find-remotes: Add a find-remotes built-in command

This is a wrapper around the new ostree_repo_find_remotes() method; it
tries to find available remotes which can serve updates for the
user-provided refs.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Closes: #924
Approved by: cgwalters

Makefile-ostree.am

@@ -53,6 +53,10 @@ ostree_SOURCES = src/ostree/main.c \
 	src/ostree/parse-datetime.c \
 	$(NULL)
 
+if ENABLE_EXPERIMENTAL_API
+ostree_SOURCES += src/ostree/ot-builtin-find-remotes.c
+endif
+
 # Admin subcommand
 ostree_SOURCES += \
 	src/ostree/ot-admin-builtin-init-fs.c \

src/ostree/main.c

@@ -41,6 +41,9 @@ static OstreeCommand commands[] = {
   { "config", ostree_builtin_config },
   { "diff", ostree_builtin_diff },
   { "export", ostree_builtin_export },
+#ifdef OSTREE_ENABLE_EXPERIMENTAL_API
+  { "find-remotes", ostree_builtin_find_remotes },
+#endif
   { "fsck", ostree_builtin_fsck },
   { "gpg-sign", ostree_builtin_gpg_sign },
   { "init", ostree_builtin_init },

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

@@ -0,0 +1,255 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright © 2017 Endless Mobile, 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.
+ *
+ * Authors:
+ *  - Philip Withnall <withnall@endlessm.com>
+ */
+
+#include "config.h"
+
+#include "ot-main.h"
+#include "ot-builtins.h"
+#include "ostree.h"
+#include "otutil.h"
+
+#include "ostree-remote-private.h"
+
+static gchar *opt_cache_dir = NULL;
+static gboolean opt_disable_fsync = FALSE;
+
+static GOptionEntry options[] =
+  {
+    { "cache-dir", 0, 0, G_OPTION_ARG_FILENAME, &opt_cache_dir, "Use custom cache dir", NULL },
+    { "disable-fsync", 0, 0, G_OPTION_ARG_NONE, &opt_disable_fsync, "Do not invoke fsync()", NULL },
+    { NULL }
+  };
+
+static gchar *
+uint64_secs_to_iso8601 (guint64 secs)
+{
+  g_autoptr(GDateTime) dt = g_date_time_new_from_unix_utc (secs);
+
+  if (dt != NULL)
+    return g_date_time_format (dt, "%FT%TZ");
+  else
+    return g_strdup ("invalid");
+}
+
+static gchar *
+format_ref_to_checksum (GHashTable  *ref_to_checksum  /* (element-type OstreeCollectionRef utf8) */,
+                        const gchar *line_prefix)
+{
+  GHashTableIter iter;
+  const OstreeCollectionRef *ref;
+  const gchar *checksum;
+  g_autoptr(GString) out = NULL;
+
+  g_hash_table_iter_init (&iter, ref_to_checksum);
+  out = g_string_new ("");
+
+  while (g_hash_table_iter_next (&iter, (gpointer *) &ref, (gpointer *) &checksum))
+    g_string_append_printf (out, "%s - (%s, %s) = %s\n",
+                            line_prefix, ref->collection_id, ref->ref_name,
+                            (checksum != NULL) ? checksum : "(not found)");
+
+  return g_string_free (g_steal_pointer (&out), FALSE);
+}
+
+static gchar *
+remote_get_uri (OstreeRemote *remote)
+{
+  g_autoptr(GError) error = NULL;
+  g_autofree gchar *uri = NULL;
+
+  uri = g_key_file_get_string (remote->options, remote->group, "url", &error);
+  g_assert_no_error (error);
+
+  return g_steal_pointer (&uri);
+}
+
+/* Add each key from @keys_input to @set iff its value is non-%NULL. */
+static void
+add_keys_to_set_if_non_null (GHashTable *set,
+                             GHashTable *keys_input)
+{
+  GHashTableIter iter;
+  gpointer key, value;
+
+  g_hash_table_iter_init (&iter, keys_input);
+
+  while (g_hash_table_iter_next (&iter, &key, &value))
+    if (value != NULL)
+      g_hash_table_add (set, key);
+}
+
+static void
+get_result_cb (GObject      *obj,
+               GAsyncResult *result,
+               gpointer      user_data)
+{
+  GAsyncResult **result_out = user_data;
+  *result_out = g_object_ref (result);
+}
+
+static void
+collection_ref_free0 (OstreeCollectionRef *ref)
+{
+  if (ref == NULL)
+    return;
+  ostree_collection_ref_free (ref);
+}
+
+/* TODO: Add a man page. */
+gboolean
+ostree_builtin_find_remotes (int            argc,
+                             char         **argv,
+                             GCancellable  *cancellable,
+                             GError       **error)
+{
+  g_autoptr(GOptionContext) context = NULL;
+  glnx_unref_object OstreeRepo *repo = NULL;
+  g_autoptr(GPtrArray) refs = NULL;  /* (element-type OstreeCollectionRef) */
+  glnx_unref_object OstreeAsyncProgress *progress = NULL;
+  gsize i;
+  g_autoptr(GAsyncResult) find_result = NULL;
+  g_auto(OstreeRepoFinderResultv) results = NULL;
+  g_auto(GLnxConsoleRef) console = { 0, };
+  g_autoptr(GHashTable) refs_found = NULL;  /* set (element-type OstreeCollectionRef) */
+
+  context = g_option_context_new ("COLLECTION-ID REF [COLLECTION-ID REF...] - Find remotes to serve the given refs");
+
+  /* Parse options. */
+  if (!ostree_option_context_parse (context, options, &argc, &argv, OSTREE_BUILTIN_FLAG_NONE, &repo, cancellable, error))
+    return FALSE;
+
+  if (!ostree_ensure_repo_writable (repo, error))
+    return FALSE;
+
+  if (argc < 3)
+    {
+      ot_util_usage_error (context, "At least one COLLECTION-ID REF pair must be specified", error);
+      return FALSE;
+    }
+
+  if (argc % 2 == 0)
+    {
+      ot_util_usage_error (context, "Only complete COLLECTION-ID REF pairs may be specified", error);
+      return FALSE;
+    }
+
+  if (opt_disable_fsync)
+    ostree_repo_set_disable_fsync (repo, TRUE);
+
+  if (opt_cache_dir &&
+      !ostree_repo_set_cache_dir (repo, AT_FDCWD, opt_cache_dir, cancellable, error))
+    return FALSE;
+
+  /* Read in the refs to search for remotes for. */
+  refs = g_ptr_array_new_full (argc, (GDestroyNotify) collection_ref_free0);
+
+  for (i = 1; i < argc; i += 2)
+    {
+      if (!ostree_validate_collection_id (argv[i], error) ||
+          !ostree_validate_rev (argv[i + 1], error))
+        return FALSE;
+
+      g_ptr_array_add (refs, ostree_collection_ref_new (argv[i], argv[i + 1]));
+    }
+
+  g_ptr_array_add (refs, 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 */,
+                                  progress, cancellable,
+                                  get_result_cb, &find_result);
+
+  while (find_result == NULL)
+    g_main_context_iteration (NULL, TRUE);
+
+  results = ostree_repo_find_remotes_finish (repo, find_result, error);
+
+  if (results == NULL)
+    return FALSE;
+
+  if (progress)
+    ostree_async_progress_finish (progress);
+
+  /* Print results and work out which refs were not found. */
+  refs_found = g_hash_table_new_full (ostree_collection_ref_hash,
+                                      ostree_collection_ref_equal, NULL, NULL);
+
+  for (i = 0; results[i] != NULL; i++)
+    {
+      g_autofree gchar *uri = NULL;
+      g_autofree gchar *refs_string = NULL;
+      g_autofree gchar *last_modified_string = NULL;
+
+      uri = remote_get_uri (results[i]->remote);
+      refs_string = format_ref_to_checksum (results[i]->ref_to_checksum, "   ");
+      add_keys_to_set_if_non_null (refs_found, results[i]->ref_to_checksum);
+
+      if (results[i]->summary_last_modified > 0)
+        last_modified_string = uint64_secs_to_iso8601 (results[i]->summary_last_modified);
+      else
+        last_modified_string = g_strdup ("unknown");
+
+      g_print ("Result %" G_GSIZE_FORMAT ": %s\n"
+               " - Finder: %s\n"
+               " - Keyring: %s\n"
+               " - Priority: %d\n"
+               " - Summary last modified: %s\n"
+               " - Refs:\n"
+               "%s\n",
+               i, uri, G_OBJECT_TYPE_NAME (results[i]->finder), results[i]->remote->keyring,
+               results[i]->priority, last_modified_string, refs_string);
+    }
+
+  if (results[0] == NULL)
+    {
+      g_print ("No results.\n");
+      return TRUE;
+    }
+
+  g_print ("%u/%u refs were found.\n", g_hash_table_size (refs_found), refs->len - 1);
+
+  /* Print out the refs which weren’t found. */
+  if (g_hash_table_size (refs_found) != refs->len - 1  /* NULL terminator */)
+    {
+      g_print ("Refs not found in any remote:\n");
+
+      for (i = 0; i < refs->len && refs->pdata[i] != NULL; i++)
+        {
+          const OstreeCollectionRef *ref = g_ptr_array_index (refs, i);
+          if (!g_hash_table_contains (refs_found, ref))
+            g_print (" - (%s, %s)\n", ref->collection_id, ref->ref_name);
+        }
+    }
+
+  return TRUE;
+}

src/ostree/ot-builtins.h

@@ -22,6 +22,8 @@
 
 #pragma once
 
+#include "config.h"
+
 #include "ostree.h"
 
 G_BEGIN_DECLS
@@ -36,6 +38,9 @@ BUILTINPROTO(checksum);
 BUILTINPROTO(commit);
 BUILTINPROTO(diff);
 BUILTINPROTO(export);
+#ifdef OSTREE_ENABLE_EXPERIMENTAL_API
+BUILTINPROTO(find_remotes);
+#endif
 BUILTINPROTO(gpg_sign);
 BUILTINPROTO(init);
 BUILTINPROTO(log);