import: add support for pulling raw tar balls as containers

Ubuntu provides their cloud images optionally as tarball, hence also
support downloading those.

1 files changed, 296 insertions, 0 deletions

diff --git a/src/import/import-tar.c b/src/import/import-tar.c
new file mode 100644
index 000000000..43227f61f
--- /dev/null
+++ b/src/import/import-tar.c
@@ -0,0 +1,296 @@
+/*-*- 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 <sys/prctl.h>
+#include <curl/curl.h>
+
+#include "hashmap.h"
+#include "utf8.h"
+#include "strv.h"
+#include "copy.h"
+#include "btrfs-util.h"
+#include "util.h"
+#include "macro.h"
+#include "mkdir.h"
+#include "curl-util.h"
+#include "import-job.h"
+#include "import-util.h"
+#include "import-tar.h"
+
+struct TarImport {
+        sd_event *event;
+        CurlGlue *glue;
+
+        char *image_root;
+
+        ImportJob *tar_job;
+
+        TarImportFinished on_finished;
+        void *userdata;
+
+        bool finished;
+
+        char *local;
+        bool force_local;
+
+        pid_t tar_pid;
+
+        char *temp_path;
+        char *final_path;
+};
+
+TarImport* tar_import_unref(TarImport *i) {
+        if (!i)
+                return NULL;
+
+        if (i->tar_pid > 0) {
+                kill(i->tar_pid, SIGKILL);
+                wait_for_terminate(i->tar_pid, NULL);
+        }
+
+        import_job_unref(i->tar_job);
+
+        curl_glue_unref(i->glue);
+        sd_event_unref(i->event);
+
+        if (i->temp_path) {
+                (void) btrfs_subvol_remove(i->temp_path);
+                (void) rm_rf_dangerous(i->temp_path, false, true, false);
+        }
+
+        free(i->final_path);
+        free(i->image_root);
+        free(i->local);
+
+        free(i);
+
+        return NULL;
+}
+
+int tar_import_new(TarImport **ret, sd_event *event, const char *image_root, TarImportFinished on_finished, void *userdata) {
+        _cleanup_(tar_import_unrefp) TarImport *i = NULL;
+        int r;
+
+        assert(ret);
+        assert(event);
+
+        i = new0(TarImport, 1);
+        if (!i)
+                return -ENOMEM;
+
+        i->on_finished = on_finished;
+        i->userdata = userdata;
+
+        i->image_root = strdup(image_root ?: "/var/lib/machines");
+        if (!i->image_root)
+                return -ENOMEM;
+
+        if (event)
+                i->event = sd_event_ref(event);
+        else {
+                r = sd_event_default(&i->event);
+                if (r < 0)
+                        return r;
+        }
+
+        r = curl_glue_new(&i->glue, i->event);
+        if (r < 0)
+                return r;
+
+        i->glue->on_finished = import_job_curl_on_finished;
+        i->glue->userdata = i;
+
+        *ret = i;
+        i = NULL;
+
+        return 0;
+}
+
+static void tar_import_job_on_finished(ImportJob *j) {
+        TarImport *i;
+        int r;
+
+        assert(j);
+        assert(j->userdata);
+
+        i = j->userdata;
+
+        if (j->error != 0) {
+                r = j->error;
+                goto finish;
+        }
+
+        /* This is invoked if either the download completed
+         * successfully, or the download was skipped because we
+         * already have the etag. */
+
+        j->disk_fd = safe_close(j->disk_fd);
+
+        if (i->tar_pid > 0) {
+                r = wait_for_terminate_and_warn("tar", i->tar_pid, true);
+                i->tar_pid = 0;
+                if (r < 0)
+                        goto finish;
+        }
+
+        if (i->temp_path) {
+                r = import_make_read_only(i->temp_path);
+                if (r < 0)
+                        goto finish;
+
+                if (rename(i->temp_path, i->final_path) < 0) {
+                        r = log_error_errno(errno, "Failed to rename to final image name: %m");
+                        goto finish;
+                }
+        }
+
+        if (i->local) {
+                if (!i->final_path) {
+                        r = import_make_path(j->url, j->etag, i->image_root, ".tar-", NULL, &i->final_path);
+                        if (r < 0)
+                                goto finish;
+                }
+
+                r = import_make_local_copy(i->final_path, i->image_root, i->local, i->force_local);
+                if (r < 0)
+                        goto finish;
+        }
+
+        r = 0;
+
+finish:
+        i->finished = true;
+
+        if (i->on_finished)
+                i->on_finished(i, r, i->userdata);
+        else
+                sd_event_exit(i->event, r);
+}
+
+static int tar_import_job_on_open_disk(ImportJob *j) {
+        _cleanup_close_pair_ int pipefd[2] = { -1 , -1 };
+        TarImport *i;
+        int r;
+
+        assert(j);
+        assert(j->userdata);
+
+        i = j->userdata;
+
+        r = import_make_path(j->url, j->etag, i->image_root, ".tar-", NULL, &i->final_path);
+        if (r < 0)
+                return log_oom();
+
+        r = tempfn_random(i->final_path, &i->temp_path);
+        if (r < 0)
+                return log_oom();
+
+        mkdir_parents_label(i->temp_path, 0700);
+
+        r = btrfs_subvol_make(i->temp_path);
+        if (r == -ENOTTY) {
+                if (mkdir(i->temp_path, 0755) < 0)
+                        return log_error_errno(errno, "Failed to create directory %s: %m", i->temp_path);
+        } else if (r < 0)
+                return log_error_errno(errno, "Failed to create subvolume %s: %m", i->temp_path);
+
+        if (pipe2(pipefd, O_CLOEXEC) < 0)
+                return log_error_errno(errno, "Failed to create pipe for tar: %m");
+
+        i->tar_pid = fork();
+        if (i->tar_pid < 0)
+                return log_error_errno(errno, "Failed to fork off tar: %m");
+        if (i->tar_pid == 0) {
+                int null_fd;
+
+                reset_all_signal_handlers();
+                reset_signal_mask();
+                assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
+
+                pipefd[1] = safe_close(pipefd[1]);
+
+                if (dup2(pipefd[0], STDIN_FILENO) != STDIN_FILENO) {
+                        log_error_errno(errno, "Failed to dup2() fd: %m");
+                        _exit(EXIT_FAILURE);
+                }
+
+                if (pipefd[0] != STDIN_FILENO)
+                        safe_close(pipefd[0]);
+
+                null_fd = open("/dev/null", O_WRONLY|O_NOCTTY);
+                if (null_fd < 0) {
+                        log_error_errno(errno, "Failed to open /dev/null: %m");
+                        _exit(EXIT_FAILURE);
+                }
+
+                if (dup2(null_fd, STDOUT_FILENO) != STDOUT_FILENO) {
+                        log_error_errno(errno, "Failed to dup2() fd: %m");
+                        _exit(EXIT_FAILURE);
+                }
+
+                if (null_fd != STDOUT_FILENO)
+                        safe_close(null_fd);
+
+                execlp("tar", "tar", "--numeric-owner", "-C", i->temp_path, "-px", NULL);
+                _exit(EXIT_FAILURE);
+        }
+
+        pipefd[0] = safe_close(pipefd[0]);
+
+        j->disk_fd = pipefd[1];
+        pipefd[1] = -1;
+
+        return 0;
+}
+
+int tar_import_pull(TarImport *i, const char *url, const char *local, bool force_local) {
+        int r;
+
+        assert(i);
+
+        if (i->tar_job)
+                return -EBUSY;
+
+        if (!http_url_is_valid(url))
+                return -EINVAL;
+
+        if (local && !machine_name_is_valid(local))
+                return -EINVAL;
+
+        r = free_and_strdup(&i->local, local);
+        if (r < 0)
+                return r;
+
+        i->force_local = force_local;
+
+        r = import_job_new(&i->tar_job, url, i->glue, i);
+        if (r < 0)
+                return r;
+
+        i->tar_job->on_finished = tar_import_job_on_finished;
+        i->tar_job->on_open_disk = tar_import_job_on_open_disk;
+
+        r = import_find_old_etags(url, i->image_root, DT_DIR, ".tar-", NULL, &i->tar_job->old_etags);
+        if (r < 0)
+                return r;
+
+        return import_job_begin(i->tar_job);
+}