manager: add DefaultEnvironment option

This complements existing functionality of setting variables
through 'systemctl set-environment', the kernel command line,
and through normal environment variables for systemd in session
mode.

man/systemd-system.conf.xml

@@ -262,6 +262,27 @@
                                 too.</para></listitem>
                         </varlistentry>
 
+                        <varlistentry>
+                                <term><varname>DefaultEnvironment=</varname></term>
+
+                                <listitem><para>Sets systemd manager
+                                environment variables for executed
+                                processes. Takes a space-separated
+                                list of variable assignments.
+                                </para>
+
+                                <para>Example:
+                                <programlisting>Environment="VAR1=word1 word2" VAR2=word3 "VAR3=word 5 6"</programlisting>
+                                gives three variables <literal>VAR1</literal>,
+                                <literal>VAR2</literal>, <literal>VAR3</literal>.
+                                </para>
+
+                                <para>
+                                See
+                                <citerefentry><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+                                for details about environment variables.</para></listitem>
+                        </varlistentry>
+
                         <varlistentry>
                                 <term><varname>DefaultLimitCPU=</varname></term>
                                 <term><varname>DefaultLimitFSIZE=</varname></term>

man/systemd.exec.xml

@@ -288,8 +288,9 @@
                                 variables is reset, all prior
                                 assignments have no effect.
                                 Variable expansion is not performed
-                                inside the strings, and $ has no special
-                                meaning.
+                                inside the strings, however, specifier
+                                expansion is possible. $ character has
+                                no special meaning.
                                 If you need to assign a value containing spaces
                                 to a variable, use double quotes (")
                                 for the assignment.</para>

src/core/load-fragment.c

@@ -1564,7 +1564,7 @@ int config_parse_environ(const char *unit,
         assert(filename);
         assert(lvalue);
         assert(rvalue);
-        assert(u);
+        assert(data);
 
         if (isempty(rvalue)) {
                 /* Empty assignment resets the list */
@@ -1573,7 +1573,11 @@ int config_parse_environ(const char *unit,
                 return 0;
         }
 
-        k = unit_full_printf(u, rvalue);
+        if (u)
+                k = unit_full_printf(u, rvalue);
+        else
+                k = strdup(rvalue);
+
         if (!k)
                 return log_oom();
 

src/core/main.c

@@ -94,6 +94,7 @@ static ExecOutput arg_default_std_output = EXEC_OUTPUT_JOURNAL;
 static ExecOutput arg_default_std_error = EXEC_OUTPUT_INHERIT;
 static usec_t arg_runtime_watchdog = 0;
 static usec_t arg_shutdown_watchdog = 10 * USEC_PER_MINUTE;
+static char **arg_default_environment = NULL;
 static struct rlimit *arg_default_rlimit[RLIMIT_NLIMITS] = {};
 static uint64_t arg_capability_bounding_set_drop = 0;
 static nsec_t arg_timer_slack_nsec = (nsec_t) -1;
@@ -646,6 +647,7 @@ static int parse_config_file(void) {
                 { "Manager", "ShutdownWatchdogSec",   config_parse_sec,          0, &arg_shutdown_watchdog   },
                 { "Manager", "CapabilityBoundingSet", config_parse_bounding_set, 0, &arg_capability_bounding_set_drop },
                 { "Manager", "TimerSlackNSec",        config_parse_nsec,         0, &arg_timer_slack_nsec    },
+                { "Manager", "DefaultEnvironment",    config_parse_environ,      0, &arg_default_environment },
                 { "Manager", "DefaultLimitCPU",       config_parse_limit,        0, &arg_default_rlimit[RLIMIT_CPU]},
                 { "Manager", "DefaultLimitFSIZE",     config_parse_limit,        0, &arg_default_rlimit[RLIMIT_FSIZE]},
                 { "Manager", "DefaultLimitDATA",      config_parse_limit,        0, &arg_default_rlimit[RLIMIT_DATA]},
@@ -1630,6 +1632,9 @@ int main(int argc, char *argv[]) {
         if (arg_default_controllers)
                 manager_set_default_controllers(m, arg_default_controllers);
 
+        if (arg_default_environment)
+                manager_set_default_environment(m, arg_default_environment);
+
         manager_set_show_status(m, arg_show_status);
 
         /* Remember whether we should queue the default job */

src/core/manager.c

@@ -2570,6 +2570,18 @@ void manager_undo_generators(Manager *m) {
         remove_generator_dir(m, &m->generator_unit_path_late);
 }
 
+int manager_set_default_environment(Manager *m, char **environment) {
+
+        char **e = NULL;
+        assert(m);
+        e = strv_env_merge(2, m->environment, environment);
+        if (!e)
+                return -ENOMEM;
+        strv_free(m->environment);
+        m->environment = e;
+        return 0;
+}
+
 int manager_set_default_controllers(Manager *m, char **controllers) {
         char **l;
 

src/core/manager.h

@@ -272,6 +272,7 @@ unsigned manager_dispatch_load_queue(Manager *m);
 unsigned manager_dispatch_run_queue(Manager *m);
 unsigned manager_dispatch_dbus_queue(Manager *m);
 
+int manager_set_default_environment(Manager *m, char **environment);
 int manager_set_default_controllers(Manager *m, char **controllers);
 int manager_set_default_rlimits(Manager *m, struct rlimit **default_rlimit);
 

src/core/system.conf

@@ -25,6 +25,7 @@
 #ShutdownWatchdogSec=10min
 #CapabilityBoundingSet=
 #TimerSlackNSec=
+#DefaultEnvironment=
 #DefaultLimitCPU=
 #DefaultLimitFSIZE=
 #DefaultLimitDATA=