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authorMichal Sekletar <msekleta@redhat.com>2016-04-08 13:22:54 +0200
committerMichal Sekletar <msekleta@redhat.com>2016-04-11 16:43:16 +0200
commite01ff70a77e781734e1e73a2238af2e9bf7967a8 (patch)
tree8235651af0b93081b1db89026bdbc061540263ee /src/nspawn/nspawn.c
parent710a8858a930a13da8dabbba61d64eb8f420b448 (diff)
nspawn: always setup machine id
We check /etc/machine-id of the container and if it is already populated we use value from there, possibly ignoring value of --uuid option from the command line. When dealing with R/O image we setup transient machine id. Once we determined machine id of the container, we use this value for registration with systemd-machined and we also export it via container_uuid environment variable. As registration with systemd-machined is done by the main nspawn process we communicate container machine id established by setup_machine_id from outer child to the main process by unix domain socket. Similarly to PID of inner child.
Diffstat (limited to 'src/nspawn/nspawn.c')
-rw-r--r--src/nspawn/nspawn.c108
1 files changed, 81 insertions, 27 deletions
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index eb89916b7e..1197802779 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -64,6 +64,7 @@
#include "hostname-util.h"
#include "log.h"
#include "loopback-setup.h"
+#include "machine-id-setup.h"
#include "machine-image.h"
#include "macro.h"
#include "missing.h"
@@ -1375,11 +1376,11 @@ static int setup_hostname(void) {
}
static int setup_journal(const char *directory) {
- sd_id128_t machine_id, this_id;
+ sd_id128_t this_id;
_cleanup_free_ char *b = NULL, *d = NULL;
- const char *etc_machine_id, *p, *q;
+ const char *p, *q;
bool try;
- char *id;
+ char id[33];
int r;
/* Don't link journals in ephemeral mode */
@@ -1391,28 +1392,11 @@ static int setup_journal(const char *directory) {
try = arg_link_journal_try || arg_link_journal == LINK_AUTO;
- etc_machine_id = prefix_roota(directory, "/etc/machine-id");
-
- r = read_one_line_file(etc_machine_id, &b);
- if (r == -ENOENT && try)
- return 0;
- else if (r < 0)
- return log_error_errno(r, "Failed to read machine ID from %s: %m", etc_machine_id);
-
- id = strstrip(b);
- if (isempty(id) && try)
- return 0;
-
- /* Verify validity */
- r = sd_id128_from_string(id, &machine_id);
- if (r < 0)
- return log_error_errno(r, "Failed to parse machine ID from %s: %m", etc_machine_id);
-
r = sd_id128_get_machine(&this_id);
if (r < 0)
return log_error_errno(r, "Failed to retrieve machine ID: %m");
- if (sd_id128_equal(machine_id, this_id)) {
+ if (sd_id128_equal(arg_uuid, this_id)) {
log_full(try ? LOG_WARNING : LOG_ERR,
"Host and machine ids are equal (%s): refusing to link journals", id);
if (try)
@@ -1432,6 +1416,8 @@ static int setup_journal(const char *directory) {
if (r < 0)
return log_error_errno(r, "Failed to create /var/log/journal: %m");
+ (void) sd_id128_to_string(arg_uuid, id);
+
p = strjoina("/var/log/journal/", id);
q = prefix_roota(directory, p);
@@ -2201,6 +2187,38 @@ static int mount_device(const char *what, const char *where, const char *directo
#endif
}
+static int setup_machine_id(const char *directory) {
+ int r;
+ const char *etc_machine_id, *t;
+ _cleanup_free_ char *s = NULL;
+
+ etc_machine_id = prefix_roota(directory, "/etc/machine-id");
+
+ r = read_one_line_file(etc_machine_id, &s);
+ if (r < 0)
+ return log_error_errno(r, "Failed to read machine ID from %s: %m", etc_machine_id);
+
+ t = strstrip(s);
+
+ if (!isempty(t)) {
+ r = sd_id128_from_string(t, &arg_uuid);
+ if (r < 0)
+ return log_error_errno(r, "Failed to parse machine ID from %s: %m", etc_machine_id);
+ } else {
+ if (sd_id128_is_null(arg_uuid)) {
+ r = sd_id128_randomize(&arg_uuid);
+ if (r < 0)
+ return log_error_errno(r, "Failed to generate random machine ID: %m");
+ }
+ }
+
+ r = machine_id_setup(directory, arg_uuid);
+ if (r < 0)
+ return log_error_errno(r, "Failed to setup machine ID: %m");
+
+ return 0;
+}
+
static int mount_devices(
const char *where,
const char *root_device, bool root_device_rw,
@@ -2458,6 +2476,7 @@ static int inner_child(
FDSet *fds) {
_cleanup_free_ char *home = NULL;
+ char as_uuid[37];
unsigned n_env = 1;
const char *envp[] = {
"PATH=" DEFAULT_PATH_SPLIT_USR,
@@ -2575,12 +2594,10 @@ static int inner_child(
(asprintf((char**)(envp + n_env++), "LOGNAME=%s", arg_user ? arg_user : "root") < 0))
return log_oom();
- if (!sd_id128_equal(arg_uuid, SD_ID128_NULL)) {
- char as_uuid[37];
+ assert(!sd_id128_equal(arg_uuid, SD_ID128_NULL));
- if (asprintf((char**)(envp + n_env++), "container_uuid=%s", id128_format_as_uuid(arg_uuid, as_uuid)) < 0)
- return log_oom();
- }
+ if (asprintf((char**)(envp + n_env++), "container_uuid=%s", id128_format_as_uuid(arg_uuid, as_uuid)) < 0)
+ return log_oom();
if (fdset_size(fds) > 0) {
r = fdset_cloexec(fds, false);
@@ -2669,6 +2686,7 @@ static int outer_child(
bool interactive,
bool secondary,
int pid_socket,
+ int uuid_socket,
int kmsg_socket,
int rtnl_socket,
int uid_shift_socket,
@@ -2682,6 +2700,7 @@ static int outer_child(
assert(directory);
assert(console);
assert(pid_socket >= 0);
+ assert(uuid_socket >= 0);
assert(kmsg_socket >= 0);
cg_unified_flush();
@@ -2796,6 +2815,10 @@ static int outer_child(
if (r < 0)
return r;
+ r = setup_machine_id(directory);
+ if (r < 0)
+ return r;
+
r = setup_journal(directory);
if (r < 0)
return r;
@@ -2821,6 +2844,7 @@ static int outer_child(
return log_error_errno(errno, "Failed to fork inner child: %m");
if (pid == 0) {
pid_socket = safe_close(pid_socket);
+ uuid_socket = safe_close(uuid_socket);
uid_shift_socket = safe_close(uid_shift_socket);
/* The inner child has all namespaces that are
@@ -2842,7 +2866,16 @@ static int outer_child(
return -EIO;
}
+ l = send(uuid_socket, &arg_uuid, sizeof(arg_uuid), MSG_NOSIGNAL);
+ if (l < 0)
+ return log_error_errno(errno, "Failed to send machine ID: %m");
+ if (l != sizeof(arg_uuid)) {
+ log_error("Short write while sending machine ID.");
+ return -EIO;
+ }
+
pid_socket = safe_close(pid_socket);
+ uuid_socket = safe_close(uuid_socket);
kmsg_socket = safe_close(kmsg_socket);
rtnl_socket = safe_close(rtnl_socket);
@@ -3318,7 +3351,8 @@ int main(int argc, char *argv[]) {
}
for (;;) {
- _cleanup_close_pair_ int kmsg_socket_pair[2] = { -1, -1 }, rtnl_socket_pair[2] = { -1, -1 }, pid_socket_pair[2] = { -1, -1 }, uid_shift_socket_pair[2] = { -1, -1 };
+ _cleanup_close_pair_ int kmsg_socket_pair[2] = { -1, -1 }, rtnl_socket_pair[2] = { -1, -1 },
+ pid_socket_pair[2] = { -1, -1 }, uuid_socket_pair[2] = { -1, -1 }, uid_shift_socket_pair[2] = { -1, -1 };
ContainerStatus container_status;
_cleanup_(barrier_destroy) Barrier barrier = BARRIER_NULL;
static const struct sigaction sa = {
@@ -3353,6 +3387,11 @@ int main(int argc, char *argv[]) {
goto finish;
}
+ if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, uuid_socket_pair) < 0) {
+ r = log_error_errno(errno, "Failed to create id socket pair: %m");
+ goto finish;
+ }
+
if (arg_userns)
if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, uid_shift_socket_pair) < 0) {
r = log_error_errno(errno, "Failed to create uid shift socket pair: %m");
@@ -3393,6 +3432,7 @@ int main(int argc, char *argv[]) {
kmsg_socket_pair[0] = safe_close(kmsg_socket_pair[0]);
rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]);
pid_socket_pair[0] = safe_close(pid_socket_pair[0]);
+ uuid_socket_pair[0] = safe_close(uuid_socket_pair[0]);
uid_shift_socket_pair[0] = safe_close(uid_shift_socket_pair[0]);
(void) reset_all_signal_handlers();
@@ -3407,6 +3447,7 @@ int main(int argc, char *argv[]) {
interactive,
secondary,
pid_socket_pair[1],
+ uuid_socket_pair[1],
kmsg_socket_pair[1],
rtnl_socket_pair[1],
uid_shift_socket_pair[1],
@@ -3424,6 +3465,7 @@ int main(int argc, char *argv[]) {
kmsg_socket_pair[1] = safe_close(kmsg_socket_pair[1]);
rtnl_socket_pair[1] = safe_close(rtnl_socket_pair[1]);
pid_socket_pair[1] = safe_close(pid_socket_pair[1]);
+ uuid_socket_pair[1] = safe_close(uuid_socket_pair[1]);
uid_shift_socket_pair[1] = safe_close(uid_shift_socket_pair[1]);
/* Wait for the outer child. */
@@ -3448,6 +3490,18 @@ int main(int argc, char *argv[]) {
goto finish;
}
+ /* We also retrieve container UUID in case it was generated by outer child */
+ l = recv(uuid_socket_pair[0], &arg_uuid, sizeof(arg_uuid), 0);
+ if (l < 0) {
+ r = log_error_errno(errno, "Failed to read container machine ID: %m");
+ goto finish;
+ }
+ if (l != sizeof(arg_uuid)) {
+ log_error("Short read while reading container machined ID.");
+ r = EIO;
+ goto finish;
+ }
+
log_debug("Init process invoked as PID " PID_FMT, pid);
if (arg_userns) {