analyze: add get-log-level, get-log-target verbs

They’re counterparts to the existing set-log-level and set-log-target
verbs, simply printing the current value to stdout. This makes it
slightly easier to temporarily change the log level and/or target and
then restore the old value(s).

5 files changed, 86 insertions, 1 deletions

diff --git a/NEWS b/NEWS
index f843c35c4f..4940902451 100644
--- a/NEWS
+++ b/NEWS
@@ -11,6 +11,11 @@ CHANGES WITH 235:
           that case users will be prevented from correctly managing bond0
           interface using networkd.
 
+        * systemd-analyze gained new verbs "get-log-level" and "get-log-target"
+          which print the logging level and target of the system manager,
+          respectively. They complement the existing "set-log-level" and
+          "set-log-target" verbs, which can be used to change those values.
+
 CHANGES WITH 234:
 
         * Meson is now supported as build system in addition to Automake. It is
diff --git a/man/systemd-analyze.xml b/man/systemd-analyze.xml
index 91edbfb3b5..a3a3ce0e54 100644
--- a/man/systemd-analyze.xml
+++ b/man/systemd-analyze.xml
@@ -104,6 +104,16 @@
     <cmdsynopsis>
       <command>systemd-analyze</command>
       <arg choice="opt" rep="repeat">OPTIONS</arg>
+      <arg choice="plain">get-log-level</arg>
+    </cmdsynopsis>
+    <cmdsynopsis>
+      <command>systemd-analyze</command>
+      <arg choice="opt" rep="repeat">OPTIONS</arg>
+      <arg choice="plain">get-log-target</arg>
+    </cmdsynopsis>
+    <cmdsynopsis>
+      <command>systemd-analyze</command>
+      <arg choice="opt" rep="repeat">OPTIONS</arg>
       <arg choice="plain">syscall-filter</arg>
       <arg choice="opt"><replaceable>SET</replaceable>…</arg>
     </cmdsynopsis>
@@ -187,6 +197,12 @@
     <option>--log-target=</option>, described in
     <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>).</para>
 
+    <para><command>systemd-analyze get-log-level</command>
+    prints the current log level of the <command>systemd</command> daemon.</para>
+
+    <para><command>systemd-analyze get-log-target</command>
+    prints the current log target of the <command>systemd</command> daemon.</para>
+
     <para><command>systemd-analyze syscall-filter <optional><replaceable>SET</replaceable>…</optional></command>
     will list system calls contained in the specified system call set <replaceable>SET</replaceable>,
     or all known sets if no sets are specified. Argument <replaceable>SET</replaceable> must include
diff --git a/shell-completion/bash/systemd-analyze b/shell-completion/bash/systemd-analyze
index 75352a7b3e..8c56a1cf9a 100644
--- a/shell-completion/bash/systemd-analyze
+++ b/shell-completion/bash/systemd-analyze
@@ -40,7 +40,7 @@ _systemd_analyze() {
         )
 
         local -A VERBS=(
-                [STANDALONE]='time blame plot dump'
+                [STANDALONE]='time blame plot dump get-log-level get-log-target'
                 [CRITICAL_CHAIN]='critical-chain'
                 [DOT]='dot'
                 [LOG_LEVEL]='set-log-level'
diff --git a/shell-completion/zsh/_systemd-analyze b/shell-completion/zsh/_systemd-analyze
index 3f091e326a..22b4c181a1 100644
--- a/shell-completion/zsh/_systemd-analyze
+++ b/shell-completion/zsh/_systemd-analyze
@@ -28,6 +28,8 @@ _systemd_analyze_command(){
         'dump:Dump server status'
         'set-log-level:Set systemd log threshold'
         'set-log-target:Set systemd log target'
+        'get-log-level:Get systemd log threshold'
+        'get-log-target:Get systemd log target'
         'syscall-filter:List syscalls in seccomp filter'
         'verify:Check unit files for correctness'
     )
diff --git a/src/analyze/analyze.c b/src/analyze/analyze.c
index 1eb2ca0ccf..a6a36a3d2e 100644
--- a/src/analyze/analyze.c
+++ b/src/analyze/analyze.c
@@ -1253,6 +1253,34 @@ static int set_log_level(sd_bus *bus, char **args) {
         return 0;
 }
 
+static int get_log_level(sd_bus *bus, char **args) {
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        int r;
+        _cleanup_free_ char *level = NULL;
+
+        assert(bus);
+        assert(args);
+
+        if (!strv_isempty(args)) {
+                log_error("Too many arguments.");
+                return -E2BIG;
+        }
+
+        r = sd_bus_get_property_string(
+                        bus,
+                        "org.freedesktop.systemd1",
+                        "/org/freedesktop/systemd1",
+                        "org.freedesktop.systemd1.Manager",
+                        "LogLevel",
+                        &error,
+                        &level);
+        if (r < 0)
+                return log_error_errno(r, "Failed to get log level: %s", bus_error_message(&error, r));
+
+        puts(level);
+        return 0;
+}
+
 static int set_log_target(sd_bus *bus, char **args) {
         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
         int r;
@@ -1280,6 +1308,34 @@ static int set_log_target(sd_bus *bus, char **args) {
         return 0;
 }
 
+static int get_log_target(sd_bus *bus, char **args) {
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        int r;
+        _cleanup_free_ char *target = NULL;
+
+        assert(bus);
+        assert(args);
+
+        if (!strv_isempty(args)) {
+                log_error("Too many arguments.");
+                return -E2BIG;
+        }
+
+        r = sd_bus_get_property_string(
+                        bus,
+                        "org.freedesktop.systemd1",
+                        "/org/freedesktop/systemd1",
+                        "org.freedesktop.systemd1.Manager",
+                        "LogTarget",
+                        &error,
+                        &target);
+        if (r < 0)
+                return log_error_errno(r, "Failed to get log target: %s", bus_error_message(&error, r));
+
+        puts(target);
+        return 0;
+}
+
 #ifdef HAVE_SECCOMP
 static void dump_syscall_filter(const SyscallFilterSet *set) {
         const char *syscall;
@@ -1365,6 +1421,8 @@ static void help(void) {
                "  dot                      Output dependency graph in man:dot(1) format\n"
                "  set-log-level LEVEL      Set logging threshold for manager\n"
                "  set-log-target TARGET    Set logging target for manager\n"
+               "  get-log-level            Get logging threshold for manager\n"
+               "  get-log-target           Get logging target for manager\n"
                "  dump                     Output state serialization of service manager\n"
                "  syscall-filter [NAME...] Print list of syscalls in seccomp filter\n"
                "  verify FILE...           Check unit files for correctness\n"
@@ -1532,8 +1590,12 @@ int main(int argc, char *argv[]) {
                         r = dump(bus, argv+optind+1);
                 else if (streq(argv[optind], "set-log-level"))
                         r = set_log_level(bus, argv+optind+1);
+                else if (streq(argv[optind], "get-log-level"))
+                        r = get_log_level(bus, argv+optind+1);
                 else if (streq(argv[optind], "set-log-target"))
                         r = set_log_target(bus, argv+optind+1);
+                else if (streq(argv[optind], "get-log-target"))
+                        r = get_log_target(bus, argv+optind+1);
                 else if (streq(argv[optind], "syscall-filter"))
                         r = dump_syscall_filters(argv+optind+1);
                 else