import: add new minimal tool "systemd-import" for pulling down foreign containers and install them locally

This adds a simply but powerful tool for downloading container images
from the most popular container solution used today. Use it like
this:

       # systemd-import pull-dck mattdm/fedora
       # systemd-nspawn -M fedora

This will donwload the layers for "mattdm/fedora", and make them
available locally as /var/lib/container/fedora.

The tool is pretty complete, as long as it's only about pulling down
images, or updating them. Pushing or searching is not supported yet.

1 files changed, 39 insertions, 0 deletions

diff --git a/src/import/import-dck.h b/src/import/import-dck.h
new file mode 100644
index 0000000000..cd2d27c7ee
--- /dev/null
+++ b/src/import/import-dck.h
@@ -0,0 +1,39 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2014 Lennart Poettering
+
+  systemd 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.
+
+  systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "sd-event.h"
+#include "util.h"
+
+typedef struct DckImport DckImport;
+
+typedef void (*dck_import_on_finished)(DckImport *import, int error, void *userdata);
+
+int dck_import_new(DckImport **import, sd_event *event, dck_import_on_finished on_finished, void *userdata);
+DckImport* dck_import_unref(DckImport *import);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(DckImport*, dck_import_unref);
+
+int dck_import_pull(DckImport *import, const char *name, const char *tag, const char *local, bool force_local);
+int dck_import_cancel(DckImport *import, const char *name);
+
+bool dck_name_is_valid(const char *name);
+bool dck_id_is_valid(const char *id);
+#define dck_tag_is_valid(tag) filename_is_valid(tag)