Add more OkComputer checks

.travis.yml

@@ -17,3 +17,6 @@ cache: bundler
 
 rvm:
   - 2.4.4
+
+services:
+  - redis-server

config/initializers/okcomputer.rb

@@ -1,3 +1,42 @@
 # by default, okcomputer does "app up?" and "database conntected?" checks
 OkComputer.mount_at = 'status' # use /status or /status/all or /status/<name-of-check>
 OkComputer.check_in_parallel = true
+
+OkComputer::Registry.register 'ruby_version', OkComputer::RubyVersionCheck.new
+
+# check whether resque workers are working
+OkComputer::Registry.register 'feature-resque-down', OkComputer::ResqueDownCheck.new
+
+# check for backed up resque queues: this is a low volume app, so the threshold is low
+Resque.queues.each do |queue|
+  OkComputer::Registry.register "feature-#{queue}-queue-depth", OkComputer::ResqueBackedUpCheck.new(queue, 5)
+end
+
+class DirectoryExistsCheck < OkComputer::Check
+  attr_accessor :directory
+
+  def initialize(directory)
+    self.directory = directory
+  end
+
+  def check
+    stat = File.stat(directory) if File.exist?(directory)
+    if stat
+      if stat.directory?
+        mark_message "'#{directory}' is a reachable directory"
+      else
+        mark_message "'#{directory}' is not a directory."
+        mark_failure
+      end
+    else
+      mark_message "Directory '#{directory}' does not exist."
+      mark_failure
+    end
+  end
+end
+
+# Confirm job_output_parent_dir exists (or else jobs cannot output)
+OkComputer::Registry.register 'feature-job_output_parent_dir', DirectoryExistsCheck.new(Settings.job_output_parent_dir)
+
+# To make checks optional:
+# OkComputer.make_optional %w[feature-resque-down]