Wrap in a transaction, rollback on dry-run or error

https://bugzilla.redhat.com/show_bug.cgi?id=1590908

tools/remove_grouping_from_report_results.rb

@@ -18,9 +18,11 @@
 # Load rails after trollop options are set.  No one wants to wait for -h.
 require File.expand_path('../config/environment', __dir__)
 
+# Wrap all changes in a transaction and roll them back if dry-run or an error occurs.
+ActiveRecord::Base.connection.begin_transaction(:joinable => false)
+
 if opts[:dry_run]
-  puts "Running in dry-run, changes will be rolled back when complete."
-  ActiveRecord::Base.connection.begin_transaction(:joinable => false)
+  puts "Running in dry-run, all changes will be rolled back when complete."
 
   at_exit do
     ActiveRecord::Base.connection.rollback_transaction
@@ -30,23 +32,32 @@
 start = Time.now.utc
 total = 0
 fixed = 0
+
 MiqReportResult.find_each(:batch_size => opts[:batch_size]).with_index do |rr, i|
-  break if opts[:count].positive? && i == opts[:count]
-  next if rr.report.nil? || rr.report.extras.nil?
-
-  if rr.report.extras.key?(:grouping)
-    rr.report.extras.except!(:grouping)
-    rr.save!
-    if rr.reload.report.extras.key?(:grouping)
-      puts "MiqReportResult: #{rr.id} could NOT be fixed"
+  begin
+    break if opts[:count].positive? && i == opts[:count]
+    next if rr.report.nil? || rr.report.extras.nil?
+
+    if rr.report.extras.key?(:grouping)
+      rr.report.extras.except!(:grouping)
+      rr.save!
+      if rr.reload.report.extras.key?(:grouping)
+        puts "MiqReportResult: #{rr.id} could NOT be fixed"
+      else
+        puts "MiqReportResult: #{rr.id} fixed"
+        fixed += 1
+      end
     else
-      puts "MiqReportResult: #{rr.id} fixed"
-      fixed += 1
+      puts "MiqReportResult: #{rr.id} doesn't need fixing"
     end
-  else
-    puts "MiqReportResult: #{rr.id} doesn't need fixing"
+
+    total += 1
+  rescue => err
+    puts "\nWarning: Rolling back all changes since an error occurred on MiqReportResult with id: #{rr.try(:id)}: #{err.message}"
+    ActiveRecord::Base.connection.rollback_transaction unless opts[:dry_run]
+    exit 1
   end
-  total += 1
 end
 
-puts "Processed #{total} rows. #{fixed} were fixed. #{Time.now.utc - start} seconds"
+ActiveRecord::Base.connection.commit_transaction unless opts[:dry_run]
+puts "\nProcessed #{total} rows. #{fixed} were fixed. #{Time.now.utc - start} seconds"