The JSON parser is the simplest option: if the original log source is a JSON map string, it will take it structure and convert it directly to the internal binary representation.
A simple configuration that can be found in the default parsers configuration file, is the entry to parse Docker log files (when the tail input plugin is used):
The following log entry is a valid content for the parser defined above:
After processing, it internal representation will be:
The time has been converted to Unix timestamp (UTC) and the map reduced to each component of the original message.