Merge pull request #26 from draios/file-output

File output

digwatch.yaml

@@ -5,12 +5,12 @@ rules_file: /etc/digwatch.conf
 priority_level: warning
 
 syslog_output:
-  enabled: true
+  enabled: false
 
 file_output:
   enabled: true
-  filename: "bla.bla"
+  filename: ./events.txt
 
 stdout_output:
-  enabled: false
+  enabled: true
 

userspace/digwatch/digwatch.cpp

@@ -54,13 +54,13 @@ static void usage()
 }
 
 string lua_on_event = "on_event";
+string lua_add_output = "add_output";
 
 //
 // Event processing loop
 //
 void do_inspect(sinsp* inspector,
 		digwatch_rules* rules,
-		string output_name,
 		lua_State* ls)
 {
 	int32_t res;
@@ -110,9 +110,8 @@ void do_inspect(sinsp* inspector,
 		{
 			lua_pushlightuserdata(ls, ev);
 			lua_pushnumber(ls, ev->get_check_id());
-			lua_pushstring(ls, output_name.c_str());
 
-			if(lua_pcall(ls, 3, 0, 0) != 0)
+			if(lua_pcall(ls, 2, 0, 0) != 0)
 			{
 				const char* lerr = lua_tostring(ls, -1);
 				string err = "Error invoking function output: " + string(lerr);
@@ -157,6 +156,38 @@ void add_lua_path(lua_State *ls, string path)
 	lua_pop(ls, 1);
 }
 
+void add_output(lua_State *ls, output_config oc)
+{
+
+	uint8_t nargs = 1;
+	lua_getglobal(ls, lua_add_output.c_str());
+
+	if(!lua_isfunction(ls, -1))
+	{
+		throw sinsp_exception("No function " + lua_add_output + " found. ");
+	}
+	lua_pushstring(ls, oc.name.c_str());
+
+	// If we have options, build up a lua table containing them
+	if (oc.options.size())
+	{
+		nargs = 2;
+		lua_createtable(ls, 0, oc.options.size());
+
+		for (auto it = oc.options.cbegin(); it != oc.options.cend(); ++it)
+		{
+			lua_pushstring(ls, (*it).second.c_str());
+			lua_setfield(ls, -2, (*it).first.c_str());
+		}
+	}
+
+	if(lua_pcall(ls, nargs, 0, 0) != 0)
+	{
+		const char* lerr = lua_tostring(ls, -1);
+		throw sinsp_exception(string(lerr));
+	}
+
+}
 
 
 //
@@ -345,6 +376,11 @@ int digwatch_init(int argc, char **argv)
 
 		inspector->set_hostname_and_port_resolution_mode(false);
 
+		for(std::vector<output_config>::iterator it = config.m_outputs.begin(); it != config.m_outputs.end(); ++it)
+		{
+			add_output(ls, *it);
+		}
+
 		if (infile.size())
 		{
 			inspector->open(infile);
@@ -366,7 +402,6 @@ int digwatch_init(int argc, char **argv)
 		}
 		do_inspect(inspector,
 			   rules,
-			   output_name,
 			   ls);
 
 		inspector->close();

userspace/digwatch/lua/output.lua

@@ -9,6 +9,29 @@ function mod.stdout(evt, level, format)
    print (msg)
 end
 
+function mod.file_validate(options)
+   if (not type(options.filename) == 'string') then
+      error("File output needs to be configured with a valid filename")
+   end
+
+   file, err = io.open(options.filename, "a+")
+   if file == nil then
+      error("Error with file output: "..err)
+   end
+   file:close()
+
+end
+
+function mod.file(evt, level, format, options)
+   format = "%evt.time: "..levels[level+1].." "..format
+   formatter = digwatch.formatter(format)
+   msg = digwatch.format_event(evt, formatter)
+
+   file = io.open(options.filename, "a+")
+   file:write(msg, "\n")
+   file:close()
+end
+
 function mod.syslog(evt, level, format)
 
    formatter = digwatch.formatter(format)

userspace/digwatch/lua/rule_loader.lua

@@ -159,17 +159,33 @@ function on_done()
    io.flush()
 end
 
-local outputs = require('output')
+local output_functions = require('output')
 
-function on_event(evt_, rule_id, output_name)
-   if not (type(outputs[output_name]) == 'function') then
-      error("rule_loader.on_event(): invalid output_name: ", output_name)
+outputs = {}
+
+function add_output(output_name, config)
+   if not (type(output_functions[output_name]) == 'function') then
+      error("rule_loader.add_output(): invalid output_name: "..output_name)
    end
 
+   -- outputs can optionally define a validation function so that we don't
+   -- find out at runtime (when an event finally matches a rule!) that the config is invalid
+   if (type(output_functions[output_name.."_validate"]) == 'function') then
+     output_functions[output_name.."_validate"](config)
+   end
+
+   table.insert(outputs, {output = output_functions[output_name], config=config})
+end
+
+function on_event(evt_, rule_id)
+
    if state.outputs[rule_id] == nil then
       error ("rule_loader.on_event(): event with invalid rule_id: ", rule_id)
    end
 
-   outputs[output_name](evt_, state.outputs[rule_id].level, state.outputs[rule_id].format)
+   for index,o in ipairs(outputs) do
+      o.output(evt_, state.outputs[rule_id].level, state.outputs[rule_id].format, o.config)
+   end
+
 end