Manually adding mirror to CentOS gives a new error (still 500 internal server error)

2016-09-27T11:57:40 [app] [W] Action failed
 | ActiveRecord::RecordInvalid: Validation failed: Name must not include periods
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activerecord-4.2.6/lib/active_record/validations.rb:79:in `raise_record_invalid'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activerecord-4.2.6/lib/active_record/validations.rb:43:in `save!'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activerecord-4.2.6/lib/active_record/attribute_methods/dirty.rb:29:in `save!'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activerecord-4.2.6/lib/active_record/transactions.rb:291:in `block in save!'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activerecord-4.2.6/lib/active_record/transactions.rb:351:in `block in with_transaction_returning_status'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `block in transaction'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/abstract/transaction.rb:184:in `within_new_transaction'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `transaction'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activerecord-4.2.6/lib/active_record/transactions.rb:220:in `transaction'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activerecord-4.2.6/lib/active_record/transactions.rb:348:in `with_transaction_returning_status'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activerecord-4.2.6/lib/active_record/transactions.rb:291:in `save!'
 | /usr/share/foreman/app/models/host/managed.rb:850:in `refresh_global_status!'
 | /usr/share/foreman/app/models/host/managed.rb:859:in `refresh_statuses'
 | /usr/share/foreman/app/services/report_importer.rb:43:in `import'
 | /usr/share/foreman/app/services/report_importer.rb:20:in `import'
 | /usr/share/foreman/app/models/config_report.rb:27:in `import'
 | /usr/share/foreman/app/controllers/api/v2/reports_controller.rb:40:in `create'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_controller/metal/implicit_render.rb:4:in `send_action'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/abstract_controller/base.rb:198:in `process_action'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_controller/metal/rendering.rb:10:in `process_action'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/abstract_controller/callbacks.rb:20:in `block in process_action'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:117:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:555:in `block (2 levels) in compile'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:505:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:498:in `block (2 levels) in around'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:313:in `block (2 levels) in halting'
 | /usr/share/foreman/app/controllers/api/v2/base_controller.rb:152:in `disable_json_root'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:432:in `block in make_lambda'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:312:in `block in halting'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:497:in `block in around'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:505:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:498:in `block (2 levels) in around'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:313:in `block (2 levels) in halting'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/rails-observers-0.1.2/lib/rails/observers/action_controller/caching/sweeping.rb:73:in `around'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:455:in `public_send'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:455:in `block in make_lambda'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:312:in `block in halting'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:497:in `block in around'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:505:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:498:in `block (2 levels) in around'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:313:in `block (2 levels) in halting'
 | /usr/share/foreman/app/controllers/concerns/application_shared.rb:13:in `set_timezone'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:432:in `block in make_lambda'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:312:in `block in halting'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:497:in `block in around'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:505:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:498:in `block (2 levels) in around'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:313:in `block (2 levels) in halting'
 | /usr/share/foreman/app/models/concerns/foreman/thread_session.rb:32:in `clear_thread'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:432:in `block in make_lambda'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:312:in `block in halting'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:497:in `block in around'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:505:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:498:in `block (2 levels) in around'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:313:in `block (2 levels) in halting'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/rails-observers-0.1.2/lib/rails/observers/action_controller/caching/sweeping.rb:73:in `around'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:455:in `public_send'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:455:in `block in make_lambda'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:312:in `block in halting'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:497:in `block in around'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:505:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:92:in `__run_callbacks__'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:778:in `_run_process_action_callbacks'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:81:in `run_callbacks'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/abstract_controller/callbacks.rb:19:in `process_action'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_controller/metal/rescue.rb:29:in `process_action'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_controller/metal/instrumentation.rb:32:in `block in process_action'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/notifications.rb:164:in `block in instrument'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/notifications.rb:164:in `instrument'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_controller/metal/instrumentation.rb:30:in `process_action'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_controller/metal/params_wrapper.rb:250:in `process_action'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activerecord-4.2.6/lib/active_record/railties/controller_runtime.rb:18:in `process_action'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/abstract_controller/base.rb:137:in `process'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionview-4.2.6/lib/action_view/rendering.rb:30:in `process'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_controller/metal.rb:196:in `dispatch'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_controller/metal.rb:237:in `block in action'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/routing/route_set.rb:74:in `dispatch'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/routing/route_set.rb:43:in `serve'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/routing/mapper.rb:49:in `serve'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/journey/router.rb:43:in `block in serve'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/journey/router.rb:30:in `each'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/journey/router.rb:30:in `serve'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/routing/route_set.rb:817:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/apipie-rails-0.3.6/lib/apipie/static_dispatcher.rb:65:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/apipie-rails-0.3.6/lib/apipie/extractor/recorder.rb:132:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/apipie-rails-0.3.6/lib/apipie/middleware/checksum_in_headers.rb:27:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/rack-1.6.4/lib/rack/etag.rb:24:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/rack-1.6.4/lib/rack/conditionalget.rb:38:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/rack-1.6.4/lib/rack/head.rb:13:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/middleware/params_parser.rb:27:in `call'
 | /usr/share/foreman/lib/middleware/catch_json_parse_errors.rb:9:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/middleware/flash.rb:260:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/rack-1.6.4/lib/rack/session/abstract/id.rb:225:in `context'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/rack-1.6.4/lib/rack/session/abstract/id.rb:220:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/middleware/cookies.rb:560:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activerecord-4.2.6/lib/active_record/query_cache.rb:36:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/abstract/connection_pool.rb:653:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:88:in `__run_callbacks__'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:778:in `_run_call_callbacks'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:81:in `run_callbacks'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/middleware/callbacks.rb:27:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/middleware/remote_ip.rb:78:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/railties-4.2.6/lib/rails/rack/logger.rb:38:in `call_app'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/railties-4.2.6/lib/rails/rack/logger.rb:22:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/middleware/request_id.rb:21:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/rack-1.6.4/lib/rack/methodoverride.rb:22:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/rack-1.6.4/lib/rack/runtime.rb:18:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/activesupport-4.2.6/lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/actionpack-4.2.6/lib/action_dispatch/middleware/static.rb:120:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/rack-1.6.4/lib/rack/sendfile.rb:113:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/railties-4.2.6/lib/rails/engine.rb:518:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/railties-4.2.6/lib/rails/application.rb:165:in `call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/railties-4.2.6/lib/rails/railtie.rb:194:in `public_send'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/railties-4.2.6/lib/rails/railtie.rb:194:in `method_missing'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/rack-1.6.4/lib/rack/urlmap.rb:66:in `block in call'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/rack-1.6.4/lib/rack/urlmap.rb:50:in `each'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/rack-1.6.4/lib/rack/urlmap.rb:50:in `call'
 | /usr/lib/ruby/vendor_ruby/phusion_passenger/rack/thread_handler_extension.rb:97:in `process_request'
 | /usr/lib/ruby/vendor_ruby/phusion_passenger/request_handler/thread_handler.rb:160:in `accept_and_process_next_request'
 | /usr/lib/ruby/vendor_ruby/phusion_passenger/request_handler/thread_handler.rb:113:in `main_loop'
 | /usr/lib/ruby/vendor_ruby/phusion_passenger/request_handler.rb:416:in `block (3 levels) in start_threads'
 | /usr/lib/ruby/vendor_ruby/phusion_passenger/utils.rb:113:in `block in create_thread_and_abort_on_exception'
 | /usr/share/foreman/vendor/ruby/2.3.0/gems/logging-2.1.0/lib/logging/diagnostic_context.rb:450:in `block in create_with_logging_context'
2016-09-27T11:57:40 [app] [I]   Rendered api/v2/errors/standard_error.json.rabl within api/v2/layouts/error_layout (0.6ms)
2016-09-27T11:57:40 [app] [I] Completed 500 Internal Server Error in 143ms (Views: 1.5ms | ActiveRecord: 28.4ms)

Why is any of those relevant to the operation "cancel build" ? (The machine has already been built, but because of this issue - it's being rebuilt over and over, as it keeps booting from the network

2016-09-27T11:57:40 [app] [W] Action failed | ActiveRecord::RecordInvalid: Validation failed: Name must not include periods

Hard to say why this one has occurred with the log, it seems likely that the FQDN isn't set correctly - perhaps from fact imports.

Why is any of those relevant to the operation "cancel build" ?

The logs so far haven't been from a cancel build operation, both show report imports ( | /usr/share/foreman/app/controllers/api/v2/reports_controller.rb:40:in `create'). The error, if any, from the build cancellation isn't shown.

Errors importing reports were fixed in #14518, which ignores configuration issues during report imports. Please update to the latest 1.12.x patch release, at least 1.12.2.

Generally though, configuration issues need to be fixed for any state changes on hosts, including build cancellation else validation fails and you'll suffer various other issues.

The strange part is that everything seemed fine when I created the host...

The only reason I found this issue is the fact that it's stuck in an endless provisioning loop - as it seems Foreman never removes the PXE entry from DHCP (E.G what I want cancel build to do)

Upgrading to 1.12.3 gives a different error:

Failed to save: Conflict DNS PTR Records 10.0.0.9/fqdn.sub.com.sub.com already exists

Although GUI consistently shows: "Unable to cancel build"

When editing the same host, there's no record of sub.com being part of the name.

Again, I'm confused as to why this would be related to cancel build?