From 308d72dc1e2106f94ae637e2ea510e8d466d2af1 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Thu, 21 Aug 2014 17:03:15 +0200
Subject: [PATCH] core: allow informing systemd about service status changes
with RELOADING=1 and STOPPING=1 sd_notify() messages
---
man/sd_notify.xml | 93 ++++++++++++++++++++++++++++---------------
src/core/service.c | 105 +++++++++++++++++++++++++++++++++++++++++++------
src/core/service.h | 13 ++++++
src/test/test-daemon.c | 22 +++++++++--
4 files changed, 185 insertions(+), 48 deletions(-)
diff --git a/man/sd_notify.xml b/man/sd_notify.xml
index 6bf8230763..fbb882dfd2 100644
--- a/man/sd_notify.xml
+++ b/man/sd_notify.xml
@@ -46,7 +46,7 @@
<refnamediv>
<refname>sd_notify</refname>
<refname>sd_notifyf</refname>
- <refpurpose>Notify service manager about start-up completion and other daemon status changes</refpurpose>
+ <refpurpose>Notify service manager about start-up completion and other service status changes</refpurpose>
</refnamediv>
<refsynopsisdiv>
@@ -70,12 +70,12 @@
<refsect1>
<title>Description</title>
- <para><function>sd_notify()</function> shall be called
- by a daemon to notify the init system about status
- changes. It can be used to send arbitrary information,
- encoded in an environment-block-like string. Most
- importantly it can be used for start-up completion
- notification.</para>
+ <para><function>sd_notify()</function> may be called
+ by a service to notify the service manager about
+ state changes. It can be used to send arbitrary
+ information, encoded in an environment-block-like
+ string. Most importantly it can be used for start-up
+ completion notification.</para>
<para>If the <parameter>unset_environment</parameter>
parameter is non-zero, <function>sd_notify()</function>
@@ -99,58 +99,87 @@
<varlistentry>
<term>READY=1</term>
- <listitem><para>Tells the init system
- that daemon startup is finished. This
- is only used by systemd if the service
- definition file has Type=notify
- set. The passed argument is a boolean
- "1" or "0". Since there is little
+ <listitem><para>Tells the service
+ manager that service startup is
+ finished. This is only used by systemd
+ if the service definition file has
+ Type=notify set. Since there is little
value in signaling non-readiness, the
- only value daemons should send is
- "READY=1".</para></listitem>
+ only value services should send is
+ <literal>READY=1</literal>
+ (i.e. <literal>READY=0</literal> is
+ not defined).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>RELOADING=1</term>
+
+ <listitem><para>Tells the service manager
+ that the service is reloading its
+ configuration. This is useful to allow
+ the service manager to track the service's
+ internal state, and present it to the
+ user. Note that a service that sends
+ this notification must also send a
+ <literal>READY=1</literal>
+ notification when it completed
+ reloading its
+ configuration.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>STOPPING=1</term>
+
+ <listitem><para>Tells the service manager
+ that the service is beginning its
+ shutdown. This is useful to allow the
+ service manager to track the service's
+ internal state, and present it to the
+ user.</para></listitem>
</varlistentry>
<varlistentry>
<term>STATUS=...</term>
<listitem><para>Passes a single-line
- status string back to the init system
- that describes the daemon state. This
+ UTF-8 status string back to the service manager
+ that describes the service state. This
is free-form and can be used for
various purposes: general state
feedback, fsck-like programs could
pass completion percentages and
failing programs could pass a human
readable error message. Example:
- "STATUS=Completed 66% of file system
- check..."</para></listitem>
+ <literal>STATUS=Completed 66% of file
+ system
+ check...</literal></para></listitem>
</varlistentry>
<varlistentry>
<term>ERRNO=...</term>
- <listitem><para>If a daemon fails, the
+ <listitem><para>If a service fails, the
errno-style error code, formatted as
- string. Example: "ERRNO=2" for
+ string. Example: <literal>ERRNO=2</literal> for
ENOENT.</para></listitem>
</varlistentry>
<varlistentry>
<term>BUSERROR=...</term>
- <listitem><para>If a daemon fails, the
+ <listitem><para>If a service fails, the
D-Bus error-style error code. Example:
- "BUSERROR=org.freedesktop.DBus.Error.TimedOut"</para></listitem>
+ <literal>BUSERROR=org.freedesktop.DBus.Error.TimedOut</literal></para></listitem>
</varlistentry>
<varlistentry>
<term>MAINPID=...</term>
<listitem><para>The main pid of the
- daemon, in case the init system did
+ service, in case the service manager did
not fork off the process
itself. Example:
- "MAINPID=4711"</para></listitem>
+ <literal>MAINPID=4711</literal></para></listitem>
</varlistentry>
<varlistentry>
@@ -183,7 +212,7 @@
clashes.</para>
<para>Note that systemd will accept status data sent
- from a daemon only if the
+ from a service only if the
<varname>NotifyAccess=</varname> option is correctly
set in the service definition file. See
<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
@@ -222,7 +251,7 @@
<varname>$NOTIFY_SOCKET</varname> is <literal>@</literal>, the string is
understood as Linux abstract namespace socket. The
datagram is accompanied by the process credentials of
- the sending daemon, using SCM_CREDENTIALS.</para>
+ the sending service, using SCM_CREDENTIALS.</para>
</refsect1>
<refsect1>
@@ -232,7 +261,7 @@
<varlistentry>
<term><varname>$NOTIFY_SOCKET</varname></term>
- <listitem><para>Set by the init system
+ <listitem><para>Set by the service manager
for supervised processes for status
and start-up completion
notification. This environment variable
@@ -249,9 +278,9 @@
<example>
<title>Start-up Notification</title>
- <para>When a daemon finished starting up, it
+ <para>When a service finished starting up, it
might issue the following call to notify
- the init system:</para>
+ the service manager:</para>
<programlisting>sd_notify(0, "READY=1");</programlisting>
</example>
@@ -259,7 +288,7 @@
<example>
<title>Extended Start-up Notification</title>
- <para>A daemon could send the following after
+ <para>A service could send the following after
completing initialization:</para>
<programlisting>sd_notifyf(0, "READY=1\n"
@@ -271,7 +300,7 @@
<example>
<title>Error Cause Notification</title>
- <para>A daemon could send the following shortly before exiting, on failure</para>
+ <para>A service could send the following shortly before exiting, on failure</para>
<programlisting>sd_notifyf(0, "STATUS=Failed to start up: %s\n"
"ERRNO=%i",
diff --git a/src/core/service.c b/src/core/service.c
index 262a40cc8b..3221938793 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -92,6 +92,7 @@ static int service_dispatch_timer(sd_event_source *source, usec_t usec, void *us
static int service_dispatch_watchdog(sd_event_source *source, usec_t usec, void *userdata);
static void service_enter_signal(Service *s, ServiceState state, ServiceResult f);
+static void service_enter_reload_by_notify(Service *s);
static void service_init(Unit *u) {
Service *s = SERVICE(u);
@@ -473,7 +474,8 @@ static void service_dump(Unit *u, FILE *f, const char *prefix) {
"%sGuessMainPID: %s\n"
"%sType: %s\n"
"%sRestart: %s\n"
- "%sNotifyAccess: %s\n",
+ "%sNotifyAccess: %s\n"
+ "%sNotifyState: %s\n",
prefix, service_state_to_string(s->state),
prefix, service_result_to_string(s->result),
prefix, service_result_to_string(s->reload_result),
@@ -483,7 +485,8 @@ static void service_dump(Unit *u, FILE *f, const char *prefix) {
prefix, yes_no(s->guess_main_pid),
prefix, service_type_to_string(s->type),
prefix, service_restart_to_string(s->restart),
- prefix, notify_access_to_string(s->notify_access));
+ prefix, notify_access_to_string(s->notify_access),
+ prefix, notify_state_to_string(s->notify_state));
if (s->control_pid > 0)
fprintf(f,
@@ -1176,6 +1179,17 @@ fail:
service_enter_dead(s, SERVICE_FAILURE_RESOURCES, true);
}
+static void service_enter_stop_by_notify(Service *s) {
+ assert(s);
+
+ unit_watch_all_pids(UNIT(s));
+
+ if (s->timeout_stop_usec > 0)
+ service_arm_timer(s, s->timeout_stop_usec);
+
+ service_set_state(s, SERVICE_STOP);
+}
+
static void service_enter_stop(Service *s, ServiceResult f) {
int r;
@@ -1226,9 +1240,18 @@ static void service_enter_running(Service *s, ServiceResult f) {
cgroup_ok = cgroup_good(s);
if ((main_pid_ok > 0 || (main_pid_ok < 0 && cgroup_ok != 0)) &&
- (s->bus_name_good || s->type != SERVICE_DBUS))
- service_set_state(s, SERVICE_RUNNING);
- else if (s->remain_after_exit)
+ (s->bus_name_good || s->type != SERVICE_DBUS)) {
+
+ /* If there are any queued up sd_notify()
+ * notifications, process them now */
+ if (s->notify_state == NOTIFY_RELOADING)
+ service_enter_reload_by_notify(s);
+ else if (s->notify_state == NOTIFY_STOPPING)
+ service_enter_stop_by_notify(s);
+ else
+ service_set_state(s, SERVICE_RUNNING);
+
+ } else if (s->remain_after_exit)
service_set_state(s, SERVICE_EXITED);
else
service_enter_stop(s, SERVICE_SUCCESS);
@@ -1433,12 +1456,19 @@ static void service_enter_restart(Service *s) {
return;
fail:
- log_warning_unit(UNIT(s)->id,
- "%s failed to schedule restart job: %s",
- UNIT(s)->id, bus_error_message(&error, -r));
+ log_warning_unit(UNIT(s)->id, "%s failed to schedule restart job: %s", UNIT(s)->id, bus_error_message(&error, -r));
service_enter_dead(s, SERVICE_FAILURE_RESOURCES, false);
}
+static void service_enter_reload_by_notify(Service *s) {
+ assert(s);
+
+ if (s->timeout_start_usec > 0)
+ service_arm_timer(s, s->timeout_start_usec);
+
+ service_set_state(s, SERVICE_RELOAD);
+}
+
static void service_enter_reload(Service *s) {
int r;
@@ -1667,6 +1697,8 @@ static int service_start(Unit *u) {
s->status_text = NULL;
s->status_errno = 0;
+ s->notify_state = NOTIFY_UNKNOWN;
+
service_enter_start_pre(s);
return 0;
}
@@ -2504,13 +2536,15 @@ static int service_dispatch_watchdog(sd_event_source *source, usec_t usec, void
static void service_notify_message(Unit *u, pid_t pid, char **tags) {
Service *s = SERVICE(u);
- const char *e;
+ _cleanup_free_ char *cc = NULL;
bool notify_dbus = false;
+ const char *e;
assert(u);
- log_debug_unit(u->id, "%s: Got notification message from PID "PID_FMT" (%s...)",
- u->id, pid, tags && *tags ? tags[0] : "(empty)");
+ cc = strv_join(tags, ", ");
+ log_debug_unit(u->id, "%s: Got notification message from PID "PID_FMT" (%s)",
+ u->id, pid, isempty(cc) ? "n/a" : cc);
if (s->notify_access == NOTIFY_NONE) {
log_warning_unit(u->id, "%s: Got notification message from PID "PID_FMT", but reception is disabled.", u->id, pid);
@@ -2539,10 +2573,46 @@ static void service_notify_message(Unit *u, pid_t pid, char **tags) {
}
}
+ /* Interpret RELOADING= */
+ if (strv_find(tags, "RELOADING=1")) {
+
+ log_debug_unit(u->id, "%s: got RELOADING=1", u->id);
+ s->notify_state = NOTIFY_RELOADING;
+
+ if (s->state == SERVICE_RUNNING)
+ service_enter_reload_by_notify(s);
+
+ notify_dbus = true;
+ }
+
/* Interpret READY= */
- if (s->type == SERVICE_NOTIFY && s->state == SERVICE_START && strv_find(tags, "READY=1")) {
+ if (strv_find(tags, "READY=1")) {
+
log_debug_unit(u->id, "%s: got READY=1", u->id);
- service_enter_start_post(s);
+ s->notify_state = NOTIFY_READY;
+
+ /* Type=notify services inform us about completed
+ * initialization with READY=1 */
+ if (s->type == SERVICE_NOTIFY && s->state == SERVICE_START)
+ service_enter_start_post(s);
+
+ /* Sending READY=1 while we are reloading informs us
+ * that the reloading is complete */
+ if (s->state == SERVICE_RELOAD && s->control_pid == 0)
+ service_enter_running(s, SERVICE_SUCCESS);
+
+ notify_dbus = true;
+ }
+
+ /* Interpret STOPPING= */
+ if (strv_find(tags, "STOPPING=1")) {
+
+ log_debug_unit(u->id, "%s: got STOPPING=1", u->id);
+ s->notify_state = NOTIFY_STOPPING;
+
+ if (s->state == SERVICE_RUNNING)
+ service_enter_stop_by_notify(s);
+
notify_dbus = true;
}
@@ -2798,6 +2868,15 @@ static const char* const notify_access_table[_NOTIFY_ACCESS_MAX] = {
DEFINE_STRING_TABLE_LOOKUP(notify_access, NotifyAccess);
+static const char* const notify_state_table[_NOTIFY_STATE_MAX] = {
+ [NOTIFY_UNKNOWN] = "unknown",
+ [NOTIFY_READY] = "ready",
+ [NOTIFY_RELOADING] = "reloading",
+ [NOTIFY_STOPPING] = "stopping",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(notify_state, NotifyState);
+
static const char* const service_result_table[_SERVICE_RESULT_MAX] = {
[SERVICE_SUCCESS] = "success",
[SERVICE_FAILURE_RESOURCES] = "resources",
diff --git a/src/core/service.h b/src/core/service.h
index 686cf4b0bd..0227321d99 100644
--- a/src/core/service.h
+++ b/src/core/service.h
@@ -91,6 +91,15 @@ typedef enum NotifyAccess {
_NOTIFY_ACCESS_INVALID = -1
} NotifyAccess;
+typedef enum NotifyState {
+ NOTIFY_UNKNOWN,
+ NOTIFY_READY,
+ NOTIFY_RELOADING,
+ NOTIFY_STOPPING,
+ _NOTIFY_STATE_MAX,
+ _NOTIFY_STATE_INVALID = -1
+} NotifyState;
+
typedef enum ServiceResult {
SERVICE_SUCCESS,
SERVICE_FAILURE_RESOURCES,
@@ -196,6 +205,7 @@ struct Service {
PathSpec *pid_file_pathspec;
NotifyAccess notify_access;
+ NotifyState notify_state;
};
extern const UnitVTable service_vtable;
@@ -219,6 +229,9 @@ ServiceExecCommand service_exec_command_from_string(const char *s) _pure_;
const char* notify_access_to_string(NotifyAccess i) _const_;
NotifyAccess notify_access_from_string(const char *s) _pure_;
+const char* notify_state_to_string(NotifyState i) _const_;
+NotifyState notify_state_from_string(const char *s) _pure_;
+
const char* service_result_to_string(ServiceResult i) _const_;
ServiceResult service_result_from_string(const char *s) _pure_;
diff --git a/src/test/test-daemon.c b/src/test/test-daemon.c
index bcc049b325..7e0ac754d1 100644
--- a/src/test/test-daemon.c
+++ b/src/test/test-daemon.c
@@ -25,13 +25,29 @@
int main(int argc, char*argv[]) {
- sd_notify(0, "STATUS=Starting up");
+ sd_notify(0,
+ "STATUS=Starting up");
+ sleep(5);
+
+ sd_notify(0,
+ "STATUS=Running\n"
+ "READY=1");
+ sleep(5);
+
+ sd_notify(0,
+ "STATUS=Reloading\n"
+ "RELOADING=1");
sleep(5);
+
sd_notify(0,
"STATUS=Running\n"
"READY=1");
- sleep(10);
- sd_notify(0, "STATUS=Quitting");
+ sleep(5);
+
+ sd_notify(0,
+ "STATUS=Quitting\n"
+ "STOPPING=1");
+ sleep(5);
return 0;
}