This is more of a note to the future myself rather than a proper post. However...

I've got an error trying to synchronize elasticsearch and postgresql using logstash. My configurations was along the lines of

input {
    jdbc {
        jdbc_connection_string => "jdbc:postgresql://192.168.2.156:5432/chiaki"
        jdbc_user => "chiaki"
        jdbc_driver_library => "/path/to/postgresql-42.2.12.jre7.jar"
        jdbc_driver_class => "org.postgresql.Driver"
        jdbc_validate_connection => true
        statement => "select * from foo"
    }
}

output {
    elasticsearch {
        hosts => ["http://localhost:9200"]
        index => "foo"
        document_id => "%{the_pk}"
        doc_as_upsert => true
    }
}

But it error'd with something like "role _logstash does not exists."

I haven't really tracked down the issued, but found a workaround: specify the user also in the connection string.

It's quite strange, since the jdbc_user params is required.

P.S. the error was about a missing _logstash role because on OpenBSD that user is created for logstash. This was a hint that jdbc_user wasn't respected.