First draft of running the I18n Sync Down & Out periodically throughout the week.

bin/i18n/sync-all.rb

@@ -40,14 +40,14 @@ def initialize(args)
 
   def run
     if @options[:interactive]
-      checkout_staging
+      return_to_staging_branch
       sync_in if should_i "sync in"
       sync_up if should_i "sync up"
       CreateI18nPullRequests.in_and_up if @options[:with_pull_request] && should_i("create the in & up PR")
       sync_down if should_i "sync down"
       sync_out(true) if should_i "sync out"
       CreateI18nPullRequests.down_and_out if @options[:with_pull_request] && should_i("create the down & out PR")
-      checkout_staging
+      return_to_staging_branch
     elsif @options[:command]
       case @options[:command]
       when 'in'
@@ -136,8 +136,21 @@ def should_i(question)
     end
   end
 
-  def checkout_staging
-    return if GitUtils.current_branch == "staging"
+  def return_to_staging_branch
+    case GitUtils.current_branch
+    when "staging"
+      # If we're already on staging, we don't need to bother
+      return
+    when /^i18n-sync/
+      # If we're on an i18n sync branch, only return to staging if the branch
+      # has been merged.
+      return unless GitUtils.current_branch_merged_into? "staging"
+    else
+      # If we're on some other branch, then we're in some kind of weird state,
+      # so error out.
+      raise "Tried to return to staging branch from unknown branch #{GitUtils.current_branch.inspect}"
+    end
+
     `git checkout staging` if should_i "switch to staging branch"
   end
 end

experimental/i18n-dev.crontab

@@ -19,9 +19,25 @@
 PATH=/home/ubuntu/.rbenv/shims:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
 HOME=/home/ubuntu
 
+# Run a CI Build to update the server from staging. We do this primarily to
+# make sure the server gets seeded with latest level content for the sync in.
+# Note that the CI_ONLY_BUILD environment variable is necessary; the server is
+# not set up to actually serve a version of the website, and it will fail to
+# build correctly if not thus restricted.
 0 */4 * * * cd /home/ubuntu/code-dot-org && CI_ONLY_BUILD=true bundle exec ./bin/cronjob ./aws/ci_build >>/tmp/cronlog 2>&1
 
+# Run the I18n Sync!
 # Sync is scheduled for 12:30 AM PST every Monday; run around midnight so the
 # sync is hopefully finished by start of day on Monday, offset by 30 minutes so
 # we don't conflict with the ci_build which runs on the hour.
-30 8 * * 1 (cd /home/ubuntu/code-dot-org && (bundle exec ./bin/i18n/sync-all.rb -yip | ./bin/i18n/slack_log) 2>&1 | ./bin/i18n/slack_error) >>/tmp/cronlog 2>&1
+30 8 * * MON (cd /home/ubuntu/code-dot-org && (bundle exec ./bin/i18n/sync-all.rb -yip | ./bin/i18n/slack_log) 2>&1 | ./bin/i18n/slack_error) >>/tmp/cronlog 2>&1
+
+# Run the sync down periodically throughout the week. Specifically:
+# - Run it every other hour. This is a somewhat arbitrarily-chosen frequency
+#   for a test period. We expect to refine this over time.
+# - Run it on the half-hour. Like for the full sync, this is done to reduce the
+#   chance of colliding with the CI Build.
+# - Run it every day except Monday. This is done so we don't conflict with the
+#   full sync, and also because we expect to spend Monday verifiying the
+#   results of the full sync.
+30 */2 * * SUN,TUE-SAT cd /home/ubuntu/code-dot-org && ((bundle exec ./bin/i18n/sync-all -c down && bundle exec ./bin/i18n/sync-all -c out) | ./bin/i18n/slack_log) 2>&1 | ./bin/i18n/slack_error

lib/cdo/git_utils.rb

@@ -50,6 +50,23 @@ def self.current_branch
     `git rev-parse --abbrev-ref HEAD`.strip
   end
 
+  # Get a list of the names of all branches merged into the given branch
+  def self.merged_branches(base_branch)
+    merged_branches = `git branch --merged #{base_branch}`.split("\n")
+    merged_branches.each do |branch|
+      # The return format here is a bit messy, so in addition to splitting by
+      # newline to turn it into a list we also want to make sure to clean up
+      # whitespace and the "* " string used to denote the current branch.
+      branch.strip!
+      branch.delete_prefix! "* "
+    end
+    return merged_branches
+  end
+
+  def self.current_branch_merged_into?(base_branch)
+    merged_branches(base_branch).include? current_branch
+  end
+
   def self.get_latest_commit_merged_branch
     get_branch_commit_merges(git_revision)
   end

lib/test/cdo/test_git_utils.rb

@@ -31,4 +31,23 @@ def test_dashboard_globs
     )
     assert_equal 0, files.length, 'ignores files in dashboard/test/ui'
   end
+
+  def test_current_branch_merged_into
+    GitUtils.stubs(:current_branch).returns("current_branch")
+    GitUtils.stubs(:merged_branches).returns(
+      %w(
+        staging
+        some_other_branch
+      )
+    )
+    refute GitUtils.current_branch_merged_into?("staging")
+    GitUtils.stubs(:merged_branches).returns(
+      %w(
+        staging
+        current_branch
+        some_other_branch
+      )
+    )
+    assert GitUtils.current_branch_merged_into?("staging")
+  end
 end