importd: add API for exporting container/VM images

Also, expose it in machinectl.

1 files changed, 319 insertions, 0 deletions

diff --git a/src/import/export.c b/src/import/export.c
new file mode 100644
index 0000000000..201c5ab356
--- /dev/null
+++ b/src/import/export.c
@@ -0,0 +1,319 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2015 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 <getopt.h>
+
+#include "sd-event.h"
+#include "event-util.h"
+#include "verbs.h"
+#include "build.h"
+#include "machine-image.h"
+#include "import-util.h"
+#include "export-tar.h"
+#include "export-raw.h"
+
+static ImportCompressType arg_compress = IMPORT_COMPRESS_UNKNOWN;
+
+static void determine_compression_from_filename(const char *p) {
+
+        if (arg_compress != IMPORT_COMPRESS_UNKNOWN)
+                return;
+
+        if (!p) {
+                arg_compress = IMPORT_COMPRESS_UNCOMPRESSED;
+                return;
+        }
+
+        if (endswith(p, ".xz"))
+                arg_compress = IMPORT_COMPRESS_XZ;
+        else if (endswith(p, ".gz"))
+                arg_compress = IMPORT_COMPRESS_GZIP;
+        else if (endswith(p, ".bz2"))
+                arg_compress = IMPORT_COMPRESS_BZIP2;
+        else
+                arg_compress = IMPORT_COMPRESS_UNCOMPRESSED;
+}
+
+static int interrupt_signal_handler(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
+        log_notice("Transfer aborted.");
+        sd_event_exit(sd_event_source_get_event(s), EINTR);
+        return 0;
+}
+
+static void on_tar_finished(TarExport *export, int error, void *userdata) {
+        sd_event *event = userdata;
+        assert(export);
+
+        if (error == 0)
+                log_info("Operation completed successfully.");
+
+        sd_event_exit(event, abs(error));
+}
+
+static int export_tar(int argc, char *argv[], void *userdata) {
+        _cleanup_(tar_export_unrefp) TarExport *export = NULL;
+        _cleanup_event_unref_ sd_event *event = NULL;
+        _cleanup_(image_unrefp) Image *image = NULL;
+        const char *path = NULL, *local = NULL;
+        _cleanup_close_ int open_fd = -1;
+        int r, fd;
+
+        if (machine_name_is_valid(argv[1])) {
+                r = image_find(argv[1], &image);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to look for machine %s: %m", argv[1]);
+                if (r == 0) {
+                        log_error("Machine image %s not found.", argv[1]);
+                        return -ENOENT;
+                }
+
+                local = image->path;
+        } else
+                local = argv[1];
+
+        if (argc >= 3)
+                path = argv[2];
+        if (isempty(path) || streq(path, "-"))
+                path = NULL;
+
+        determine_compression_from_filename(path);
+
+        if (path) {
+                open_fd = open(path, O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC|O_NOCTTY, 0666);
+                if (open_fd < 0)
+                        return log_error_errno(errno, "Failed to open tar image for export: %m");
+
+                fd = open_fd;
+
+                log_info("Exporting '%s', saving to '%s' with compression '%s'.", local, path, import_compress_type_to_string(arg_compress));
+        } else {
+                _cleanup_free_ char *pretty = NULL;
+
+                fd = STDOUT_FILENO;
+
+                (void) readlink_malloc("/proc/self/fd/1", &pretty);
+                log_info("Exporting '%s', saving to '%s' with compression '%s'.", local, strna(pretty), import_compress_type_to_string(arg_compress));
+        }
+
+        r = sd_event_default(&event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate event loop: %m");
+
+        assert_se(sigprocmask_many(SIG_BLOCK, SIGTERM, SIGINT, -1) == 0);
+        sd_event_add_signal(event, NULL, SIGTERM, interrupt_signal_handler,  NULL);
+        sd_event_add_signal(event, NULL, SIGINT, interrupt_signal_handler, NULL);
+
+        r = tar_export_new(&export, event, on_tar_finished, event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate exporter: %m");
+
+        r = tar_export_start(export, local, fd, arg_compress);
+        if (r < 0)
+                return log_error_errno(r, "Failed to export image: %m");
+
+        r = sd_event_loop(event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to run event loop: %m");
+
+        log_info("Exiting.");
+        return -r;
+}
+
+static void on_raw_finished(RawExport *export, int error, void *userdata) {
+        sd_event *event = userdata;
+        assert(export);
+
+        if (error == 0)
+                log_info("Operation completed successfully.");
+
+        sd_event_exit(event, abs(error));
+}
+
+static int export_raw(int argc, char *argv[], void *userdata) {
+        _cleanup_(raw_export_unrefp) RawExport *export = NULL;
+        _cleanup_event_unref_ sd_event *event = NULL;
+        _cleanup_(image_unrefp) Image *image = NULL;
+        const char *path = NULL, *local = NULL;
+        _cleanup_close_ int open_fd = -1;
+        int r, fd;
+
+        if (machine_name_is_valid(argv[1])) {
+                r = image_find(argv[1], &image);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to look for machine %s: %m", argv[1]);
+                if (r == 0) {
+                        log_error("Machine image %s not found.", argv[1]);
+                        return -ENOENT;
+                }
+
+                local = image->path;
+        } else
+                local = argv[1];
+
+        if (argc >= 3)
+                path = argv[2];
+        if (isempty(path) || streq(path, "-"))
+                path = NULL;
+
+        determine_compression_from_filename(path);
+
+        if (path) {
+                open_fd = open(path, O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC|O_NOCTTY, 0666);
+                if (open_fd < 0)
+                        return log_error_errno(errno, "Failed to open raw image for export: %m");
+
+                fd = open_fd;
+
+                log_info("Exporting '%s', saving to '%s' with compression '%s'.", local, path, import_compress_type_to_string(arg_compress));
+        } else {
+                _cleanup_free_ char *pretty = NULL;
+
+                fd = STDOUT_FILENO;
+
+                (void) readlink_malloc("/proc/self/fd/1", &pretty);
+                log_info("Exporting '%s', saving to '%s' with compression '%s'.", local, strna(pretty), import_compress_type_to_string(arg_compress));
+        }
+
+        r = sd_event_default(&event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate event loop: %m");
+
+        assert_se(sigprocmask_many(SIG_BLOCK, SIGTERM, SIGINT, -1) == 0);
+        sd_event_add_signal(event, NULL, SIGTERM, interrupt_signal_handler,  NULL);
+        sd_event_add_signal(event, NULL, SIGINT, interrupt_signal_handler, NULL);
+
+        r = raw_export_new(&export, event, on_raw_finished, event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate exporter: %m");
+
+        r = raw_export_start(export, local, fd, arg_compress);
+        if (r < 0)
+                return log_error_errno(r, "Failed to export image: %m");
+
+        r = sd_event_loop(event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to run event loop: %m");
+
+        log_info("Exiting.");
+        return -r;
+}
+
+static int help(int argc, char *argv[], void *userdata) {
+
+        printf("%s [OPTIONS...] {COMMAND} ...\n\n"
+               "Export container or virtual machine images.\n\n"
+               "  -h --help                    Show this help\n"
+               "     --version                 Show package version\n"
+               "     --format=FORMAT           Select format\n\n"
+               "Commands:\n"
+               "  tar NAME [FILE]              Export a TAR image\n"
+               "  raw NAME [FILE]              Export a RAW image\n",
+               program_invocation_short_name);
+
+        return 0;
+}
+
+static int parse_argv(int argc, char *argv[]) {
+
+        enum {
+                ARG_VERSION = 0x100,
+                ARG_FORMAT,
+        };
+
+        static const struct option options[] = {
+                { "help",    no_argument,       NULL, 'h'         },
+                { "version", no_argument,       NULL, ARG_VERSION },
+                { "format",  required_argument, NULL, ARG_FORMAT  },
+                {}
+        };
+
+        int c;
+
+        assert(argc >= 0);
+        assert(argv);
+
+        while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
+
+                switch (c) {
+
+                case 'h':
+                        return help(0, NULL, NULL);
+
+                case ARG_VERSION:
+                        puts(PACKAGE_STRING);
+                        puts(SYSTEMD_FEATURES);
+                        return 0;
+
+                case ARG_FORMAT:
+                        if (streq(optarg, "uncompressed"))
+                                arg_compress = IMPORT_COMPRESS_UNCOMPRESSED;
+                        else if (streq(optarg, "xz"))
+                                arg_compress = IMPORT_COMPRESS_XZ;
+                        else if (streq(optarg, "gzip"))
+                                arg_compress = IMPORT_COMPRESS_GZIP;
+                        else if (streq(optarg, "bzip2"))
+                                arg_compress = IMPORT_COMPRESS_BZIP2;
+                        else {
+                                log_error("Unknown format: %s", optarg);
+                                return -EINVAL;
+                        }
+                        break;
+
+                case '?':
+                        return -EINVAL;
+
+                default:
+                        assert_not_reached("Unhandled option");
+                }
+
+        return 1;
+}
+
+static int export_main(int argc, char *argv[]) {
+
+        static const Verb verbs[] = {
+                { "help", VERB_ANY, VERB_ANY, 0, help       },
+                { "tar",  2,        3,        0, export_tar },
+                { "raw",  2,        3,        0, export_raw },
+                {}
+        };
+
+        return dispatch_verb(argc, argv, verbs, NULL);
+}
+
+int main(int argc, char *argv[]) {
+        int r;
+
+        setlocale(LC_ALL, "");
+        log_parse_environment();
+        log_open();
+
+        r = parse_argv(argc, argv);
+        if (r <= 0)
+                goto finish;
+
+        ignore_signals(SIGPIPE, -1);
+
+        r = export_main(argc, argv);
+
+finish:
+        return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
+}