If it can't connect to lldpd daemon custom fact lldp should not return MalformedDataError

[kBite]

Affected Puppet, Ruby, OS and module versions/distributions

• Puppet: 7.x, 8.x
• Ruby: 2.7.x, 3.2.x
• Distribution: AlmaLinux 8, AlmaLinux 9
• Module version: every version since v3.3.0-2-g14a43

How to reproduce ( including debug output)

# facter -p lldp
[2023-05-03 18:29:28.181294 ] WARN Facter - invalid or malformed lldp data: MalformedDataError: no lldp interface data found

# facter --debug -p lldp
...
[2023-05-03 18:27:41.184214 ] DEBUG Facter::FactLoader - Loading external facts
[2023-05-03 18:27:41.185501 ] DEBUG Facter::QueryParser - List of resolvable facts: [#<Facter::SearchedFact:0x00007fc09c46b950 @name="lldp", @fact_class=nil, @user_query="lldp", @type=:custom, @file=nil>]
[2023-05-03 18:27:41.185733 ] DEBUG Facter::Core::Execution::Posix - Executing command: /sbin/lldpctl -f json
[2023-05-03 18:27:41.191637 ] DEBUG lldpctl -f json - Command /sbin/lldpctl -f json completed with the following stderr message: 2023-05-03T18:27:41 [WARN/control] unable to connect to socket /run/lldpd/lldpd.socket: No such fil
e or directory
2023-05-03T18:27:41 [WARN/lldpctl] not able to get the list of interfaces. Unable to connect to lldpd daemon
[2023-05-03 18:27:41.191765 ] WARN Facter - invalid or malformed lldp data: MalformedDataError: no lldp interface data found
[2023-05-03 18:27:41.191822 ] DEBUG Facter - /opt/puppetlabs/puppet/cache/lib/facter/lldp.rb:18:in `block (2 levels) in <top (required)>'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/custom_facts/util/resolution.rb:196:in `resolve_value'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/custom_facts/core/resolvable.rb:78:in `block (2 levels) in value'
        /opt/puppetlabs/puppet/lib/ruby/3.2.0/timeout.rb:173:in `timeout'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/custom_facts/core/resolvable.rb:77:in `block in value'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/custom_facts/core/resolvable.rb:102:in `with_timing'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/custom_facts/core/resolvable.rb:76:in `value'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/custom_facts/util/fact.rb:211:in `block in find_first_real_value'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/custom_facts/util/fact.rb:209:in `each'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/custom_facts/util/fact.rb:209:in `find_first_real_value'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/custom_facts/util/fact.rb:131:in `block (2 levels) in value'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/framework/benchmarking/timer.rb:18:in `measure'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/custom_facts/util/fact.rb:130:in `block in value'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/custom_facts/util/fact.rb:177:in `searching'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/custom_facts/util/fact.rb:127:in `value'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/framework/core/fact/external/external_fact_manager.rb:21:in `block in external_facts'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/framework/core/fact/external/external_fact_manager.rb:19:in `each'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/framework/core/fact/external/external_fact_manager.rb:19:in `external_facts'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/framework/core/fact/external/external_fact_manager.rb:7:in `resolve_facts'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/framework/core/fact_manager.rb:24:in `resolve_facts'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter.rb:530:in `resolve_facts_for_user_query'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter.rb:461:in `to_user_output'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/framework/cli/cli.rb:124:in `query'
        /opt/puppetlabs/puppet/lib/ruby/gems/3.2.0/gems/thor-1.2.1/lib/thor/command.rb:27:in `run'
        /opt/puppetlabs/puppet/lib/ruby/gems/3.2.0/gems/thor-1.2.1/lib/thor/invocation.rb:127:in `invoke_command'
        /opt/puppetlabs/puppet/lib/ruby/gems/3.2.0/gems/thor-1.2.1/lib/thor.rb:392:in `dispatch'
        /opt/puppetlabs/puppet/lib/ruby/gems/3.2.0/gems/thor-1.2.1/lib/thor/base.rb:485:in `start'
        /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/facter/framework/cli/cli_launcher.rb:23:in `start'
        /opt/puppetlabs/puppet/bin/facter:10:in `<main>'
...

What do you expect?

If I understand https://www.puppet.com/docs/puppet/8/custom_facts.html correctly failing to resolve lldp shouldn't return warning, but nil in case lldpd daemon is not running.

If the fact fails to resolve or is not present, Facter returns nil.

If it should keep returning warning (e.g. for compatibility) it should return (a substring of) lldpctl's actual warnings :

# /sbin/lldpctl -f json
2023-05-03T18:28:31 [WARN/control] unable to connect to socket /run/lldpd/lldpd.socket: No such file or directory
2023-05-03T18:28:31 [WARN/lldpctl] not able to get the list of interfaces. Unable to connect to lldpd daemon
{
  "lldp": {

  }
}

[kBite]

#153 adds a confine statement effectively returning nil in case lldpd is not running