Remove dep on nixio by adding simple syslog lua function

userspace/digwatch/CMakeLists.txt

@@ -7,7 +7,7 @@ include_directories("${PROJECT_BINARY_DIR}/userspace/digwatch")
 include_directories("${CURL_INCLUDE_DIR}")
 include_directories("${LPEG_SRC}")
 
-add_executable(digwatch formats.cpp fields.cpp rules.cpp digwatch.cpp)
+add_executable(digwatch formats.cpp fields.cpp rules.cpp syslog.cpp digwatch.cpp)
 
 target_link_libraries(digwatch sinsp)
 target_link_libraries(digwatch "${LPEG_SRC}/lpeg.a")

userspace/digwatch/digwatch.cpp

@@ -22,6 +22,7 @@ extern "C" {
 #include "rules.h"
 #include "formats.h"
 #include "fields.h"
+#include "syslog.h"
 #include "utils.h"
 
 static bool g_terminate = false;
@@ -288,7 +289,7 @@ int digwatch_init(int argc, char **argv)
 		digwatch_formats::init(inspector, ls);
 		digwatch_fields::init(inspector, ls);
 
-		digwatch_fields::init(inspector, ls);
+		digwatch_syslog::init(ls);
 
 		rules->load_rules(rules_file);
 		inspector->set_filter(rules->get_filter());

userspace/digwatch/lua/output.lua

@@ -10,13 +10,10 @@ function mod.stdout(evt, level, format)
 end
 
 function mod.syslog(evt, level, format)
-   -- https://neopallium.github.io/nixio/modules/nixio.html#nixio.syslog
-   levels = {"emerg", "alert", "crit", "err", "warning", "notice", "info", "debug"}
 
-   nixio = require("nixio")
    formatter = digwatch.formatter(format)
    msg = digwatch.format_event(evt, formatter)
-   nixio.syslog(levels[level+1], msg)
+   digwatch.syslog(level, msg)
 end
 
 return mod

userspace/digwatch/syslog.cpp

@@ -0,0 +1,32 @@
+#include "syslog.h"
+#include "chisel_api.h"
+#include "filterchecks.h"
+
+#include <syslog.h>
+
+
+const static struct luaL_reg ll_digwatch [] =
+{
+	{"syslog", &digwatch_syslog::syslog},
+	{NULL,NULL}
+};
+
+
+void digwatch_syslog::init(lua_State *ls)
+{
+	luaL_openlib(ls, "digwatch", ll_digwatch, 0);
+}
+
+int digwatch_syslog::syslog(lua_State *ls) {
+	int priority = luaL_checknumber(ls, 1);
+
+	if (priority > LOG_DEBUG) {
+		return luaL_argerror(ls, 1, "digwatch.syslog: priority must be a number between 0 and 7");
+	}
+
+	const char *msg = luaL_checkstring(ls, 2);
+	::syslog(priority, "%s", msg);
+
+	return 0;
+}
+

userspace/digwatch/syslog.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include "sinsp.h"
+
+extern "C" {
+#include "lua.h"
+#include "lualib.h"
+#include "lauxlib.h"
+}
+
+class digwatch_syslog
+{
+ public:
+	static void init(lua_State *ls);
+
+	// value = digwatch.syslog(level, message)
+	static int syslog(lua_State *ls);
+};