(PUP-12061) Log when periodic agent runs

Provide more context when the agent runs so it's clearer whether splay is
enabled and what the limits are. We don't want to do this for the reparse and
signal jobs, because they run every 15 and 5 seconds, respectively.

The info message is of the form:

    Running agent every 20 seconds with splay 5 of 10 seconds

This message is logged whenever the agent is running periodically, not for
onetime runs. Whether we're daemonized doesn't affect the behavior. This is
because we always call Puppet::Daemon#start when running periodically to
run the event loop.

lib/puppet/daemon.rb

@@ -157,7 +157,13 @@ def remove_pidfile
 
   # Loop forever running events - or, at least, until we exit.
   def run_event_loop
-    agent_run = Puppet::Scheduler.create_job(Puppet[:runinterval], Puppet[:splay], Puppet[:splaylimit]) do
+    agent_run = Puppet::Scheduler.create_job(Puppet[:runinterval], Puppet[:splay], Puppet[:splaylimit]) do |job|
+      if job.splay != 0
+        Puppet.info "Running agent every #{job.run_interval} seconds with splay #{job.splay} of #{job.splay_limit} seconds"
+      else
+        Puppet.info "Running agent every #{job.run_interval} seconds"
+      end
+
       # Splay for the daemon is handled in the scheduler
       agent.run(:splay => false)
     end

lib/puppet/scheduler/splay_job.rb

@@ -2,7 +2,7 @@
 
 module Puppet::Scheduler
   class SplayJob < Job
-    attr_reader :splay
+    attr_reader :splay, :splay_limit
 
     def initialize(run_interval, splay_limit, &block)
       @splay, @splay_limit = calculate_splay(splay_limit)

spec/unit/scheduler/splay_job_spec.rb

@@ -44,4 +44,8 @@
     job.splay_limit = splay_limit + 1
     expect(job.splay).to eq(new_splay)
   end
+
+  it "returns the splay_limit" do
+    expect(job.splay_limit).to eq(splay_limit)
+  end
 end