Add customizable warning not to directly edit settings.py

lib/puppet/functions/pulpcore/generate_header_content.rb

@@ -0,0 +1,20 @@
+Puppet::Functions.create_function(:'pulpcore::generate_header_content') do
+  dispatch :generate_header_content do
+    param 'Variant[String, Array[String]]', :raw_content
+    param 'Integer', :line_width
+    param 'String', :comment_glyph
+    return_type 'Array[String]'
+  end
+
+  def generate_header_content(raw_content, line_width, comment_glyph)
+    raw_content = [raw_content] unless raw_content.is_a?(Array)
+    buffer = comment_glyph * (line_width / comment_glyph.length.to_f.ceil)
+    reduced_width = line_width - (2*(1+comment_glyph.length))
+
+    raw_content.map do |text|
+      text.scan(/\S.{0,#{reduced_width}}\S(?=\s|$)|\S+/).map do |line|
+        "#{comment_glyph} " + line + (" " * (reduced_width - line.length)) + " #{comment_glyph}"
+      end.append(buffer)
+    end.flatten.prepend(buffer)
+  end
+end

manifests/config.pp

@@ -17,6 +17,8 @@
     ensure_newline => true,
   }
 
+  include pulpcore::header_strings
+
   concat::fragment { 'base':
     target  => 'pulpcore settings',
     content => template('pulpcore/settings.py.erb'),

manifests/header_strings.pp

@@ -0,0 +1,41 @@
+# @summary Re-usable, overridable strings for file headers
+#
+# @param custom_installer_name
+#   Override installer_name in headers from "Puppet" to e.g. "foreman-installer"
+#
+# @param custom_settings_explanation
+#   Custom string providing further instructions to the user in settings.py header
+class pulpcore::header_strings(
+  Optional[String] $custom_installer_name = undef,
+  Optional[String] $custom_settings_explanation = undef,
+) {
+  if $custom_installer_name {
+    $installer_name = $custom_installer_name
+  } else {
+    $installer_name = 'Puppet'
+  }
+
+  $installer_header = "File managed by ${installer_name}.\nModule: ${module_name}"
+  $warning_header   = '!!! WARNING: DO NOT EDIT THIS FILE !!!'
+
+  if $custom_settings_explanation {
+    $explanation = $custom_settings_explanation
+  } else {
+    $explanation = @("EXPLANATION"/L)
+      Not only are your edits likely to be overwritten, there is also a strong possibility \
+      of breaking your system if you change configuration here without making required \
+      changes elsewhere. Refer to the documentation you used to install Pulpcore to \
+      determine the safe and persistent way to modify the configuration.
+      | - EXPLANATION
+  }
+
+  $settings_header_content = pulpcore::generate_header_content(
+    [
+      $warning_header,
+      $installer_header,
+      $explanation,
+    ],
+    80,
+    '#',
+  )
+}

spec/classes/settings_header_spec.rb

@@ -0,0 +1,66 @@
+require 'spec_helper'
+
+describe 'pulpcore' do
+  on_supported_os.each do |os, os_facts|
+    context "on #{os}" do
+      let(:facts) { os_facts }
+
+      context 'default params' do
+        it { is_expected.to compile.with_all_deps }
+
+        it 'adds default header to settings.py' do
+          is_expected.to contain_concat__fragment('base')
+            .with_content(
+              Regexp.new(<<~HEADER.chomp),
+                ################################################################################
+                # !!! WARNING: DO NOT EDIT THIS FILE !!!                                       #
+                ################################################################################
+                # File managed by Puppet.                                                      #
+                # Module: pulpcore                                                             #
+                ################################################################################
+                # Not only are your edits likely to be overwritten, there is also a strong     #
+                # possibility of breaking your system if you change configuration here without #
+                # making required changes elsewhere. Refer to the documentation you used to    #
+                # install Pulpcore to determine the safe and persistent way to modify the      #
+                # configuration.                                                               #
+                ################################################################################
+
+                CONTENT_HOST =
+              HEADER
+            )
+        end
+      end
+
+      context 'with custom config header strings' do
+        let :pre_condition do
+          <<~PUPPET
+            class { pulpcore::header_strings:
+              custom_installer_name       => 'my_pulpcore_installer',
+              custom_settings_explanation => "Don't even think about it."
+            }
+          PUPPET
+        end
+
+        it { is_expected.to compile.with_all_deps }
+
+        it 'adds customized header to settings.py' do
+          is_expected.to contain_concat__fragment('base')
+            .with_content(
+              Regexp.new(<<~HEADER.chomp),
+                ################################################################################
+                # !!! WARNING: DO NOT EDIT THIS FILE !!!                                       #
+                ################################################################################
+                # File managed by my_pulpcore_installer.                                       #
+                # Module: pulpcore                                                             #
+                ################################################################################
+                # Don't even think about it.                                                   #
+                ################################################################################
+
+                CONTENT_HOST =
+              HEADER
+            )
+        end
+      end
+    end
+  end
+end

templates/settings.py.erb

@@ -1,3 +1,5 @@
+<%= scope['pulpcore::header_strings::settings_header_content'].join("\n") %>
+
 CONTENT_HOST = "<%= scope['pulpcore::servername'] %>"
 CONTENT_ORIGIN = "https://<%= scope['pulpcore::servername'] %>"
 SECRET_KEY = "<%= scope['pulpcore::django_secret_key'] %>"