Merge pull request syslog-ng#5016 from therandomstring/filter-sev-numeric-fix

Add numeric value setting to level filter

Author: therandomstring

lib/filter/filter-expr-grammar.ym

@@ -146,6 +146,7 @@ filter_simple_expr
 	: KW_FACILITY '(' filter_fac_list ')'	{ $$ = filter_facility_new($3);  }
 	| KW_FACILITY '(' LL_NUMBER ')'		{ $$ = filter_facility_new(0x80000000 | $3); }
 	| KW_SEVERITY '(' filter_severity_list ')' { $$ = filter_severity_new($3); }
+	| KW_SEVERITY '(' LL_NUMBER ')'		{ $$ = filter_severity_new( 1 << $3); }
 	| KW_FILTER '(' string ')'		{ $$ = filter_call_new($3, configuration); free($3); }
 	| KW_NETMASK '(' string ')'    { $$ = filter_netmask_new($3); free($3); }
         | KW_NETMASK6 '(' string ')'   {

news/feature-5016.md

@@ -0,0 +1,18 @@
+`filter`: Added numerical severity settings.
+
+The `level` filter option now accepts numerical values similar to `facility`.
+
+Example config:
+```
+filter f_severity {
+  level(4)
+};
+```
+This is equivalent to
+```
+filter f_severity {
+  level("warning")
+};
+```
+
+For more information, consult the [documentation](https://syslog-ng.github.io/admin-guide/080_Log/030_Filters/005_Filter_functions/004_level_priority.html).