From 6d3362f300bb1bb8a0f3b099d6b57d8552950288 Mon Sep 17 00:00:00 2001
From: Joe Rafaniello <jrafanie@redhat.com>
Date: Tue, 6 Jun 2017 15:29:31 -0400
Subject: [PATCH 1/2] Make spawn an option again instead of just fork

Use run_single_worker script for worker spawning

Embedded ansible worker overrides start_runner to implement
a thread based worker implementation.
---
 app/models/embedded_ansible_worker.rb |  1 +
 app/models/miq_worker.rb              | 21 +++++++++++++++++++++
 app/models/miq_worker/runner.rb       |  1 +
 spec/models/miq_worker_spec.rb        | 26 ++++++++++++++++++++++++++
 4 files changed, 49 insertions(+)

diff --git a/app/models/embedded_ansible_worker.rb b/app/models/embedded_ansible_worker.rb
index 2c6fa0c3517..05b49e7c924 100644
--- a/app/models/embedded_ansible_worker.rb
+++ b/app/models/embedded_ansible_worker.rb
@@ -17,6 +17,7 @@ def start_runner
         Thread.exit
       end
     end
+    nil # return no pid
   end
 
   def kill
diff --git a/app/models/miq_worker.rb b/app/models/miq_worker.rb
index 227ef77658e..00e9971c6c2 100644
--- a/app/models/miq_worker.rb
+++ b/app/models/miq_worker.rb
@@ -335,6 +335,10 @@ def self.close_pg_sockets_inherited_from_parent
   end
 
   def start_runner
+    ENV['MIQ_SPAWN_WORKERS'] ? start_runner_via_spawn : start_runner_via_fork
+  end
+
+  def start_runner_via_fork
     self.class.before_fork
     pid = fork(:cow_friendly => true) do
       self.class.after_fork
@@ -346,6 +350,23 @@ def start_runner
     pid
   end
 
+  def self.build_command_line(guid)
+    command_line = "#{Gem.ruby} #{runner_script} --heartbeat --guid=#{guid} #{name}"
+    ENV['APPLIANCE'] ? "nice #{nice_increment} #{command_line}" : command_line
+  end
+
+  def self.runner_script
+    script = ManageIQ.root.join("lib/workers/bin/run_single_worker.rb")
+    raise "script not found: #{script}" unless File.exist?(script)
+    script
+  end
+
+  def start_runner_via_spawn
+    pid = Kernel.spawn(self.class.build_command_line(guid), :out => "/dev/null", :err => [Rails.root.join("log", "evm.log"), "a"])
+    Process.detach(pid)
+    pid
+  end
+
   def start
     self.pid = start_runner
     save
diff --git a/app/models/miq_worker/runner.rb b/app/models/miq_worker/runner.rb
index 4dd26790e4d..31ca970cf71 100644
--- a/app/models/miq_worker/runner.rb
+++ b/app/models/miq_worker/runner.rb
@@ -11,6 +11,7 @@ class TemporaryFailure < RuntimeError
 
   INTERRUPT_SIGNALS = ["SIGINT", "SIGTERM"]
 
+  # DELETE ME
   OPTIONS_PARSER_SETTINGS = [
     [:guid,       'EVM Worker GUID',       String],
   ]
diff --git a/spec/models/miq_worker_spec.rb b/spec/models/miq_worker_spec.rb
index bf458efb772..704d0218cbe 100644
--- a/spec/models/miq_worker_spec.rb
+++ b/spec/models/miq_worker_spec.rb
@@ -29,6 +29,32 @@ def all_workers
     expect(result.command_line).to eq "renice -n 5 -p 123"
   end
 
+  context ".build_command_line" do
+    before do
+      allow(MiqGenericWorker).to receive(:nice_increment).and_return("+10")
+    end
+
+    it "with ENV['APPLIANCE']" do
+      begin
+        old_env = ENV.delete('DATABASE_URL')
+        ENV['APPLIANCE'] = 'true'
+        w = FactoryGirl.build(:miq_generic_worker)
+        cmd = w.class.build_command_line(123)
+        expect(cmd).to start_with("nice +10")
+        expect(cmd).to end_with("MiqGenericWorker")
+      ensure
+        # ENV['x'] = nil deletes the key because ENV accepts only string values
+        ENV['APPLIANCE'] = old_env
+      end
+    end
+
+    it "without ENV['APPLIANCE']" do
+      w = FactoryGirl.build(:miq_generic_worker)
+      cmd = w.class.build_command_line(123)
+      expect(cmd).to_not start_with("nice +10")
+    end
+  end
+
   context ".has_required_role?" do
     def check_has_required_role(worker_role_names, expected_result)
       allow(described_class).to receive(:required_roles).and_return(worker_role_names)

From 3f3a823770d4f145c97a256d62e7f679d4d76e70 Mon Sep 17 00:00:00 2001
From: Nick LaMuro <nicklamuro@gmail.com>
Date: Wed, 7 Jun 2017 16:14:46 -0500
Subject: [PATCH 2/2] Allow using existing guid for run_single_worker

When running single workers in the context of a worker monitor, the
worker records are usually already created by the monitor process by the
time the worker is forked/spawned.

Allowing the lib/worker/bin/run_single_worker.rb script to pass a guid
allows it to use those records instead of creating new ones.  If this
option isn't used, the already created ones exist along side the other
worker records, and cause evm:stop to not function properly.
---
 lib/workers/bin/run_single_worker.rb | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/lib/workers/bin/run_single_worker.rb b/lib/workers/bin/run_single_worker.rb
index 5a446dc576c..5b22aeff807 100644
--- a/lib/workers/bin/run_single_worker.rb
+++ b/lib/workers/bin/run_single_worker.rb
@@ -23,6 +23,10 @@
     options[:dry_run] = val
   end
 
+  opts.on("-g=GUID", "--guid=GUID", "Find an existing worker record instead of creating") do |val|
+    options[:guid] = val
+  end
+
   opts.on("-h", "--help", "Displays this help") do
     puts opts
     exit
@@ -52,7 +56,12 @@
 worker_class = worker_class.constantize
 worker_class.before_fork
 unless options[:dry_run]
-  worker = worker_class.create_worker_record
+  worker = if options[:guid]
+             worker_class.find_by!(:guid => options[:guid])
+           else
+             worker_class.create_worker_record
+           end
+
   begin
     worker.class::Runner.start_worker(:guid => worker.guid)
   ensure