Avoid accidentally reusing a gid in testsbtm/func-group-gid

Some platforms have groups in odd ranges, make sure the gid we select is
not in use.

Signed-off-by: Bryan McLellan <btm@loftninjas.org>

1 files changed, 10 insertions, 1 deletions

diff --git a/spec/functional/resource/group_spec.rb b/spec/functional/resource/group_spec.rb
index 94f00185c4..bcea91c1d5 100644
--- a/spec/functional/resource/group_spec.rb
+++ b/spec/functional/resource/group_spec.rb
@@ -292,7 +292,16 @@ describe Chef::Resource::Group, :requires_root_or_running_windows do
     end
   end
 
-  let(:number) { rand(2000..9999) } # avoid low group numbers
+  let(:number) do
+    # Loop until we pick a gid that is not in use.
+    loop do
+      gid = rand(2000..9999) # avoid low group numbers
+      return nil if Etc.getgrgid(gid).nil? # returns nil on windows
+    rescue ArgumentError # group does not exist
+      return gid
+    end
+  end
+
   let(:group_name) { "grp#{number}" } # group name should be 8 characters or less for Solaris, and possibly others
   # https://community.aegirproject.org/developing/architecture/unix-group-limitations/index.html#Group_name_length_limits
   let(:included_members) { [] }