Fix RedHat acceptance tests

Ensure we install nginx from the default repo: cleanup leftovers from
previous tests and skip repo management when testing nginx mail features
(sic).

Also, do not try to test passenger support on CentOS Stream which has no
support for it.

spec/acceptance/class_spec.rb

@@ -8,6 +8,12 @@
     pkg_cmd = 'yum info nginx | grep "^From repo"'
     pkg_remove_cmd = 'yum -y remove nginx nginx-filesystem passenger'
     pkg_match = case fact('operatingsystemmajrelease')
+                when '8'
+                  # Erf, CentOS 8 package nginx and passenger in appstream, but
+                  # has no support for passenger-nginx
+                  pkg_cmd = false
+
+                  %r{appstream}
                 when '7' # https://blog.phusion.nl/2020/05/29/passenger-6-0-5/
                   %r{epel}
                 else

spec/acceptance/nginx_mail_spec.rb

@@ -3,16 +3,39 @@
 require 'spec_helper_acceptance'
 
 describe 'nginx::resource::mailhost define:' do
+  it 'remove leftovers from previous tests' do
+    # The following breaks on CentOS Stream, but this workaround is only
+    # required for older versions of CentOS so we can ignore it.
+    pp = "
+    if fact('os.family') == 'RedHat' and versioncmp(fact('os.release.full'), '8.0') < 0 {
+      yumrepo { 'nginx-release':
+        ensure => absent,
+      }
+      yumrepo { 'passenger':
+        ensure => absent,
+      }
+      package { 'nginx':
+        ensure => absent,
+      }
+    }
+    "
+    apply_manifest(pp, catch_failures: true)
+  end
+
   it 'runs successfully' do
     pp = "
     if fact('os.family') == 'RedHat' {
       package { 'nginx-mod-mail':
         ensure => installed,
       }
+      $manage_repo = false
+    } else {
+      $manage_repo = true
     }
 
     class { 'nginx':
       mail            => true,
+      manage_repo     => $manage_repo,
       dynamic_modules => fact('os.family') ? {
         'RedHat' => ['/usr/lib64/nginx/modules/ngx_mail_module.so'],
         default  => [],
@@ -32,6 +55,10 @@ class { 'nginx':
     "
 
     apply_manifest(pp, catch_failures: true)
+    # The module produce different config when nginx is installed and when it
+    # is not installed prior to getting facts, so we need to re-apply the
+    # catalog.
+    apply_manifest(pp, catch_failures: true)
   end
 
   describe file('/etc/nginx/conf.mail.d/domain1.example.conf') do