Silence verify_host_key warning from net-ssh

lib/train/transports/ssh.rb

@@ -167,9 +167,9 @@ def connection_options(opts)
         non_interactive:        opts[:non_interactive],
         transport_options:      opts,
       }
-      # disable host key verification. The hash key to use
+      # disable host key verification. The hash key and value to use
       # depends on the version of net-ssh in use.
-      connection_options[verify_host_key_option] = opts[:verify_host_key] || false
+      connection_options[verify_host_key_option] = verify_host_key_value(opts[:verify_host_key])
 
       connection_options
     end
@@ -193,6 +193,35 @@ def verify_host_key_option
       current_net_ssh >= new_option_version ? :verify_host_key : :paranoid
     end
 
+    # Likewise, version <5 accepted false; 5+ requires :never or will
+    # issue a deprecation warning. This method allows a lot of common
+    # things through.
+    def verify_host_key_value(given)
+      current_net_ssh = Net::SSH::Version::CURRENT
+      new_value_version = Net::SSH::Version[5, 0, 0]
+      if current_net_ssh >= new_value_version
+        # 5.0+ style
+        {
+          # It's not a boolean anymore.
+          'true' => :always,
+          'false' => :never,
+          true => :always,
+          false => :never,
+          # May be correct value, but strings from JSON config
+          'always' => :always,
+          'never' => :never,
+          nil => :never,
+        }.fetch(given, given)
+      else
+        # up to 4.2 style
+        {
+          'true' => true,
+          'false' => false,
+          nil => false,
+        }.fetch(given, given)
+      end
+    end
+
     # Creates a new SSH Connection instance and save it for potential future
     # reuse.
     #

test/unit/helper.rb

@@ -2,6 +2,7 @@
 
 require 'minitest/autorun'
 require 'minitest/spec'
+require 'mocha/minitest'
 require 'mocha/setup'
 require 'byebug'
 

test/unit/transports/ssh_test.rb

@@ -1,6 +1,6 @@
 # encoding: utf-8
 
-require 'helper'
+require_relative '../helper'
 require 'train/transports/ssh'
 
 describe 'ssh transport' do
@@ -62,6 +62,42 @@
         connection_options[:verify_host_key].must_equal true
       end
     end
+
+    describe "various values are mapped appropriately for verify_host_key" do
+      # This would be better:
+      # Net::SSH::Version.stub_const(:CURRENT, Net::SSH::Version[5,0,1])
+      current_version = Net::SSH::Version::CURRENT
+      threshold_version = Net::SSH::Version[5, 0, 0]
+      if current_version < threshold_version
+        it "maps correctly when net-ssh < 5.0" do
+          {
+            'true' => true,
+            'false' => false,
+            nil => false,
+          }.each do |given, expected|
+            opts = { :verify_host_key => given }
+            seen_opts = ssh.send(:connection_options, opts)
+            seen_opts[:verify_host_key].must_equal expected
+          end
+        end
+      else
+        it "maps correctly when net-ssh > 5.0" do
+          {
+            'true' => :always,
+            'false' => :never,
+            true => :always,
+            false => :never,
+            'always' => :always,
+            'never' => :never,
+            nil => :never,
+          }.each do |given, expected|
+            opts = { :verify_host_key => given }
+            seen_opts = ssh.send(:connection_options, opts)
+            seen_opts[:verify_host_key].must_equal expected
+          end
+        end
+      end
+    end
   end
 
   describe 'ssh options' do