find-remotes: Add --finders option

It can be helpful to be able to choose which OstreeRepoFinder instances
to use when using the find-remotes command. For example, if the tests
need to run in an environment that can't have an Avahi daemon, this
allows you to disable the Avahi (LAN) finder. This commit adds the
--finders option for this purpose.

Closes: #1407
Approved by: cgwalters

src/ostree/ot-builtin-find-remotes.c

@@ -30,12 +30,14 @@
 #include "ostree-remote-private.h"
 
 static gchar *opt_cache_dir = NULL;
+static gchar *opt_finders = NULL;
 static gboolean opt_disable_fsync = FALSE;
 static gboolean opt_pull = FALSE;
 
 static GOptionEntry options[] =
   {
     { "cache-dir", 0, 0, G_OPTION_ARG_FILENAME, &opt_cache_dir, "Use custom cache dir", NULL },
+    { "finders", 0, 0, G_OPTION_ARG_STRING, &opt_finders, "Use the specified comma separated list of finders (e.g. config,lan,mount)", "FINDERS" },
     { "disable-fsync", 0, 0, G_OPTION_ARG_NONE, &opt_disable_fsync, "Do not invoke fsync()", NULL },
     { "pull", 0, 0, G_OPTION_ARG_NONE, &opt_pull, "Pull the updates after finding them", NULL },
     { NULL }
@@ -116,6 +118,52 @@ collection_ref_free0 (OstreeCollectionRef *ref)
   ostree_collection_ref_free (ref);
 }
 
+static gboolean
+validate_finders_list (char           **finders,
+                       GOptionContext  *context,
+                       GError         **error)
+{
+  typedef struct {
+    gchar *finder_name;
+    gboolean already_used;
+  } Finder;
+  Finder valid_finders[] = {
+    {.finder_name = "config", .already_used = FALSE},
+    {.finder_name = "lan", .already_used = FALSE},
+    {.finder_name = "mount", .already_used = FALSE}
+  };
+
+  if (finders == NULL || *finders == NULL)
+    {
+      ot_util_usage_error (context, "List of finders in --finders option must not be empty", error);
+      return FALSE;
+    }
+
+  for (char **iter = finders; iter && *iter; iter++)
+    {
+      gboolean is_valid_finder = FALSE;
+      for (int i = 0; i < 3; i++)
+        {
+          if (valid_finders[i].already_used == TRUE)
+            continue;
+          if (g_strcmp0 (*iter, valid_finders[i].finder_name) == 0)
+            {
+              is_valid_finder = TRUE;
+              valid_finders[i].already_used = TRUE;
+            }
+        }
+      if (!is_valid_finder)
+        {
+          g_autofree gchar *error_msg = NULL;
+          error_msg = g_strdup_printf ("Unknown or duplicate finder type given in --finders option: ‘%s’", *iter);
+          ot_util_usage_error (context, error_msg, error);
+          return FALSE;
+        }
+    }
+
+  return TRUE;
+}
+
 /* TODO: Add a man page. */
 gboolean
 ostree_builtin_find_remotes (int            argc,
@@ -127,12 +175,17 @@ ostree_builtin_find_remotes (int            argc,
   g_autoptr(GOptionContext) context = NULL;
   g_autoptr(OstreeRepo) repo = NULL;
   g_autoptr(GPtrArray) refs = NULL;  /* (element-type OstreeCollectionRef) */
+  g_autoptr(GPtrArray) finders = NULL;  /* (element-type OstreeRepoFinder) */
+  g_autoptr(OstreeRepoFinder) finder_config = NULL;
+  g_autoptr(OstreeRepoFinder) finder_mount = NULL;
+  g_autoptr(OstreeRepoFinder) finder_avahi = NULL;
   g_autoptr(OstreeAsyncProgress) progress = NULL;
   gsize i;
   g_autoptr(GAsyncResult) find_result = NULL, pull_result = NULL;
   g_auto(OstreeRepoFinderResultv) results = NULL;
   g_auto(GLnxConsoleRef) console = { 0, };
   g_autoptr(GHashTable) refs_found = NULL;  /* set (element-type OstreeCollectionRef) */
+  g_auto(GStrv) finders_strings = NULL;
 
   context = g_option_context_new ("COLLECTION-ID REF [COLLECTION-ID REF...]");
 
@@ -176,18 +229,65 @@ ostree_builtin_find_remotes (int            argc,
 
   g_ptr_array_add (refs, NULL);
 
+  /* Build the array of OstreeRepoFinder instances */
+  if (opt_finders != NULL)
+    {
+      g_auto(GStrv) finders_strings = NULL;
+
+      finders_strings = g_strsplit (opt_finders, ",", 0);
+      if (!validate_finders_list (finders_strings, context, error))
+        return FALSE;
+
+      finders = g_ptr_array_new ();
+      for (char **iter =finders_strings; iter && *iter; iter++)
+        {
+          if (g_strcmp0 (*iter, "config") == 0)
+            {
+              finder_config = OSTREE_REPO_FINDER (ostree_repo_finder_config_new ());
+              g_ptr_array_add (finders, finder_config);
+            }
+          else if (g_strcmp0 (*iter, "mount") == 0)
+            {
+              finder_mount = OSTREE_REPO_FINDER (ostree_repo_finder_mount_new (NULL));
+              g_ptr_array_add (finders, finder_mount);
+            }
+          else if (g_strcmp0 (*iter, "lan") == 0)
+            {
+#ifdef HAVE_AVAHI
+              GMainContext *main_context = g_main_context_get_thread_default ();
+              g_autoptr(GError) local_error = NULL;
+
+              finder_avahi = OSTREE_REPO_FINDER (ostree_repo_finder_avahi_new (main_context));
+              ostree_repo_finder_avahi_start (OSTREE_REPO_FINDER_AVAHI (finder_avahi), &local_error);
+
+              if (local_error != NULL)
+                {
+                  g_warning ("Avahi finder failed; removing it: %s", local_error->message);
+                  g_clear_object (&finder_avahi);
+                }
+              else
+                g_ptr_array_add (finders, finder_avahi);
+#else
+              ot_util_usage_error (context, "LAN repo finder requested but ostree was compiled without Avahi support", error);
+              return FALSE;
+#endif  /* HAVE_AVAHI */
+            }
+          else
+            g_assert_not_reached ();
+        }
+      g_ptr_array_add (finders, NULL);
+    }
+
   /* Run the operation. */
   glnx_console_lock (&console);
 
   if (console.is_tty)
     progress = ostree_async_progress_new_and_connect (ostree_repo_pull_default_console_progress_changed, &console);
 
-  /* FIXME: Eventually some command line options for customising the finders
-   * list would be good. */
   ostree_repo_find_remotes_async (repo,
                                   (const OstreeCollectionRef * const *) refs->pdata,
                                   NULL  /* no options */,
-                                  NULL  /* default finders */,
+                                  finders != NULL ? (OstreeRepoFinder **) finders->pdata : NULL,
                                   progress, cancellable,
                                   get_result_cb, &find_result);