Failed to execute action {:action=>LogStash::PipelineAction::Create/pipeline_id:main, :exception=>"LogStash::ConfigurationError", :message=>"Expected one of [A-Za-z0-9_-], [ \\t\\r\\n]

As far as I know, there is no official logstash MongoDB Input plugin. there is an output plugin though MongoDB output plugin

Then you might be able to use the JDBC input

Also there is an article to configure MongoDB using jdbc

See also another thread in similar option