Add ability to define minimal time between job executions to support multiple corno nodes, so two different nodes will not execute the same job

lib/crono/job.rb

@@ -7,9 +7,10 @@ module Crono
     include Logging
 
     attr_accessor :performer, :period, :last_performed_at,
-                  :next_performed_at, :job_log, :job_logger, :healthy
+                  :next_performed_at, :job_log, :job_logger, :healthy, :execution_interval
 
     def initialize(performer, period)
+      self.execution_interval = 0.minutes
       self.performer, self.period = performer, period
       self.job_log = StringIO.new
       self.job_logger = Logger.new(job_log)
@@ -31,6 +32,8 @@ module Crono
     end
 
     def perform
+      return Thread.new {} if perform_before_interval?
+
       log "Perform #{performer}"
       self.last_performed_at = Time.now
       self.next_performed_at = period.next(since: last_performed_at)
@@ -102,5 +105,9 @@ module Crono
     def model
       @model ||= Crono::CronoJob.find_or_create_by(job_id: job_id)
     end
+
+    def perform_before_interval?
+      self.last_performed_at.present? && self.last_performed_at > execution_interval.ago
+    end
   end
 end

lib/crono/performer_proxy.rb

@@ -7,8 +7,14 @@ module Crono
     end
 
     def every(period, *args)
-      job = Job.new(@performer, Period.new(period, *args))
-      @scheduler.add_job(job)
+      @job = Job.new(@performer, Period.new(period, *args))
+      @scheduler.add_job(@job)
+      self
+    end
+
+    def once_per(execution_interval)
+      @job.execution_interval = execution_interval if @job
+      self
     end
   end
 

lib/crono/version.rb

@@ -1,3 +1,3 @@
 module Crono
-  VERSION = '0.9.0'
+  VERSION = '0.9.1'
 end