networkctl: support edit --stdin

src/network/networkctl-config-file.c

@@ -396,23 +396,30 @@ static int reload_daemons(ReloadFlags flags) {
 }
 
 int verb_edit(int argc, char *argv[], void *userdata) {
+        char **args = ASSERT_PTR(strv_skip(argv, 1));
         _cleanup_(edit_file_context_done) EditFileContext context = {
                 .marker_start = DROPIN_MARKER_START,
                 .marker_end = DROPIN_MARKER_END,
                 .remove_parent = !!arg_drop_in,
+                .stdin = arg_stdin,
         };
         _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
         ReloadFlags reload = 0;
         int r;
 
-        if (!on_tty())
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot edit network config files if not on a tty.");
+        if (!on_tty() && !arg_stdin)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot edit network config files interactively if not on a tty.");
+
+        /* Duplicating main configs makes no sense. This also mimics the behavior of systemctl. */
+        if (arg_stdin && !arg_drop_in && strv_length(args) != 1)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "When 'edit --stdin' without '--drop-in=', exactly one config file for editing must be specified.");
 
         r = mac_selinux_init();
         if (r < 0)
                 return r;
 
-        STRV_FOREACH(name, strv_skip(argv, 1)) {
+        STRV_FOREACH(name, args) {
                 _cleanup_strv_free_ char **dropins = NULL;
                 _cleanup_free_ char *path = NULL;
                 const char *link_config;

src/network/networkctl.c

@@ -91,6 +91,7 @@ bool arg_all = false;
 bool arg_stats = false;
 bool arg_full = false;
 bool arg_runtime = false;
+bool arg_stdin = false;
 unsigned arg_lines = 10;
 char *arg_drop_in = NULL;
 sd_json_format_flags_t arg_json_format_flags = SD_JSON_FORMAT_OFF;
@@ -3025,6 +3026,7 @@ static int help(void) {
                "                         after editing network config\n"
                "     --drop-in=NAME      Edit specified drop-in instead of main config file\n"
                "     --runtime           Edit runtime config files\n"
+               "     --stdin             Read new contents of edited file from stdin\n"
                "\nSee the %s for details.\n",
                program_invocation_short_name,
                ansi_highlight(),
@@ -3043,6 +3045,7 @@ static int parse_argv(int argc, char *argv[]) {
                 ARG_NO_RELOAD,
                 ARG_DROP_IN,
                 ARG_RUNTIME,
+                ARG_STDIN,
         };
 
         static const struct option options[] = {
@@ -3058,6 +3061,7 @@ static int parse_argv(int argc, char *argv[]) {
                 { "no-reload", no_argument,       NULL, ARG_NO_RELOAD },
                 { "drop-in",   required_argument, NULL, ARG_DROP_IN   },
                 { "runtime",   no_argument,       NULL, ARG_RUNTIME   },
+                { "stdin",     no_argument,       NULL, ARG_STDIN     },
                 {}
         };
 
@@ -3092,6 +3096,10 @@ static int parse_argv(int argc, char *argv[]) {
                         arg_runtime = true;
                         break;
 
+                case ARG_STDIN:
+                        arg_stdin = true;
+                        break;
+
                 case ARG_DROP_IN:
                         if (isempty(optarg))
                                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Empty drop-in file name.");

src/network/networkctl.h

@@ -15,6 +15,7 @@ extern bool arg_all;
 extern bool arg_stats;
 extern bool arg_full;
 extern bool arg_runtime;
+extern bool arg_stdin;
 extern unsigned arg_lines;
 extern char *arg_drop_in;
 extern sd_json_format_flags_t arg_json_format_flags;