be_reacheable matcher for host resource should not always use ping on linux

[scboucher]

Description

host resource always use ping on linux. When the proto is set to tcp or udp it should at least warning the use it is going to use ping instead.

See also #1439

InSpec and Platform Version

inspec --version
1.14.1
linux debian

Replication Case

Here is an example of control that

control 'server-1.0' do
  impact 1.0
  title 'Access to my server'
  desc 'builders should be able to access my server'
  describe host('www.example.com', port: 443, proto: 'tcp') do
    it { should be_reachable }
  end
end

Possible Solutions

host could use netcat when proto is 'tcp' or 'udp'
tcp

nc -v -w 1 example.com 443

or
udp

nc -v -u -w3 example.com 53

Stacktrace

D, [2017-02-22T19:26:24.014917 #9326] DEBUG -- : [SSH] myuser@example.com<{:user_known_hosts_file=>"/dev/null", :paranoid=>false, :port=>22, :compression=>false, :compression_level=>0, :keepalive=>true, :keepalive_interval=>60, :timeout=>15, :auth_methods=>["none", "publickey"], :keys_only=>nil, :keys=>nil, :forward_agent=>nil, :logger=>#<Logger:0x007f9dc6a56e30 @progname=nil, @level=4, @default_formatter=#<Logger::Formatter:0x007f9dc6a56bd8 @datetime_format=nil>, @formatter=nil, @logdev=#<Logger::LogDevice:0x007f9dc6a56b60 @shift_size=nil, @shift_age=nil, @filename=nil, @dev=#<IO:<STDERR>>, @mutex=#<Logger::LogDevice::LogDeviceMutex:0x007f9dc6a56ae8 @mon_owner=nil, @mon_count=0, @mon_mutex=#<Mutex:0x007f9dc6a569a8>>>>, :password_prompt=>#<Net::SSH::Prompt:0x007f9dc6a568e0>, :user=>"myuser"}> (ping -w 1 -c 1 exemple.com)

[adamleff]

@scboucher Thanks for submitting this issue! It does appear we could offer better transparency and better functionality here.

Since this enhancement is already requested in #1439 as you've indicated, I'm going to close this issue as a duplicate of that one. Please feel free to subscribe to that one for further updates. In addition, as a friendly reminder, Pull Requests are always welcome. 😄

Thanks again for reaching out!