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, 56 insertions, 0 deletions

diff --git a/src/import/curl-util.h b/src/import/curl-util.h
new file mode 100644
index 0000000000..5a7550deb9
--- /dev/null
+++ b/src/import/curl-util.h
@@ -0,0 +1,56 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  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 <sys/types.h>
+#include <curl/curl.h>
+
+#include "hashmap.h"
+#include "sd-event.h"
+
+typedef struct CurlGlue CurlGlue;
+
+struct CurlGlue {
+        sd_event *event;
+        CURLM *curl;
+        sd_event_source *timer;
+        Hashmap *ios;
+        Hashmap *translate_fds;
+
+        void (*on_finished)(CurlGlue *g, CURL *curl, CURLcode code);
+        void *userdata;
+};
+
+int curl_glue_new(CurlGlue **glue, sd_event *event);
+CurlGlue* curl_glue_unref(CurlGlue *glue);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(CurlGlue*, curl_glue_unref);
+
+int curl_glue_make(CURL **ret, const char *url, void *userdata);
+int curl_glue_add(CurlGlue *g, CURL *c);
+void curl_glue_remove_and_free(CurlGlue *g, CURL *c);
+
+struct curl_slist *curl_slist_new(const char *first, ...) _sentinel_;
+int curl_header_strdup(const void *contents, size_t sz, const char *field, char **value);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(CURL*, curl_easy_cleanup);
+DEFINE_TRIVIAL_CLEANUP_FUNC(struct curl_slist*, curl_slist_free_all);