Value parser, for parsing a single value into a metric

closes #849

internal/config/config.go

@@ -701,12 +701,21 @@ func buildParser(name string, tbl *ast.Table) (parsers.Parser, error) {
 		}
 	}
 
+	if node, ok := tbl.Fields["data_type"]; ok {
+		if kv, ok := node.(*ast.KeyValue); ok {
+			if str, ok := kv.Value.(*ast.String); ok {
+				c.DataType = str.Value
+			}
+		}
+	}
+
 	c.MetricName = name
 
 	delete(tbl.Fields, "data_format")
 	delete(tbl.Fields, "separator")
 	delete(tbl.Fields, "templates")
 	delete(tbl.Fields, "tag_keys")
+	delete(tbl.Fields, "data_type")
 
 	return parsers.NewParser(c)
 }