Hi,

during the upgrade from Katello 3.4 to 3.5 I noticed that the Upgrade automatically enabled the DNS Proxy in my Foreman Host.
This caused the installer to fail with the following Stacktrace:

Proxy <redacted> has failed to load one or more features (DNS), check /var/log/foreman-proxy/proxy.log for configuration errors
/usr/share/foreman-installer/modules/foreman/lib/puppet/provider/foreman_smartproxy/rest_v3.rb:70:in `validate_features!'
/usr/share/foreman-installer/modules/foreman/lib/puppet/provider/foreman_smartproxy/rest_v3.rb:59:in `refresh_features!'
/usr/share/foreman-installer/modules/foreman/lib/puppet/provider/foreman_smartproxy/rest_v3.rb:48:in `features='
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/property.rb:194:in `call_provider'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/property.rb:501:in `set'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/property.rb:561:in `sync'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction/resource_harness.rb:236:in `sync'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction/resource_harness.rb:134:in `sync_if_needed'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction/resource_harness.rb:88:in `block in perform_changes'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction/resource_harness.rb:87:in `each'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction/resource_harness.rb:87:in `perform_changes'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction/resource_harness.rb:21:in `evaluate'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction.rb:230:in `apply'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction.rb:246:in `eval_resource'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction.rb:163:in `call'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction.rb:163:in `block (2 levels) in evaluate'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/util.rb:507:in `block in thinmark'
/opt/puppetlabs/puppet/lib/ruby/2.1.0/benchmark.rb:294:in `realtime'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/util.rb:506:in `thinmark'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction.rb:163:in `block in evaluate'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/graph/relationship_graph.rb:118:in `traverse'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction.rb:154:in `evaluate'
/usr/share/gems/gems/kafo-2.0.1/modules/kafo_configure/lib/puppet/parser/functions/add_progress.rb:30:in `evaluate_with_trigger'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/resource/catalog.rb:222:in `block in apply'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/util/log.rb:155:in `with_destination'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction/report.rb:142:in `as_logging_destination'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/resource/catalog.rb:221:in `apply'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/configurer.rb:171:in `block in apply_catalog'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/util.rb:224:in `block in benchmark'
/opt/puppetlabs/puppet/lib/ruby/2.1.0/benchmark.rb:294:in `realtime'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/util.rb:223:in `benchmark'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/configurer.rb:170:in `apply_catalog'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/configurer.rb:343:in `run_internal'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/configurer.rb:221:in `block in run'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/context.rb:65:in `override'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet.rb:306:in `override'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/configurer.rb:195:in `run'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/application/apply.rb:350:in `apply_catalog'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/application/apply.rb:274:in `block in main'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/context.rb:65:in `override'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet.rb:306:in `override'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/application/apply.rb:225:in `main'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/application/apply.rb:170:in `run_command'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/application.rb:358:in `block in run'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/util.rb:662:in `exit_on_fail'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/application.rb:358:in `run'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/util/command_line.rb:132:in `run'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/util/command_line.rb:72:in `execute'
/opt/puppetlabs/puppet/bin/puppet:5:in `<main>'
/Stage[main]/Foreman_proxy::Register/Foreman_smartproxy[<redacted>]/features: change from ["DHCP", "Dynflow", "Pulp", "Puppet", "Puppet CA", "SSH", "TFTP", "Templates"] to ["DHCP", "DNS", "Dynflow", "Puppet", "Puppet CA", "TFTP", "Templates"] failed: Proxy <redacted> has failed to load one or more features (DNS), check /var/log/foreman-proxy/proxy.log for configuration errors
/Stage[main]/Foreman_proxy::Register/Foreman_smartproxy[<redacted>]: Failed to call refresh: Proxy <redacted> has failed to load one or more features (DNS), check /var/log/foreman-proxy/proxy.log for configuration errors
/Stage[main]/Foreman_proxy::Register/Foreman_smartproxy[<redacted>]: Proxy <redacted> has failed to load one or more features (DNS), check /var/log/foreman-proxy/proxy.log for configuration errors
/usr/share/foreman-installer/modules/foreman/lib/puppet/provider/foreman_smartproxy/rest_v3.rb:70:in `validate_features!'
/usr/share/foreman-installer/modules/foreman/lib/puppet/provider/foreman_smartproxy/rest_v3.rb:59:in `refresh_features!'
/usr/share/foreman-installer/modules/foreman/lib/puppet/type/foreman_smartproxy.rb:73:in `refresh'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction/event_manager.rb:147:in `process_callback'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction/event_manager.rb:34:in `block in process_events'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction/event_manager.rb:119:in `block in queued_events'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction/event_manager.rb:118:in `each'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction/event_manager.rb:118:in `queued_events'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction/event_manager.rb:33:in `process_events'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction.rb:247:in `eval_resource'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction.rb:163:in `call'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction.rb:163:in `block (2 levels) in evaluate'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/util.rb:507:in `block in thinmark'
/opt/puppetlabs/puppet/lib/ruby/2.1.0/benchmark.rb:294:in `realtime'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/util.rb:506:in `thinmark'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction.rb:163:in `block in evaluate'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/graph/relationship_graph.rb:118:in `traverse'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction.rb:154:in `evaluate'
/usr/share/gems/gems/kafo-2.0.1/modules/kafo_configure/lib/puppet/parser/functions/add_progress.rb:30:in `evaluate_with_trigger'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/resource/catalog.rb:222:in `block in apply'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/util/log.rb:155:in `with_destination'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/transaction/report.rb:142:in `as_logging_destination'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/resource/catalog.rb:221:in `apply'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/configurer.rb:171:in `block in apply_catalog'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/util.rb:224:in `block in benchmark'
/opt/puppetlabs/puppet/lib/ruby/2.1.0/benchmark.rb:294:in `realtime'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/util.rb:223:in `benchmark'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/configurer.rb:170:in `apply_catalog'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/configurer.rb:343:in `run_internal'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/configurer.rb:221:in `block in run'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/context.rb:65:in `override'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet.rb:306:in `override'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/configurer.rb:195:in `run'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/application/apply.rb:350:in `apply_catalog'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/application/apply.rb:274:in `block in main'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/context.rb:65:in `override'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet.rb:306:in `override'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/application/apply.rb:225:in `main'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/application/apply.rb:170:in `run_command'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/application.rb:358:in `block in run'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/util.rb:662:in `exit_on_fail'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/application.rb:358:in `run'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/util/command_line.rb:132:in `run'
/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/util/command_line.rb:72:in `execute'
/opt/puppetlabs/puppet/bin/puppet:5:in `<main>'

I could work around this by calling foreman-installer with "--foreman-proxy-dns false", but I would expect the installer to keep the current configuration.