    }
+
+  aliases = flatpak_dir_get_aliases_dir (self);
+  alias_file = g_file_get_child (aliases, alias);
+
+  /* The caller is responsible for handling FLATPAK_ERROR_ALIAS_NOT_FOUND as needed */
+  if (!g_file_delete (alias_file, NULL, &local_error))
+    {
+      if (g_error_matches (local_error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND))
+        flatpak_fail_error (error, FLATPAK_ERROR_ALIAS_NOT_FOUND,
+                            _("Error removing alias '%s': it does not exist"),
+                            alias);
+      else
+        g_propagate_error (error, g_steal_pointer (&local_error));
+
+      return FALSE;
+    }
+
+  return TRUE;
+}
+
+gboolean
+flatpak_dir_make_alias (FlatpakDir         *self,
+                        FlatpakDecomposed  *current_ref,
+                        const char         *alias,
+                        GError            **error)
+{
+  g_autoptr(GFile) exports = NULL;
+  g_autoptr(GFile) bindir = NULL;
+  g_autoptr(GFile) runner = NULL;
+  g_autoptr(GFile) aliases = NULL;
+  g_autoptr(GFile) alias_file = NULL;
+  g_autofree char *runner_relpath = NULL;
+  g_autofree char *symlink_target = NULL;
+  g_autofree char *app_id = NULL;
+  g_autoptr(GError) local_error = NULL;
+
+  /* If the alias is valid and the app is installed, we create a symlink to the
+   * wrapper script created by flatpak_dir_deploy(). This will be used by the
+   * flatpak run command.
+   */
+
+  if (!flatpak_is_valid_alias (alias, error))
+    return FALSE;
+
+  if (flatpak_dir_use_system_helper (self, NULL))
+    {
+      FlatpakHelperConfigureAliasesFlags flags = 0;
+      const char *installation = flatpak_dir_get_id (self);
+      const char *current_ref_str;
+
+      current_ref_str = flatpak_decomposed_get_ref (current_ref);
+      if (!flatpak_dir_system_helper_call_configure_aliases (self,
+                                                             flags,
+                                                             current_ref_str, alias,
+                                                             installation ? installation : "",
+                                                             NULL, error))
+        return FALSE;
+
+      return TRUE;
+    }
+
+  app_id = flatpak_decomposed_dup_id (current_ref);
+  exports = flatpak_dir_get_exports_dir (self);
+  bindir = g_file_get_child (exports, "bin");
+  runner = g_file_get_child (bindir, app_id);
+
+  if (!g_file_query_exists (runner, NULL))
+    return flatpak_fail_error (error, FLATPAK_ERROR_NOT_INSTALLED,
+                               _("No wrapper script found for %s"), app_id);
+
+  aliases = flatpak_dir_get_aliases_dir (self);
+  alias_file = g_file_get_child (aliases, alias);
+
+  if (g_mkdir_with_parents (flatpak_file_get_path_cached (aliases), 0755) != 0)
+    {
+      glnx_set_error_from_errno (error);
+      return FALSE;
+    }
+
+  runner_relpath = g_file_get_relative_path (self->basedir, runner);
+  symlink_target = g_build_filename ("..", runner_relpath, NULL);
+  if (!g_file_make_symbolic_link (alias_file, symlink_target, NULL, &local_error))
+    {
+      if (g_error_matches (local_error, G_IO_ERROR, G_IO_ERROR_EXISTS))
+        flatpak_fail_error (error, FLATPAK_ERROR_ALIAS_ALREADY_EXISTS,
+                            _("Error making alias '%s': %s"),
+                            alias, local_error->message);
+      else
+        g_propagate_error (error, g_steal_pointer (&local_error));
+
+      return FALSE;
+    }
+
+  return TRUE;
+}
+
 gboolean
 flatpak_dir_mark_changed (FlatpakDir *self,
                           GError    **error)

common/flatpak-error.h

@@ -52,7 +52,7 @@ G_BEGIN_DECLS
  * @FLATPAK_ERROR_EXPORT_FAILED: Exporting data failed. (Since: 1.0.3)
  * @FLATPAK_ERROR_REMOTE_USED: Remote can't be uninstalled. (Since: 1.0.3)
  * @FLATPAK_ERROR_RUNTIME_USED: Runtime can't be uninstalled. (Since: 1.0.3)
- * @FLATPAK_ERROR_INVALID_NAME: Application, runtime or remote name is invalid. (Since: 1.0.3)
+ * @FLATPAK_ERROR_INVALID_NAME: Application, runtime, remote, or alias name is invalid. (Since: 1.0.3)
  * @FLATPAK_ERROR_OUT_OF_SPACE: More disk space needed. (Since: 1.2.0)
  * @FLATPAK_ERROR_WRONG_USER: An operation is being attempted by the wrong user (such as
  *                            root operating on a user installation). (Since: 1.2.0)
@@ -66,6 +66,8 @@ G_BEGIN_DECLS
  * @FLATPAK_ERROR_NOT_AUTHORIZED: An operation tried to access a ref, or information about it that it
  *                                was not authorized. For example, when succesfully authenticating with a
  *                                server but the user doesn't have permissions for a private ref. (Since: 1.7.3)
+ * @FLATPAK_ERROR_ALIAS_NOT_FOUND: The specified alias was not found. (Since: 1.13.4)
+ * @FLATPAK_ERROR_ALIAS_ALREADY_EXISTS: The specified alias was already exists. (Since: 1.13.4)
  *
  * Error codes for library functions.
  */
@@ -95,6 +97,8 @@ typedef enum {
   FLATPAK_ERROR_PERMISSION_DENIED,
   FLATPAK_ERROR_AUTHENTICATION_FAILED,
   FLATPAK_ERROR_NOT_AUTHORIZED,
+  FLATPAK_ERROR_ALIAS_NOT_FOUND,
+  FLATPAK_ERROR_ALIAS_ALREADY_EXISTS,
 } FlatpakError;
 
 /**

common/flatpak-ref-utils-private.h

@@ -169,5 +169,7 @@ char * flatpak_build_app_ref (const char *app,
                               const char *branch,
                               const char *arch);
 
+gboolean flatpak_is_valid_alias (const char *string,
+                                 GError    **error);
 
 #endif /* __FLATPAK_REF_UTILS_H__ */

common/flatpak-ref-utils.c

@@ -1687,3 +1687,66 @@ flatpak_build_app_ref (const char *app,
   return g_build_filename ("app", app, arch, branch, NULL);
 }
 
+/**
+ * flatpak_is_valid_alias:
+ * @string: The string to check
+ * @error: Return location for an error
+ *
+ * Checks if @string is a valid alias for use with the "flatpak alias" and
+ * "flatpak run" commands.
+ *
+ * Per flatpak-alias(1), valid characters are "[A-Z][a-z][0-9]_-" and "-" is
+ * not valid as the first character (to avoid confusion with CLI options).
+ *
+ * Aliases must not exceed 255 characters in length.
+ *
+ * Returns: %TRUE if valid, %FALSE otherwise.
+ */
+gboolean
+flatpak_is_valid_alias (const char *string,
+                        GError    **error)
+{
+  const gchar *s;
+  gssize len;
+
+  g_return_val_if_fail (string != NULL, FALSE);
+
+  len = strlen (string);
+  if (G_UNLIKELY (len == 0))
+    {
+      flatpak_fail_error (error, FLATPAK_ERROR_INVALID_NAME,
+                          _("Alias can't be empty"));
+      return FALSE;
+    }
+
+  if (G_UNLIKELY (len > 255))
+    {
+      flatpak_fail_error (error, FLATPAK_ERROR_INVALID_NAME,
+                          _("Alias can't be longer than 255 characters"));
+      return FALSE;
+    }
+
+  s = string;
+  if (G_UNLIKELY (!is_valid_name_character (*s, FALSE)))
+    {
+      flatpak_fail_error (error, FLATPAK_ERROR_INVALID_NAME,
+                          _("Alias can't start with %c"), *s);
+      return FALSE;
+    }
+  s += 1;
+  while (*s != '\0')
+    {
+      /* Disallowing '.' means that aliases are never valid app IDs which seems
+       * desirable
+       */
+      if (G_UNLIKELY (!is_valid_name_character (*s, TRUE)))
+        {
+          flatpak_fail_error (error, FLATPAK_ERROR_INVALID_NAME,
+                              _("Alias can't contain %c"), *s);
+          return FALSE;
+        }
+      s += 1;
+    }
+
+  return TRUE;
+}

common/flatpak-utils.c

@@ -81,6 +81,8 @@ static const GDBusErrorEntry flatpak_error_entries[] = {
   {FLATPAK_ERROR_PERMISSION_DENIED,     "org.freedesktop.Flatpak.Error.PermissionDenied"}, /* Since: 1.5.1 */
   {FLATPAK_ERROR_AUTHENTICATION_FAILED, "org.freedesktop.Flatpak.Error.AuthenticationFailed"}, /* Since: 1.7.3 */
   {FLATPAK_ERROR_NOT_AUTHORIZED,        "org.freedesktop.Flatpak.Error.NotAuthorized"}, /* Since: 1.7.3 */
+  {FLATPAK_ERROR_ALIAS_NOT_FOUND,       "org.freedesktop.Flatpak.Error.AliasNotFound"}, /* Since: 1.13.4 */
+  {FLATPAK_ERROR_ALIAS_ALREADY_EXISTS,  "org.freedesktop.Flatpak.Error.AliasAlreadyExists"}, /* Since: 1.13.4 */
 };
 
 typedef struct archive FlatpakAutoArchiveRead;

data/org.freedesktop.Flatpak.xml

@@ -269,6 +269,13 @@
       <arg type='s' name='installation' direction='in'/>
     </method>
 
+    <method name="ConfigureAliases">
+      <arg type='u' name='flags' direction='in'/>
+      <arg type='s' name='ref' direction='in'/>
+      <arg type='s' name='alias' direction='in'/>
+      <arg type='s' name='installation' direction='in'/>
+    </method>
+
     <method name="UpdateRemote">
       <arg type='u' name='flags' direction='in'/>
       <arg type='s' name='remote' direction='in'/>

doc/Makefile.am

@@ -63,6 +63,7 @@ man1 = \
 	flatpak-kill.1 			\
 	flatpak-history.1 		\
 	flatpak-spawn.1 		\
+	flatpak-alias.1 		\
 	$(NULL)
 
 man5 = \

doc/flatpak-alias.xml

@@ -0,0 +1,176 @@
+<?xml version='1.0'?> <!--*-nxml-*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
+    "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
+
+<refentry id="flatpak-alias">
+
+    <refentryinfo>
+        <title>flatpak alias</title>
+        <productname>flatpak</productname>
+
+        <authorgroup>
+            <author>
+                <contrib>Developer</contrib>
+                <firstname>Matthew</firstname>
+                <surname>Leeds</surname>
+                <email>mwleeds@protonmail.com</email>
+            </author>
+        </authorgroup>
+    </refentryinfo>
+
+    <refmeta>
+        <refentrytitle>flatpak alias</refentrytitle>
+        <manvolnum>1</manvolnum>
+    </refmeta>
+
+    <refnamediv>
+        <refname>flatpak-alias</refname>
+        <refpurpose>Manage short aliases for running applications</refpurpose>
+    </refnamediv>
+
+    <refsynopsisdiv>
+            <cmdsynopsis>
+                <command>flatpak alias</command>
+                <arg choice="opt" rep="repeat">OPTION</arg>
+                <arg choice="plain">ALIAS</arg>
+                <arg choice="plain">APP</arg>
+            </cmdsynopsis>
+            <cmdsynopsis>
+                <command>flatpak alias</command>
+                <arg choice="opt" rep="repeat">OPTION</arg>
+                <arg choice="opt">--remove</arg>
+                <arg choice="plain">ALIAS</arg>
+            </cmdsynopsis>
+    </refsynopsisdiv>
+
+    <refsect1>
+        <title>Description</title>
+
+        <para>
+          Normally to run a Flatpak app from the command line you specify the full
+          App ID (and optionally the arch and branch) to the
+          <command>flatpak run</command> command. This can be tedious, so the
+          <command>alias</command> command allows you to set up aliases that can
+          be passed to <command>flatpak run</command> instead. Once set up, no
+          additional confirmation prompts are needed each time the alias is used.
+        </para>
+        <para>
+          The <arg choice="plain">APP</arg> argument is the application ID of an
+          installed application. Only the current branch will be used; see
+          <citerefentry><refentrytitle>flatpak-make-current</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+          As with the <command>flatpak run</command> command, if an app is installed
+          both system-wide and per-user, the per-user one will be used unless
+          otherwise specified with <option>--system</option> or <option>--installation</option>.
+        </para>
+        <para>
+          The <arg choice="plain">ALIAS</arg> argument is a string which can only
+          contain the ASCII characters "[A-Z][a-z][0-9]_-" and cannot start with a "-".
+        </para>
+        <para>
+          To list the current set of aliases, run this command without any arguments.
+        </para>
+        <para>
+          Aliases are created as files in an <filename>aliases</filename>
+          subdirectory of the relevant installation directory. However, it is not
+          recommended to add this directory to your <envar>PATH</envar> since
+          Flatpaks cannot handle file arguments like OS packages. For example, a
+          command such as <command>media-player ~/some-file.ogg</command> would not
+          work if the relevant Flatpak doesn't have home directory access. To
+          provide access to particular files specified on the command line, use the
+          <option>--file-forwarding</option> option documented in
+          <citerefentry><refentrytitle>flatpak-run</refentrytitle><manvolnum>2</manvolnum></citerefentry>.
+        </para>
+    </refsect1>
+
+    <refsect1>
+        <title>Options</title>
+
+        <para>The following options are understood:</para>
+
+        <variablelist>
+            <varlistentry>
+                <term><option>-h</option></term>
+                <term><option>--help</option></term>
+
+                <listitem><para>
+                    Show help options and exit.
+                </para></listitem>
+            </varlistentry>
+
+            <varlistentry>
+                <term><option>--remove</option></term>
+
+                <listitem><para>
+                    Instead of adding the specified alias, remove it. In this case
+                    there's no need to specify the <arg choice="plain">APP</arg>.
+                </para></listitem>
+            </varlistentry>
+
+            <varlistentry>
+                <term><option>--user</option></term>
+
+                <listitem><para>
+                    Operate on the per-user installation.
+                </para></listitem>
+            </varlistentry>
+
+            <varlistentry>
+                <term><option>--system</option></term>
+
+                <listitem><para>
+                    Operate on the default system-wide installation.
+                </para></listitem>
+            </varlistentry>
+
+            <varlistentry>
+                <term><option>--installation=NAME</option></term>
+
+                <listitem><para>
+                    Operate on the system-wide installation
+                    specified by <arg choice="plain">NAME</arg> among those defined in
+                    <filename>/etc/flatpak/installations.d/</filename>. Using
+                    <option>--installation=default</option> is equivalent to using
+                    <option>--system</option>.
+                </para></listitem>
+            </varlistentry>
+
+            <varlistentry>
+                <term><option>-v</option></term>
+                <term><option>--verbose</option></term>
+
+                <listitem><para>
+                    Print debug information during command processing.
+                </para></listitem>
+            </varlistentry>
+        </variablelist>
+    </refsect1>
+
+    <refsect1>
+        <title>Examples</title>
+
+        <para>
+            <command>$ flatpak alias</command>
+        </para>
+        <para>
+            <command>$ flatpak alias app-bin org.example.App</command>
+        </para>
+        <para>
+            <command>$ flatpak alias --system org.example.App app-bin</command>
+        </para>
+        <para>
+            <command>$ flatpak alias --remove app-bin</command>
+        </para>
+
+    </refsect1>
+
+    <refsect1>
+        <title>See also</title>
+
+        <para>
+            <citerefentry><refentrytitle>flatpak</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+            <citerefentry><refentrytitle>flatpak-run</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+        </para>
+
+    </refsect1>
+
+</refentry>

doc/flatpak.xml

@@ -287,6 +287,13 @@
                     Copy apps and/or runtimes onto removable media.
                 </para></listitem>
             </varlistentry>
+            <varlistentry>
+                <term><citerefentry><refentrytitle>flatpak-alias</refentrytitle><manvolnum>1</manvolnum></citerefentry></term>
+
+                <listitem><para>
+                    Manage short aliases for running applications.
+                </para></listitem>
+            </varlistentry>
         </variablelist>
 
 

po/POTFILES.in

@@ -1,5 +1,6 @@
 # List of source files containing translatable strings.
 # Please keep this file sorted alphabetically.
+app/flatpak-builtins-alias.c
 app/flatpak-builtins-build-bundle.c
 app/flatpak-builtins-build.c
 app/flatpak-builtins-build-commit-from.c

system-helper/flatpak-system-helper.c

@@ -1177,6 +1177,95 @@ handle_configure (FlatpakSystemHelper   *object,
   return G_DBUS_METHOD_INVOCATION_HANDLED;
 }
 
+/* Note: While this currently only supports creating aliases for apps, the
+ * argument being a full ref rather than an app ID means we can change it to
+ * support runtimes in the future if needed.
+ */
+static gboolean
+handle_configure_aliases (FlatpakSystemHelper   *object,
+                          GDBusMethodInvocation *invocation,
+                          guint                  arg_flags,
+                          const gchar           *arg_ref,
+                          const gchar           *arg_alias,
+                          const gchar           *arg_installation)
+{
+  g_autoptr(FlatpakDir) system = NULL;
+  g_autoptr(GError) error = NULL;
+  g_autoptr(FlatpakDecomposed) ref = NULL;
+  g_autoptr(GFile) deploy = NULL;
+  gboolean remove_alias = (arg_flags & FLATPAK_HELPER_CONFIGURE_ALIASES_FLAGS_REMOVE) != 0;
+
+  g_debug ("ConfigureAliases %u %s %s %s", arg_flags, arg_ref, arg_alias, arg_installation);
+
+  system = dir_get_system (arg_installation, get_sender_pid (invocation), (arg_flags & FLATPAK_HELPER_CONFIGURE_ALIASES_FLAGS_NO_INTERACTION) != 0, &error);
+  if (system == NULL)
+    {
+      g_dbus_method_invocation_return_gerror (invocation, error);
+      return G_DBUS_METHOD_INVOCATION_HANDLED;
+    }
+
+  if ((arg_flags & ~FLATPAK_HELPER_CONFIGURE_ALIASES_FLAGS_ALL) != 0)
+    {
+      g_dbus_method_invocation_return_error (invocation, G_DBUS_ERROR, G_DBUS_ERROR_INVALID_ARGS,
+                                             "Unsupported flags enabled: 0x%x", (arg_flags & ~FLATPAK_HELPER_CONFIGURE_FLAGS_ALL));
+      return G_DBUS_METHOD_INVOCATION_HANDLED;
+    }
+
+  if (!remove_alias)
+    {
+      ref = flatpak_decomposed_new_from_ref (arg_ref, &error);
+      if (ref == NULL)
+        {
+          g_dbus_method_invocation_return_gerror (invocation, error);
+          return G_DBUS_METHOD_INVOCATION_HANDLED;
+        }
+
+      if (!flatpak_decomposed_is_app (ref))
+        {
+          g_dbus_method_invocation_return_error (invocation, G_DBUS_ERROR, G_DBUS_ERROR_INVALID_ARGS,
+                                                 "Invalid ref %s: must be an app", arg_ref);
+          return G_DBUS_METHOD_INVOCATION_HANDLED;
+        }
+
+      deploy = flatpak_dir_get_if_deployed (system, ref, NULL, NULL);
+      if (deploy == NULL)
+        {
+          flatpak_invocation_return_error (invocation, error, "App %s not installed", arg_ref);
+          return G_DBUS_METHOD_INVOCATION_HANDLED;
+        }
+    }
+
+  if (!flatpak_dir_ensure_repo (system, NULL, &error))
+    {
+      g_dbus_method_invocation_return_gerror (invocation, error);
+      return G_DBUS_METHOD_INVOCATION_HANDLED;
+    }
+
+  if (!remove_alias)
+    {
+      if (!flatpak_dir_make_alias (system, ref, arg_alias, &error))
+        {
+          flatpak_invocation_return_error (invocation, error, "Error making alias");
+          return G_DBUS_METHOD_INVOCATION_HANDLED;
+        }
+    }
+  else
+    {
+      /* Here we consider it an error if the alias does not exist */
+      if (!flatpak_dir_remove_alias (system, arg_alias, &error))
+        {
+          flatpak_invocation_return_error (invocation, error, "Error removing alias");
+          return G_DBUS_METHOD_INVOCATION_HANDLED;
+        }
+
+      g_clear_error (&error);
+    }
+
+  flatpak_system_helper_complete_configure_aliases (object, invocation);
+
+  return G_DBUS_METHOD_INVOCATION_HANDLED;
+}
+
 static gboolean
 handle_update_remote (FlatpakSystemHelper   *object,
                       GDBusMethodInvocation *invocation,
@@ -2121,6 +2210,15 @@ flatpak_authorize_method_handler (GDBusInterfaceSkeleton *interface,
 
       polkit_details_insert (details, "key", key);
     }
+  else if (g_strcmp0 (method_name, "ConfigureAliases") == 0)
+    {
+      guint32 flags;
+
+      g_variant_get_child (parameters, 0, "u", &flags);
+
+      action = "org.freedesktop.Flatpak.configure-aliases";
+      no_interaction = (flags & FLATPAK_HELPER_CONFIGURE_FLAGS_NO_INTERACTION) != 0;
+    }
   else if (g_strcmp0 (method_name, "UpdateRemote") == 0)
     {
       const char *remote;
@@ -2223,6 +2321,7 @@ on_bus_acquired (GDBusConnection *connection,
   g_signal_connect (helper, "handle-install-bundle", G_CALLBACK (handle_install_bundle), NULL);
   g_signal_connect (helper, "handle-configure-remote", G_CALLBACK (handle_configure_remote), NULL);
   g_signal_connect (helper, "handle-configure", G_CALLBACK (handle_configure), NULL);
+  g_signal_connect (helper, "handle-configure-aliases", G_CALLBACK (handle_configure_aliases), NULL);
   g_signal_connect (helper, "handle-update-remote", G_CALLBACK (handle_update_remote), NULL);
   g_signal_connect (helper, "handle-remove-local-ref", G_CALLBACK (handle_remove_local_ref), NULL);
   g_signal_connect (helper, "handle-prune-local-repo", G_CALLBACK (handle_prune_local_repo), NULL);

system-helper/org.freedesktop.Flatpak.policy.in

@@ -199,6 +199,21 @@
     </defaults>
   </action>
 
+  <action id="org.freedesktop.Flatpak.configure-aliases">
+    <!-- SECURITY:
+        - Normal users need admin authentication to configure aliases in the
+          system-wide Flatpak installation.
+     -->
+    <description>Configure</description>
+    <message>Authentication is required to configure software installation</message>
+    <icon_name>package-x-generic</icon_name>
+    <defaults>
+      <allow_any>auth_admin</allow_any>
+      <allow_inactive>auth_admin</allow_inactive>
+      <allow_active>auth_admin_keep</allow_active>
+    </defaults>
+  </action>
+
   <action id="org.freedesktop.Flatpak.appstream-update">
     <!-- SECURITY:
           - Normal users do not require admin authentication to update

tests/Makefile-test-matrix.am.inc

@@ -28,6 +28,8 @@ TEST_MATRIX= \
 	tests/test-summaries@system.wrap \
 	tests/test-subset@user.wrap \
 	tests/test-subset@system.wrap \
+	tests/test-alias@user.wrap \
+	tests/test-alias@system.wrap \
 	$(NULL)
 TEST_MATRIX_DIST= \
 	tests/test-basic.sh \
@@ -58,4 +60,5 @@ TEST_MATRIX_EXTRA_DIST= \
 	tests/test-update-portal.sh \
 	tests/test-summaries.sh \
 	tests/test-subset.sh \
+	tests/test-alias.sh \
 	$(NULL)

tests/test-alias.sh

@@ -0,0 +1,77 @@
+#!/bin/bash
+#
+# Copyright (C) 2022 Matthew Leeds <mwleeds@protonmail.com>
+#
+# SPDX-License-Identifier: LGPL-2.0-or-later
+
+set -euo pipefail
+
+. $(dirname $0)/libtest.sh
+
+echo "1..3"
+
+setup_repo
+${FLATPAK} ${U} install -y test-repo org.test.Hello >&2
+
+# List aliases (none)
+${FLATPAK} ${U} alias > aliases
+assert_file_empty aliases
+
+# Make an alias
+${FLATPAK} ${U} alias hello org.test.Hello
+${FLATPAK} ${U} alias > aliases
+if [ x${USE_SYSTEMDIR-} == xyes ]; then
+    assert_file_has_content aliases "hello	org\.test\.Hello	system"
+else
+    assert_file_has_content aliases "hello	org\.test\.Hello	user"
+fi
+
+# Shouldn't be able to make an alias that already exists
+if ${FLATPAK} ${U} alias hello org.test.Hello &> alias-error-log; then
+    assert_not_reached "Should not be able to create an alias that already exists"
+fi
+assert_file_has_content alias-error-log "error: Error making alias 'hello': Error making symbolic link .*: File exists"
+
+# Shouldn't be able to make an alias that for an app that's not installed
+if ${FLATPAK} ${U} alias hello org.test.Bonjour &> alias-error-log; then
+    assert_not_reached "Should not be able to create an alias for an uninstalled app"
+fi
+assert_file_has_content alias-error-log "error: App org.test.Bonjour not installed"
+
+# Remove an alias
+${FLATPAK} ${U} alias --remove hello
+${FLATPAK} ${U} alias > aliases
+assert_file_empty aliases
+
+ok "alias command works"
+
+if ${FLATPAK} ${U} alias .hello org.test.Hello &> alias-error-log; then
+    assert_not_reached "Should not be able to create an alias starting with a period"
+fi
+assert_file_has_content alias-error-log "error: Alias can't start with \."
+
+if ${FLATPAK} ${U} alias org.test.Goodbye org.test.Hello &> alias-error-log; then
+    assert_not_reached "Should not be able to create an alias which contains a period"
+fi
+assert_file_has_content alias-error-log "error: Alias can't contain \."
+
+if ${FLATPAK} ${U} alias 🦋 org.test.Hello &> alias-error-log; then
+    assert_not_reached "Should not be able to create an alias which is a butterfly"
+fi
+# In flatpak_is_valid_alias() we look at the string byte by byte so multi-byte
+# characters don't get printed properly in the error message.
+assert_file_has_content alias-error-log "error: Alias can't start with "
+
+ok "alias command rejects invalid alias characters"
+
+if ${FLATPAK} ${U} alias --remove notarealalias &> alias-error-log; then
+    assert_not_reached "Should not be able to remove an alias that doesn't exist"
+fi
+assert_file_has_content alias-error-log "error: Error removing alias 'notarealalias': it does not exist"
+
+# clean up
+rm aliases alias-error-log
+${FLATPAK} ${U} uninstall -y org.test.Platform org.test.Hello >&2
+${FLATPAK} ${U} remote-delete test-repo >&2
+
+ok "alias --remove command rejects non-existent alias"

tests/test-basic.sh

@@ -71,7 +71,7 @@ for cmd in install update uninstall list info config repair create-usb \
            remote-modify remote-delete remote-ls remote-info build-init \
            build build-finish build-export build-bundle build-import-bundle \
            build-sign build-update-repo build-commit-from repo kill history \
-           mask;
+           mask alias;
 do
   ${FLATPAK} $cmd --help > help_out
   head -2 help_out > help_out2

tests/test-completion.sh

@@ -34,6 +34,7 @@ install_repo
 
 ${FLATPAK} complete "flatpak a" 9 "a" | sort > complete_out
 (diff -u complete_out - || exit 1) <<EOF
+alias 
 EOF
 
 ok "complete a commands"
@@ -167,7 +168,7 @@ ok "complete NO_DIR commands"
 for cmd in history info list run update mask \
            config install make-current override remote-add repair \
            create-usb remote-delete remote-info remote-list remote-ls \
-           remote-modify search uninstall update; do
+           remote-modify search uninstall update alias; do
   len=$(awk '{ print length($0) }' <<< "flatpak $cmd --")
   ${FLATPAK} complete "flatpak $cmd --" $len "--"  > complete_out
   assert_file_has_content complete_out "^--system "

tests/update-test-matrix

@@ -34,6 +34,7 @@ TEST_MATRIX_SOURCE=(
 	'tests/test-prune.sh' \
 	'tests/test-seccomp.sh' \
 	'tests/test-repair.sh' \
+	'tests/test-alias.sh{user+system}' \
 )
 
 "${tests_srcdir}/expand-test-matrix.sh" --automake "${TEST_MATRIX_SOURCE[*]}" > "${tests_srcdir}/Makefile-test-matrix.am.inc"