Puppet manifest has a file declaration that somehow duplicates itself

Question

Given the confusing error message:

err: Could not retrieve catalog from remote server: Error 400 on SERVER: Duplicate declaration: File[/etc/logstas

Answer 1

Defined types should not declare common resources, meaning such that are not derived from the define instances $name.

In your example, the directory is a resource that many instances of your define need. It should therefor move to a (perhaps dedicated) class.

class logstash::config_dir {
    file { "${logstash::params::config_dir}":
        ensure  => directory,
        owner   => root,
        group   => root,
        mode    => '0755',
        purge   => true,
    }
}

In your define, you just

include logstash::config_dir

Including a class multiple times poses no problem and solves exactly that problem (among others).