Make PRESENCE_CHECK_TIMEOUT configurable via env var

app/models/shipit/task.rb

@@ -10,7 +10,6 @@ def message
       end
     end
 
-    PRESENCE_CHECK_TIMEOUT = 30
     ACTIVE_STATUSES = %w[pending running aborting].freeze
     COMPLETED_STATUSES = %w[success flapping faulty validating].freeze
     UNSUCCESSFUL_STATUSES = %w[error failed aborted flapping timedout faulty].freeze
@@ -327,15 +326,15 @@ def finished?
     end
 
     def ping
-      Shipit.redis.set(status_key, 'alive', ex: PRESENCE_CHECK_TIMEOUT)
+      Shipit.redis.set(status_key, 'alive', ex: Shipit.presence_check_timeout)
     end
 
     def alive?
       Shipit.redis.get(status_key) == 'alive'
     end
 
     def report_dead!
-      write("ERROR: Background job hasn't reported back in #{PRESENCE_CHECK_TIMEOUT} seconds.")
+      write("ERROR: Background job hasn't reported back in #{Shipit.presence_check_timeout} seconds.")
       error!
     end
 

docs/setup.md

@@ -171,6 +171,14 @@ production:
   git_progress_output: true
 ```
 
+### Environment Variables
+
+**`SHIPIT_PRESENCE_CHECK_TIMEOUT`** is the duration (in seconds) after which a deploy task is considered dead if the background job hasn't reported back. Defaults to `30`. Increase this if deploy tasks are being reaped during long-running steps like `bundle install` with native extension compilation.
+
+```bash
+export SHIPIT_PRESENCE_CHECK_TIMEOUT=120
+```
+
 ### Using Multiple Github Applications
 
 A Github application can only authenticate to the Github organization it's installed in. If you want to deploy code from multiple Github organizations the `github` section of your `config/secrets.yml` will need to be formatted differently. The top-level keys should be the name of each Github organization, and the following sub-keys are the Github app details for that particular organization.

lib/shipit.rb

@@ -92,6 +92,14 @@ def enable_samesite_middleware?
     ENV['SHIPIT_ENABLE_SAMESITE_NONE'].present?
   end
 
+  def presence_check_timeout
+    raw = ENV.fetch('SHIPIT_PRESENCE_CHECK_TIMEOUT', '30')
+    timeout = Integer(raw)
+    raise ArgumentError, "SHIPIT_PRESENCE_CHECK_TIMEOUT must be a positive integer, got #{raw.inspect}" if timeout <= 0
+
+    timeout
+  end
+
   def app_name
     @app_name ||= secrets.app_name || Rails.application.class.name.split(':').first || 'Shipit'
   end

test/unit/shipit_test.rb

@@ -30,6 +30,40 @@ class ShipitTest < ActiveSupport::TestCase
       assert_equal(['shopify/developers'], Shipit.github_teams.map(&:handle))
     end
 
+    test ".presence_check_timeout defaults to 30" do
+      assert_equal 30, Shipit.presence_check_timeout
+    end
+
+    test ".presence_check_timeout returns the configured value from ENV" do
+      ENV['SHIPIT_PRESENCE_CHECK_TIMEOUT'] = '120'
+      assert_equal 120, Shipit.presence_check_timeout
+    ensure
+      ENV.delete('SHIPIT_PRESENCE_CHECK_TIMEOUT')
+    end
+
+    test ".presence_check_timeout raises on non-numeric string" do
+      ENV['SHIPIT_PRESENCE_CHECK_TIMEOUT'] = 'abc'
+      assert_raises(ArgumentError) { Shipit.presence_check_timeout }
+    ensure
+      ENV.delete('SHIPIT_PRESENCE_CHECK_TIMEOUT')
+    end
+
+    test ".presence_check_timeout raises on zero" do
+      ENV['SHIPIT_PRESENCE_CHECK_TIMEOUT'] = '0'
+      error = assert_raises(ArgumentError) { Shipit.presence_check_timeout }
+      assert_match(/must be a positive integer/, error.message)
+    ensure
+      ENV.delete('SHIPIT_PRESENCE_CHECK_TIMEOUT')
+    end
+
+    test ".presence_check_timeout raises on negative value" do
+      ENV['SHIPIT_PRESENCE_CHECK_TIMEOUT'] = '-5'
+      error = assert_raises(ArgumentError) { Shipit.presence_check_timeout }
+      assert_match(/must be a positive integer/, error.message)
+    ensure
+      ENV.delete('SHIPIT_PRESENCE_CHECK_TIMEOUT')
+    end
+
     class RedisTest < self
       setup do
         @client = mock(:client)