Ensure that we check the embedded gem binary lasttm/gem_path

Previously we injected our expected paths in to ENV['PATH'] but we
stopped doing that in Chef 13; for gem_package, we need to ensure that
if all else fails we'll use the Omnibus provided gem binary, but we
should never pick that if we can find a different one.

Closes: #6103
Signed-off-by: Thom May <thom@chef.io>

3 files changed, 18 insertions, 17 deletions

diff --git a/lib/chef/mixin/which.rb b/lib/chef/mixin/which.rb
index fd386241a0..8a825f55c9 100644
--- a/lib/chef/mixin/which.rb
+++ b/lib/chef/mixin/which.rb
@@ -25,7 +25,7 @@ class Chef
       def where(*cmds, extra_path: nil, &block)
         # NOTE: unnecessarily duplicates function of path_sanity
         extra_path ||= [ "/bin", "/usr/bin", "/sbin", "/usr/sbin" ]
-        paths = env_path.split(File::PATH_SEPARATOR) + extra_path
+        paths = env_path.split(File::PATH_SEPARATOR) + Array(extra_path)
         cmds.map do |cmd|
           paths.map do |path|
             filename = Chef.path_to(File.join(path, cmd))
diff --git a/lib/chef/provider/package/rubygems.rb b/lib/chef/provider/package/rubygems.rb
index 69936b3d58..161f790c31 100644
--- a/lib/chef/provider/package/rubygems.rb
+++ b/lib/chef/provider/package/rubygems.rb
@@ -21,6 +21,7 @@ require "uri"
 require "chef/provider/package"
 require "chef/resource/package"
 require "chef/mixin/get_source_from_package"
+require "chef/mixin/which"
 
 # Class methods on Gem are defined in rubygems
 require "rubygems"
@@ -359,6 +360,7 @@ class Chef
         provides :gem_package
 
         include Chef::Mixin::GetSourceFromPackage
+        include Chef::Mixin::Which
 
         def initialize(new_resource, run_context = nil)
           super
@@ -410,11 +412,7 @@ class Chef
         end
 
         def find_gem_by_path
-          Chef::Log.debug("#{new_resource} searching for 'gem' binary in path: #{ENV['PATH']}")
-          separator = ::File::ALT_SEPARATOR ? ::File::ALT_SEPARATOR : ::File::SEPARATOR
-          path_to_first_gem = ENV["PATH"].split(::File::PATH_SEPARATOR).find { |path| ::File.exist?(path + separator + "gem") }
-          raise Chef::Exceptions::FileNotFound, "Unable to find 'gem' binary in path: #{ENV['PATH']}" if path_to_first_gem.nil?
-          path_to_first_gem + separator + "gem"
+          which("gem", extra_path: RbConfig::CONFIG["bindir"])
         end
 
         def gem_dependency
diff --git a/spec/unit/provider/package/rubygems_spec.rb b/spec/unit/provider/package/rubygems_spec.rb
index c40eed50cf..9f19e3602f 100644
--- a/spec/unit/provider/package/rubygems_spec.rb
+++ b/spec/unit/provider/package/rubygems_spec.rb
@@ -338,7 +338,7 @@ describe Chef::Provider::Package::Rubygems do
   let(:target_version) { nil }
   let(:gem_name) { "rspec-core" }
   let(:gem_binary) { nil }
-  let(:bindir) { "/usr/bin/ruby" }
+  let(:bindir) { "/usr/bin" }
   let(:options) { nil }
   let(:source) { nil }
   let(:include_default_source) { true }
@@ -372,6 +372,8 @@ describe Chef::Provider::Package::Rubygems do
     allow(RbConfig::CONFIG).to receive(:[]).with("bindir").and_return(bindir)
     # Rubygems uses this interally
     allow(RbConfig::CONFIG).to receive(:[]).with("arch").and_call_original
+    allow(File).to receive(:executable?).and_return false
+    allow(File).to receive(:executable?).with("#{bindir}/gem").and_return true
   end
 
   describe "when new_resource version is nil" do
@@ -439,9 +441,9 @@ describe Chef::Provider::Package::Rubygems do
       it "searches for a gem binary when running on Omnibus on Unix" do
         platform_mock :unix do
           allow(ENV).to receive(:[]).with("PATH").and_return("/usr/bin:/usr/sbin:/opt/chef/embedded/bin")
-          allow(File).to receive(:exist?).with("/usr/bin/gem").and_return(false)
-          allow(File).to receive(:exist?).with("/usr/sbin/gem").and_return(true)
-          allow(File).to receive(:exist?).with("/opt/chef/embedded/bin/gem").and_return(true) # should not get here
+          allow(File).to receive(:executable?).with("/usr/bin/gem").and_return(false)
+          allow(File).to receive(:executable?).with("/usr/sbin/gem").and_return(true)
+          allow(File).to receive(:executable?).with("/opt/chef/embedded/bin/gem").and_return(true) # should not get here
           expect(provider.gem_env.gem_binary_location).to eq("/usr/sbin/gem")
         end
       end
@@ -451,13 +453,14 @@ describe Chef::Provider::Package::Rubygems do
 
         it "searches for a gem binary when running on Omnibus on Windows" do
           platform_mock :windows do
-            allow(ENV).to receive(:[]).with("PATH").and_return('C:\windows\system32;C:\windows;C:\Ruby186\bin;d:\opscode\chef\embedded\bin')
-            allow(File).to receive(:exist?).with('C:\\windows\\system32\\gem').and_return(false)
-            allow(File).to receive(:exist?).with('C:\\windows\\gem').and_return(false)
-            allow(File).to receive(:exist?).with('C:\\Ruby186\\bin\\gem').and_return(true)
-            allow(File).to receive(:exist?).with('d:\\opscode\\chef\\bin\\gem').and_return(false) # should not get here
-            allow(File).to receive(:exist?).with('d:\\opscode\\chef\\embedded\\bin\\gem').and_return(false) # should not get here
-            expect(provider.gem_env.gem_binary_location).to eq('C:\Ruby186\bin\gem')
+            allow(ENV).to receive(:[]).with("PATH").and_return('C:\windows\system32;C:\windows;C:\Ruby186\bin')
+            allow(File).to receive(:executable?).with('C:\\windows\\system32/gem').and_return(false)
+            allow(File).to receive(:executable?).with('C:\\windows/gem').and_return(false)
+            allow(File).to receive(:executable?).with('C:\\Ruby186\\bin/gem').and_return(true)
+            allow(File).to receive(:executable?).with('d:\\opscode\\chef\\bin/gem').and_return(false) # should not get here
+            allow(File).to receive(:executable?).with('d:\\opscode\\chef\\bin/gem').and_return(false) # should not get here
+            allow(File).to receive(:executable?).with("d:/opscode/chef/embedded/bin/gem").and_return(false) # should not get here
+            expect(provider.gem_env.gem_binary_location).to eq('C:\Ruby186\bin/gem')
           end
         end
       end