Add basic health check API

[LyleDavis]

This PR adds a basic health check API with a view to
a) expanding it in the future if desired
b) allowing consumers to hook in to the method to add their own processes for when to call it, for instance as part of a webserver they boot

Resolves #674

[LyleDavis]

Making @managers into a hash map would be nicer here, but I'm not sure whether it's worth it for something so small. It won't be a performance impact unless there are way more groups than I can see happening, and it's only part of the health check anyway.

[cjlarose]

Seems fine.

[cjlarose]

I think all? would be nice to use here.

diff --git a/lib/shoryuken/launcher.rb b/lib/shoryuken/launcher.rb
index e07c767..ec5a961 100644
--- a/lib/shoryuken/launcher.rb
+++ b/lib/shoryuken/launcher.rb
@@ -33,11 +33,9 @@ module Shoryuken
     end
 
     def healthy?
-      Shoryuken.groups.keys.each do |group|
-        return false unless @managers.find { |m| m.group == group }&.running?
+      Shoryuken.groups.keys.all? do |group|
+        @managers.find { |m| m.group == group }&.running?
       end
-
-      true
     end
 
     private

[LyleDavis]

I'm not sure how I can test this... The specs for this file seem a bit bare-bones so there's not much in the way of code examples 😢

[cjlarose]

Yeah, it's a little awkward. Try adding an attr_reader :launcher so we can stub the Launcher instance for a double in the spec:

diff --git a/lib/shoryuken/runner.rb b/lib/shoryuken/runner.rb
index 33459cc..a83eefa 100644
--- a/lib/shoryuken/runner.rb
+++ b/lib/shoryuken/runner.rb
@@ -15,6 +15,8 @@ module Shoryuken
     include Util
     include Singleton
 
+    attr_reader :launcher
+
     def run(options)
       self_read, self_write = IO.pipe
 
@@ -56,7 +58,7 @@ module Shoryuken
     end
 
     def healthy?
-      @launcher&.healthy? || false
+      launcher&.healthy? || false
     end
 
     private
diff --git a/spec/shoryuken/runner_spec.rb b/spec/shoryuken/runner_spec.rb
index 43f5225..1bc5228 100644
--- a/spec/shoryuken/runner_spec.rb
+++ b/spec/shoryuken/runner_spec.rb
@@ -44,6 +44,20 @@ RSpec.describe Shoryuken::Runner do
     end
   end
 
+  describe '#healthy?' do
+    let(:runner) { Shoryuken::Runner.send(:new) }
+    let(:launcher) { instance_double('Shoryuken::Launcher') }
+
+    before do
+      allow(runner).to receive(:launcher).and_return(launcher)
+    end
+
+    it 'returns true if launcher is healthy' do
+      allow(launcher).to receive(:healthy?).and_return(true)
+      expect(runner).to be_healthy
+    end
+  end
+
   describe '#daemonize' do
     it 'calls Process.daemon' do
       args = { daemon: true, logfile: '/dev/null' }

[cjlarose]

I think all? would be nice to use here.

diff --git a/lib/shoryuken/launcher.rb b/lib/shoryuken/launcher.rb
index e07c767..ec5a961 100644
--- a/lib/shoryuken/launcher.rb
+++ b/lib/shoryuken/launcher.rb
@@ -33,11 +33,9 @@ module Shoryuken
     end
 
     def healthy?
-      Shoryuken.groups.keys.each do |group|
-        return false unless @managers.find { |m| m.group == group }&.running?
+      Shoryuken.groups.keys.all? do |group|
+        @managers.find { |m| m.group == group }&.running?
       end
-
-      true
     end
 
     private

[cjlarose]

Thanks!