Update param docs and tests for WORKER_TTL feature

README.md

@@ -45,6 +45,22 @@ This results into the following structure, using `tree -pug`:
             └── [drwxr-x--- pulp     pulp    ]  tmp ($cache_dir)
 ```
 
+## Pulpcore settings
+
+The application will load settings from Django's defaults, Pulpcore's defaults, plus any overrides defined in the settings file at `${config_dir}/settings.py` (default: `/etc/pulp/settings.py`). The Django `diffsettings` tool is useful to check settings which are different from Django's defaults (i.e. all of the Pulpcore defaults which are not present in Django, plus any overrides defined in the settings file):
+
+```shell
+PULP_SETTINGS=/etc/pulp/settings.py pulpcore-manager diffsettings
+```
+
+For example, to check the current value of a Pulpcore setting such as `WORKER_TTL`:
+
+```shell
+PULP_SETTINGS=/etc/pulp/settings.py pulpcore-manager diffsettings | grep WORKER_TTL
+```
+
+This is useful for module parameter which configure Pulpcore settings but have an `undef` default, such as `$worker_ttl`.  When the param value is `undef`, the setting is omitted from `settings.py` and therefore Pulpcore's default is used.
+
 ## Service setup
 
 The module deploys a few systemd services:

manifests/init.pp

@@ -133,7 +133,11 @@
 #   be done incrementally with benchmarking at each step to determine an optimal value for your deployment.
 #
 # @param worker_ttl
-#   The number of seconds before a pulpcore worker should be considered lost.
+#   Configure Pulpcore's WORKER_TTL setting. This is the number of seconds before a Pulpcore worker should be considered lost.
+#   If undefined, the setting will be omitted from the configuration file and Pulpcore will use its default value.
+#   To determine the current value in Pulpcore, see instructions about the diffsettings tool in this module's README.
+#   You should not need to modify this setting unless the application reports workers timing out while they are busy completing tasks.
+#   Modification should be performed incrementally to determine the least value that prevents false positive worker timeouts.
 #
 # @param use_rq_tasking_system
 #   Use the older RQ workers tasking system instead of the newer PostgreSQL tasking system introduced in Pulpcore 3.14.

spec/acceptance/basic_spec.rb

@@ -79,11 +79,6 @@ class { 'pulpcore':
     its(:exit_status) { is_expected.to eq 0 }
   end
 
-  describe command("PULP_SETTINGS=/etc/pulp/settings.py pulpcore-manager diffsettings") do
-    its(:stdout) { is_expected.to match(/^WORKER_TTL = 30/) }
-    its(:exit_status) { is_expected.to eq 0 }
-  end
-
   describe command("DJANGO_SETTINGS_MODULE=pulpcore.app.settings PULP_SETTINGS=/etc/pulp/settings.py rq info -c pulpcore.rqconfig") do
     its(:stdout) { is_expected.to match(/^0 workers, /) }
     its(:stdout) { is_expected.not_to match(/^resource-manager /) }

spec/classes/pulpcore_spec.rb

@@ -27,6 +27,7 @@
             .with_content(%r{REDIS_URL = "redis://localhost:6379/8"})
             .with_content(%r{CACHE_ENABLED = False})
             .without_content(%r{sslmode})
+            .without_content(%r{WORKER_TTL})
           is_expected.to contain_file('/etc/pulp')
           is_expected.to contain_file('/var/lib/pulp')
           is_expected.to contain_file('/var/lib/pulp/sync_imports')
@@ -514,16 +515,14 @@
         end
       end
 
-      context 'can change the worker_ttl to 60' do
+      context 'with parameter worker_ttl = 60' do
         let :params do
-          {
-            worker_ttl: 60
-          }
+          { worker_ttl: 60 }
         end
 
-        it do
+        it 'configures pulpcore with setting WORKER_TTL = 60' do
           is_expected.to contain_concat__fragment('base')
-            .with_content(%r{\sWORKER_TTL = 60})
+            .with_content(%r{^WORKER_TTL = 60$})
         end
       end
     end

templates/settings.py.erb

@@ -22,7 +22,6 @@ DATABASES = {
 REDIS_URL = "redis://localhost:<%= scope['redis::port'] %>/<%= scope['pulpcore::redis_db'] %>"
 
 USE_NEW_WORKER_TYPE = <%= scope['pulpcore::use_rq_tasking_system'] ? "False" : "True" %>
-
 <% if scope['pulpcore::worker_ttl'] -%>
 WORKER_TTL = <%= scope['pulpcore::worker_ttl'] %>
 <% end -%>