allow forcing crystal ball to run despite config changes

refs DE-1220

Change-Id: I12d3e9b4728e94c816a6bf610345aedf18c1baa7
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/303477
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: James Butters <jbutters@instructure.com>
Build-Review: James Butters <jbutters@instructure.com>
QA-Review: Aaron Ogata <aogata@instructure.com>
Product-Review: Aaron Ogata <aogata@instructure.com>

Jenkinsfile

@@ -279,6 +279,8 @@ pipeline {
     NODE = configuration.node()
     RUBY = configuration.ruby() // RUBY_VERSION is a reserved keyword for ruby installs
 
+    FORCE_CRYSTALBALL = "${configuration.getBoolean('force-crystalball', '0') ? 1 : 0}"
+
     BASE_RUNNER_PREFIX = configuration.buildRegistryPath('base-runner')
     CASSANDRA_PREFIX = configuration.buildRegistryPath('cassandra-migrations')
     DYNAMODB_PREFIX = configuration.buildRegistryPath('dynamodb-migrations')
@@ -457,6 +459,7 @@ pipeline {
                                         -e CRYSTALBALL_DIFF_FROM=$diffFrom \
                                         -e CRYSTALBALL_DIFF_TO=$GERRIT_PATCHSET_REVISION \
                                         -e CRYSTALBALL_REPO_PATH=$DOCKER_WORKDIR \
+                                        -e FORCE_CRYSTALBALL=$FORCE_CRYSTALBALL \
                                         general-build-container bundle exec crystalball --dry-run
                       '''
 

spec/support/crystalball.rb

@@ -198,7 +198,10 @@ module Crystalball
             change_map[change_type] << change_path
           end
           Crystalball.log :warn, "Crystalball changes: #{file_changes.slice("new", "modified")}"
-          if file_changes["new"].count.positive?
+          if ENV["FORCE_CRYSTALBALL"] == "1"
+            Crystalball.log :warn, "Crystalball force enabled despite config changes or new files"
+            []
+          elsif file_changes["new"].count.positive?
             Crystalball.log :warn, "Crystalball detected new .git files: #{file_changes["new"]}"
             Crystalball.log :warn, "Crystalball requesting entire suite re-run"
             ["."]