[ROMEO-1265] Exit cleanly on SIGTERM received during boot

CHANGELOG.md

@@ -5,6 +5,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 
+## [1.9.9]
+
+### Fixed
+- Exit cleanly on SIGTERM received during application boot, before the runner installs its graceful signal handling, so a shutdown mid-boot is no longer reported as a crash
+
 ## [1.9.8]
 
 - Improve performance by reusing SNS client

lib/eventboss/cli.rb

@@ -30,6 +30,8 @@ def parse(args = ARGV)
     end
 
     def run
+      setup_boot_signal_traps
+
       boot_system
 
       Eventboss.logger.info('Starting eventboss...')
@@ -39,6 +41,15 @@ def run
 
     private
 
+    # Booting the application (e.g. loading Rails) can take long enough that a
+    # termination signal arrives before Runner installs its graceful signal
+    # handling. Without a handler the process dies non-gracefully and is
+    # reported as a crash. Until Runner takes over, exit cleanly on SIGTERM so
+    # a shutdown mid-boot is not treated as a failure.
+    def setup_boot_signal_traps
+      Signal.trap('SIGTERM') { exit 0 }
+    end
+
     def boot_system
       require 'rails'
       if ::Rails::VERSION::MAJOR < 4

lib/eventboss/version.rb

@@ -1,3 +1,3 @@
 module Eventboss
-  VERSION = "1.9.8"
+  VERSION = "1.9.9"
 end

spec/eventboss/cli_spec.rb

@@ -102,5 +102,34 @@
         expect { subject.run }.to raise_error LoadError
       end
     end
+
+    describe 'when SIGTERM is received during boot' do
+      let(:default_sigterm_signal) { Signal.trap 'SIGTERM', 'SYSTEM_DEFAULT' }
+
+      after { Signal.trap 'SIGTERM', default_sigterm_signal }
+
+      it 'exits with status 0 instead of crashing' do
+        reader, writer = IO.pipe
+
+        pid = fork do
+          reader.close
+          allow(subject).to receive(:boot_system) do
+            writer.puts 'booting'
+            sleep 5
+          end
+          allow(Eventboss).to receive(:launch)
+
+          subject.run
+        end
+
+        writer.close
+        reader.gets
+
+        Process.kill 'SIGTERM', pid
+        _, status = Process.wait2(pid)
+
+        expect(status.exitstatus).to eq 0
+      end
+    end
   end
 end