core: automatically update StandardOuput=syslog to =journal (and simi…

…lar for StandardError=)

Let's go one step further and upgrade implicitly. Usually =syslog
assignments are historic artifacts only. Let's upgrade the lines
automatically, and politely suggest people update their unit
files/configuration (and drop the lines altogether, without
replacement).

Fixes: #15807

src/core/execute.c

@@ -219,17 +219,10 @@ static bool is_terminal_input(ExecInput i) {
 static bool is_terminal_output(ExecOutput o) {
         return IN_SET(o,
                       EXEC_OUTPUT_TTY,
-                      EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
                       EXEC_OUTPUT_KMSG_AND_CONSOLE,
                       EXEC_OUTPUT_JOURNAL_AND_CONSOLE);
 }
 
-static bool is_syslog_output(ExecOutput o) {
-        return IN_SET(o,
-                      EXEC_OUTPUT_SYSLOG,
-                      EXEC_OUTPUT_SYSLOG_AND_CONSOLE);
-}
-
 static bool is_kmsg_output(ExecOutput o) {
         return IN_SET(o,
                       EXEC_OUTPUT_KMSG,
@@ -361,7 +354,7 @@ static int connect_logger_as(
                 params->flags & EXEC_PASS_LOG_UNIT ? unit->id : "",
                 context->syslog_priority,
                 !!context->syslog_level_prefix,
-                is_syslog_output(output),
+                false,
                 is_kmsg_output(output),
                 is_terminal_output(output)) < 0)
                 return -errno;
@@ -664,8 +657,6 @@ static int setup_output(
                 /* We don't reset the terminal if this is just about output */
                 return open_terminal_as(exec_context_tty_path(context), O_WRONLY, fileno);
 
-        case EXEC_OUTPUT_SYSLOG:
-        case EXEC_OUTPUT_SYSLOG_AND_CONSOLE:
         case EXEC_OUTPUT_KMSG:
         case EXEC_OUTPUT_KMSG_AND_CONSOLE:
         case EXEC_OUTPUT_JOURNAL:
@@ -4736,17 +4727,13 @@ void exec_context_dump(const ExecContext *c, FILE* f, const char *prefix) {
                         prefix, yes_no(c->tty_vt_disallocate));
 
         if (IN_SET(c->std_output,
-                   EXEC_OUTPUT_SYSLOG,
                    EXEC_OUTPUT_KMSG,
                    EXEC_OUTPUT_JOURNAL,
-                   EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
                    EXEC_OUTPUT_KMSG_AND_CONSOLE,
                    EXEC_OUTPUT_JOURNAL_AND_CONSOLE) ||
             IN_SET(c->std_error,
-                   EXEC_OUTPUT_SYSLOG,
                    EXEC_OUTPUT_KMSG,
                    EXEC_OUTPUT_JOURNAL,
-                   EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
                    EXEC_OUTPUT_KMSG_AND_CONSOLE,
                    EXEC_OUTPUT_JOURNAL_AND_CONSOLE)) {
 
@@ -5764,8 +5751,6 @@ static const char* const exec_output_table[_EXEC_OUTPUT_MAX] = {
         [EXEC_OUTPUT_INHERIT] = "inherit",
         [EXEC_OUTPUT_NULL] = "null",
         [EXEC_OUTPUT_TTY] = "tty",
-        [EXEC_OUTPUT_SYSLOG] = "syslog",
-        [EXEC_OUTPUT_SYSLOG_AND_CONSOLE] = "syslog+console",
         [EXEC_OUTPUT_KMSG] = "kmsg",
         [EXEC_OUTPUT_KMSG_AND_CONSOLE] = "kmsg+console",
         [EXEC_OUTPUT_JOURNAL] = "journal",

src/core/execute.h

@@ -52,8 +52,6 @@ typedef enum ExecOutput {
         EXEC_OUTPUT_INHERIT,
         EXEC_OUTPUT_NULL,
         EXEC_OUTPUT_TTY,
-        EXEC_OUTPUT_SYSLOG,
-        EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
         EXEC_OUTPUT_KMSG,
         EXEC_OUTPUT_KMSG_AND_CONSOLE,
         EXEC_OUTPUT_JOURNAL,

src/core/load-fragment.c

@@ -1099,6 +1099,7 @@ int config_parse_exec_output(
         const char *n;
         ExecContext *c = data;
         const Unit *u = userdata;
+        bool obsolete = false;
         ExecOutput eo;
         int r;
 
@@ -1123,6 +1124,14 @@ int config_parse_exec_output(
 
                 eo = EXEC_OUTPUT_NAMED_FD;
 
+        } else if (streq(rvalue, "syslog")) {
+                eo = EXEC_OUTPUT_JOURNAL;
+                obsolete = true;
+
+        } else if (streq(rvalue, "syslog+console")) {
+                eo = EXEC_OUTPUT_JOURNAL_AND_CONSOLE;
+                obsolete = true;
+
         } else if ((n = startswith(rvalue, "file:"))) {
 
                 r = unit_full_printf(u, n, &resolved);
@@ -1154,6 +1163,11 @@ int config_parse_exec_output(
                 }
         }
 
+        if (obsolete)
+                log_syntax(unit, LOG_NOTICE, filename, line, 0,
+                           "Standard output type %s is obsolete, automatically updating to %s. Please update your unit file, and consider removing the setting altogether.",
+                           rvalue, exec_output_to_string(eo));
+
         if (streq(lvalue, "StandardOutput")) {
                 if (eo == EXEC_OUTPUT_NAMED_FD)
                         free_and_replace(c->stdio_fdname[STDOUT_FILENO], resolved);
@@ -5051,23 +5065,37 @@ int config_parse_output_restricted(
                 void *userdata) {
 
         ExecOutput t, *eo = data;
+        bool obsolete = false;
 
         assert(filename);
         assert(lvalue);
         assert(rvalue);
         assert(data);
 
-        t = exec_output_from_string(rvalue);
-        if (t < 0) {
-                log_syntax(unit, LOG_ERR, filename, line, 0, "Failed to parse output type, ignoring: %s", rvalue);
-                return 0;
-        }
+        if (streq(rvalue, "syslog")) {
+                t = EXEC_OUTPUT_JOURNAL;
+                obsolete = true;
+        } else if (streq(rvalue, "syslog+console")) {
+                t = EXEC_OUTPUT_JOURNAL_AND_CONSOLE;
+                obsolete = true;
+        } else {
+                t = exec_output_from_string(rvalue);
+                if (t < 0) {
+                        log_syntax(unit, LOG_ERR, filename, line, 0, "Failed to parse output type, ignoring: %s", rvalue);
+                        return 0;
+                }
 
-        if (IN_SET(t, EXEC_OUTPUT_SOCKET, EXEC_OUTPUT_NAMED_FD, EXEC_OUTPUT_FILE, EXEC_OUTPUT_FILE_APPEND)) {
-                log_syntax(unit, LOG_ERR, filename, line, 0, "Standard output types socket, fd:, file:, append: are not supported as defaults, ignoring: %s", rvalue);
-                return 0;
+                if (IN_SET(t, EXEC_OUTPUT_SOCKET, EXEC_OUTPUT_NAMED_FD, EXEC_OUTPUT_FILE, EXEC_OUTPUT_FILE_APPEND)) {
+                        log_syntax(unit, LOG_ERR, filename, line, 0, "Standard output types socket, fd:, file:, append: are not supported as defaults, ignoring: %s", rvalue);
+                        return 0;
+                }
         }
 
+        if (obsolete)
+                log_syntax(unit, LOG_NOTICE, filename, line, 0,
+                           "Standard output type %s is obsolete, automatically updating to %s. Please update your configuration.",
+                           rvalue, exec_output_to_string(t));
+
         *eo = t;
         return 0;
 }

src/core/unit.c

@@ -1123,12 +1123,10 @@ int unit_add_exec_dependencies(Unit *u, ExecContext *c) {
 
         if (!IN_SET(c->std_output,
                     EXEC_OUTPUT_JOURNAL, EXEC_OUTPUT_JOURNAL_AND_CONSOLE,
-                    EXEC_OUTPUT_KMSG, EXEC_OUTPUT_KMSG_AND_CONSOLE,
-                    EXEC_OUTPUT_SYSLOG, EXEC_OUTPUT_SYSLOG_AND_CONSOLE) &&
+                    EXEC_OUTPUT_KMSG, EXEC_OUTPUT_KMSG_AND_CONSOLE) &&
             !IN_SET(c->std_error,
                     EXEC_OUTPUT_JOURNAL, EXEC_OUTPUT_JOURNAL_AND_CONSOLE,
-                    EXEC_OUTPUT_KMSG, EXEC_OUTPUT_KMSG_AND_CONSOLE,
-                    EXEC_OUTPUT_SYSLOG, EXEC_OUTPUT_SYSLOG_AND_CONSOLE) &&
+                    EXEC_OUTPUT_KMSG, EXEC_OUTPUT_KMSG_AND_CONSOLE) &&
             !c->log_namespace)
                 return 0;