Loaded cf-reactor as a dynamic library

Changelog: Title
Signed-off-by: Victor Moene <victor.moene@northern.tech>

Author: victormlg

cf-reactor/cf-reactor.c

@@ -1,7 +1,168 @@
+/*
+  Copyright 2026 Northern.tech AS
+
+  This file is part of CFEngine 3 - written and maintained by Northern.tech AS.
+
+  This program is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by the
+  Free Software Foundation; version 3.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA
+
+  To the extent this program is licensed as part of the Enterprise
+  versions of CFEngine, the applicable Commercial Open Source License
+  (COSL) may apply to this file if you as a licensee so wish it. See
+  included file COSL.txt.
+*/
+
+
+#include <platform.h>
+#include <extensions.h>
+#include <logging.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <writer.h>
+#include <config.h>
+#include <generic_agent.h>
+#include <man.h>
+#include <cleanup.h>
+
+#define REACTOR_NOVA_LIBRARY_NAME "cfengine-reactor-nova.so"
 
-int main()
+typedef int (*ReactorNovaMainFn)(bool no_fork);
+
+static const Component COMPONENT =
+{
+    .name = "cf-reactor",
+    .website = CF_WEBSITE,
+    .copyright = CF_COPYRIGHT
+};
+
+static const char *const CF_REACTOR_SHORT_DESCRIPTION = "CFEngine event reaction daemon";
+
+static const char *const CF_REACTOR_MANPAGE_LONG_DESCRIPTION =
+        "cf-reactor is a daemon reacting on events, currently only NOTIFY events from PostgreSQL.";
+
+static const struct option OPTIONS[] =
+{
+    {"debug", no_argument, 0, 'd'},
+    {"no-fork", no_argument, 0, 'F'},
+    {"log-level", required_argument, 0, 'g'},
+    {"help", no_argument, 0, 'h'},
+    {"inform", no_argument, 0, 'I'},
+    {"timestamp", no_argument, 0, 'l'},
+    {"verbose", no_argument, 0, 'v'},
+    {"version", no_argument, 0, 'V'},
+    {NULL, 0, 0, '\0'}
+};
+
+static const char *const HINTS[] =
 {
-    printf("Hello cf-reactor!\n");
-    return 0;
-}
+    "Enable debugging output and run in foreground",
+    "Run as a foreground process (do not fork)",
+    "Specify how detailed logs should be. Possible values: 'error', 'warning', 'notice', 'info', 'verbose', 'debug'",
+    "Print the help message",
+    "Print basic information about actions being taken",
+    "Log timestamps on each line of log output",
+    "Output verbose information about the behaviour of the agent",
+    "Output the version of the software",
+    NULL
+};
+
+int main(int argc, char *argv[])
+{
+    bool no_fork = false;
+
+    extern char *optarg;
+    int longopt_idx;
+    int c;
+    while ((c = getopt_long(argc, argv, "dFg:hIlMvV",
+                            OPTIONS, &longopt_idx))
+           != -1)
+    {
+        switch (c)
+        {
+        case 'd':
+            LogSetGlobalLevel(LOG_LEVEL_DEBUG);
+            no_fork = true;
+            break;
+
+        case 'F':
+            no_fork = true;
+            break;
+
+        case 'g':
+            LogSetGlobalLevelArgOrExit(optarg);
+            break;
+
+        case 'h':
+            {
+                Writer *w = FileWriter(stdout);
+                WriterWriteHelp(w, &COMPONENT, OPTIONS, HINTS, NULL, false, true);
+                FileWriterDetach(w);
+            }
+            DoCleanupAndExit(EXIT_SUCCESS);
+
+        case 'I':
+            LogSetGlobalLevel(LOG_LEVEL_INFO);
+            break;
+
+        case 'l':
+            LoggingEnableTimestamps(true);
+            break;
+
+        case 'M':
+            {
+                Writer *out = FileWriter(stdout);
+                ManPageWrite(out, "cf-reactor", time(NULL),
+                             CF_REACTOR_SHORT_DESCRIPTION,
+                             CF_REACTOR_MANPAGE_LONG_DESCRIPTION,
+                             OPTIONS, HINTS,
+                             NULL, false,
+                             true);
+                FileWriterDetach(out);
+                DoCleanupAndExit(EXIT_SUCCESS);
+            }
+
+        case 'v':
+            LogSetGlobalLevel(LOG_LEVEL_VERBOSE);
+            no_fork = true;
+            break;
+
+        case 'V':
+            {
+                Writer *w = FileWriter(stdout);
+                GenericAgentWriteVersion(w);
+                FileWriterDetach(w);
+            }
+            DoCleanupAndExit(EXIT_SUCCESS);
+
+        }
+    }
+
+    void *handle = extension_library_open(REACTOR_NOVA_LIBRARY_NAME);
+    if (!handle)
+    {
+        Log(LOG_LEVEL_INFO, "Nova extension library '%s' not loaded or not available.", REACTOR_NOVA_LIBRARY_NAME);
+        Log(LOG_LEVEL_INFO, "Running open-source cf-reactor.");
+        return 0;
+    }
+
+    ReactorNovaMainFn ReactorNovaMain = (ReactorNovaMainFn) shlib_load(handle, "ReactorNovaMain");
+    if (!ReactorNovaMain)
+    {
+        Log(LOG_LEVEL_ERR, "Failed to load ReactorNovaMain symbol from '%s'.", REACTOR_NOVA_LIBRARY_NAME);
+        extension_library_close(handle);
+        return 1;
+    }
+
+
+    return ReactorNovaMain(no_fork);
+}