Avoid env command in facter plugin

... because it interferes with the capability of core facter utility to
translate command to its full path.

Also override of environment variables is not really necessary when
'mysqd' command is found in PATH.

Signed-off-by: Takashi Kajinami <kajinamit@oss.nttdata.com>

Author: kajinamit

lib/facter/mysqld_version.rb

@@ -2,8 +2,10 @@
 
 Facter.add('mysqld_version') do
   setcode do
-    if Facter::Core::Execution.which('mysqld') || Facter::Core::Execution.which('/usr/libexec/mysqld')
-      Facter::Core::Execution.execute('env PATH=$PATH:/usr/libexec mysqld --no-defaults -V 2>/dev/null')
+    if Facter::Core::Execution.which('mysqld')
+      Facter::Core::Execution.execute('mysqld --no-defaults -V 2>/dev/null')
+    elsif Facter::Core::Execution.which('/usr/libexec/mysqld')
+      Facter::Core::Execution.execute('/usr/libexec/mysqld --no-defaults -V 2>/dev/null')
     elsif Facter::Core::Execution.which('mariadbd')
       Facter::Core::Execution.execute('mariadbd --no-defaults -V 2>/dev/null')
     end

spec/unit/facter/mysqld_version_spec.rb

@@ -11,8 +11,23 @@
     context 'with mysqld' do
       before :each do
         allow(Facter::Core::Execution).to receive(:which).with('mysqld').and_return('/usr/sbin/mysqld')
+        allow(Facter::Core::Execution).to receive(:which).with('/usr/libexec/mysqld').and_return(false)
+        allow(Facter::Core::Execution).to receive(:which).with('mariadbd').and_return(false)
+        allow(Facter::Core::Execution).to receive(:execute).with('mysqld --no-defaults -V 2>/dev/null')
+                                                           .and_return('mysqld  Ver 5.5.49-37.9 for Linux on x86_64 (Percona Server (GPL), Release 37.9, Revision efa0073)')
+      end
+
+      it {
+        expect(Facter.fact(:mysqld_version).value).to eq('mysqld  Ver 5.5.49-37.9 for Linux on x86_64 (Percona Server (GPL), Release 37.9, Revision efa0073)')
+      }
+    end
+
+    context 'with mysqld in /usr/libexec/mysqld' do
+      before :each do
+        allow(Facter::Core::Execution).to receive(:which).with('mysqld').and_return(false)
+        allow(Facter::Core::Execution).to receive(:which).with('/usr/libexec/mysqld').and_return('/usr/libexec/mysqld')
         allow(Facter::Core::Execution).to receive(:which).with('mariadbd').and_return(false)
-        allow(Facter::Core::Execution).to receive(:execute).with('env PATH=$PATH:/usr/libexec mysqld --no-defaults -V 2>/dev/null')
+        allow(Facter::Core::Execution).to receive(:execute).with('/usr/libexec/mysqld --no-defaults -V 2>/dev/null')
                                                            .and_return('mysqld  Ver 5.5.49-37.9 for Linux on x86_64 (Percona Server (GPL), Release 37.9, Revision efa0073)')
       end