Send config events (#75)

* Send initialisation event with version and config

* Update docs for anynonimsing data and pushing tags to github

* Actioned review comments

* Action review comment: change terminlogy anonymise -> pseudonymise

* Delay sending of initialise event until after startup and until first event triggered

* Remove unecessary spec expectations when initialise event not posted

README.md

@@ -2,7 +2,7 @@
 
 **👉 Send every web request and database update to BigQuery**
 
-**✋ Skip or anonymise fields containing PII**
+**✋ Skip or pseudonymise fields containing PII**. For an explanation of pseudonymisation, see [ICO Guidance](https://ico.org.uk/media/about-the-ico/consultations/4019579/chapter-3-anonymisation-guidance.pdf)
 
 **✌️  Configure and forget**
 
@@ -250,15 +250,27 @@ If a field other than `id` is required for the user identifier, then a custom us
 DfE::Analytics.config.user_identifier = proc { |user| user&.id }
 ```
 
-#### User ID anonymisation
+#### User ID pseudonymisation
 
-The `user_id` in the web request event will not be anonymised by default. This can be changed by updating the configuration option in `config/initializers/dfe_analytics.rb`:
+The `user_id` in the web request event will not be pseudonymised by default. This can be changed by updating the configuration option in `config/initializers/dfe_analytics.rb`:
 
 ```ruby
-DfE::Analytics.config.anonymise_web_request_user_id = false
+DfE::Analytics.config.pseudonymise_web_request_user_id = false
 ```
 
-Anonymisation of `user_id` would be required if the source field in the schema is in `analytics_pii.yml` so that analysts can join the IDs together. If the `user_id` is not in `analytics_pii.yml` but is in `analytics.yml` then `user_id` anonymisation would *not* be required so that the IDs could still be joined together.
+Pseudonymisation of `user_id` would be required if the source field in the schema is in `analytics_pii.yml` so that analysts can join the IDs together. If the `user_id` is not in `analytics_pii.yml` but is in `analytics.yml` then `user_id` pseudonymisation would *not* be required so that the IDs could still be joined together.
+
+### Data Pseudonymisation Algorithm
+
+Generally all PII data should be pseudonymised, including data that directly or indirect references PII, for example database IDs.
+
+The `dfe-analytics` gem also pseudonymises such data, if it is configured to do so. If you are pseudonymising database IDs in your code (in custom events for example), then you should use the same hashing algorithm for pseudonymisation that the gem uses in order to allow joining of pseudonymised data across different database tables.
+
+The following method should be used in your code for pseudonymisation:
+
+```ruby
+DfE::Analytics.pseudonymise(value)
+```
 
 ### Adding specs
 
@@ -432,8 +444,11 @@ Please note that page caching is project specific and each project must carefull
 > 	It could be nice to have tests to prove that connectivity to GCP still works after an update, but we aren't setup for that yet.
 3. (Optional) Verify committed `CHANGELOG.md` changes and alter if necessary: `git show`
 4. Push the branch: `git push origin v${NEW_VERSION}-release`, e.g. `git push origin v1.3.0-release`
-5. Push the tags: `git push --tags`
-6. Cut a PR on GitHub with the label `version-release`, and merge once approved
+5. Cut a PR on GitHub with the label `version-release`, and wait for approval 
+6. Once the PR is approved push the tags, immediately prior to merging: `git push --tags`
+7. Merge the PR.
+
+IMPORTANT:  Pushing the tags will immediately make the release available even on a unmerged branch. Therefore, push the tags to Github only when the PR is approved and immediately prior to merging the PR.
 
 ## License
 

config/locales/en.yml

@@ -53,9 +53,9 @@ en:
             return the identifier for the user. This is useful for systems with
             users that don't use the id field.
           default: proc { |user| user&.id }
-        anonymise_web_request_user_id:
+        pseudonymise_web_request_user_id:
           description: |
-            Whether to anonymise the user_id field in the web request event.
+            Whether to pseudonymise the user_id field in the web request event.
           default: false
         rack_page_cached:
           description: |

lib/dfe/analytics.rb

@@ -12,6 +12,7 @@
 require 'dfe/analytics/load_entities'
 require 'dfe/analytics/load_entity_batch'
 require 'dfe/analytics/requests'
+require 'dfe/analytics/initialise'
 require 'dfe/analytics/version'
 require 'dfe/analytics/middleware/request_identity'
 require 'dfe/analytics/middleware/send_cached_page_request_event'
@@ -58,7 +59,7 @@ def self.config
         enable_analytics
         environment
         user_identifier
-        anonymise_web_request_user_id
+        pseudonymise_web_request_user_id
         rack_page_cached
       ]
 
@@ -68,20 +69,20 @@ def self.config
     def self.configure
       yield(config)
 
-      config.enable_analytics              ||= proc { true }
-      config.bigquery_table_name           ||= ENV['BIGQUERY_TABLE_NAME']
-      config.bigquery_project_id           ||= ENV['BIGQUERY_PROJECT_ID']
-      config.bigquery_dataset              ||= ENV['BIGQUERY_DATASET']
-      config.bigquery_api_json_key         ||= ENV['BIGQUERY_API_JSON_KEY']
-      config.bigquery_retries              ||= 3
-      config.bigquery_timeout              ||= 120
-      config.environment                   ||= ENV.fetch('RAILS_ENV', 'development')
-      config.log_only                      ||= false
-      config.async                         ||= true
-      config.queue                         ||= :default
-      config.user_identifier               ||= proc { |user| user&.id }
-      config.anonymise_web_request_user_id ||= false
-      config.rack_page_cached              ||= proc { |_rack_env| false }
+      config.enable_analytics                 ||= proc { true }
+      config.bigquery_table_name              ||= ENV['BIGQUERY_TABLE_NAME']
+      config.bigquery_project_id              ||= ENV['BIGQUERY_PROJECT_ID']
+      config.bigquery_dataset                 ||= ENV['BIGQUERY_DATASET']
+      config.bigquery_api_json_key            ||= ENV['BIGQUERY_API_JSON_KEY']
+      config.bigquery_retries                 ||= 3
+      config.bigquery_timeout                 ||= 120
+      config.environment                      ||= ENV.fetch('RAILS_ENV', 'development')
+      config.log_only                         ||= false
+      config.async                            ||= true
+      config.queue                            ||= :default
+      config.user_identifier                  ||= proc { |user| user&.id }
+      config.pseudonymise_web_request_user_id ||= false
+      config.rack_page_cached                 ||= proc { |_rack_env| false }
     end
 
     def self.initialize!
@@ -177,10 +178,15 @@ def self.extract_model_attributes(model, attributes = nil)
       allowed_attributes = attributes.slice(*exportable_attrs&.map(&:to_s))
       obfuscated_attributes = attributes.slice(*exportable_pii_attrs&.map(&:to_s))
 
-      allowed_attributes.deep_merge(obfuscated_attributes.transform_values { |value| anonymise(value) })
+      allowed_attributes.deep_merge(obfuscated_attributes.transform_values { |value| pseudonymise(value) })
     end
 
     def self.anonymise(value)
+      pseudonymise(value)
+    end
+
+    def self.pseudonymise(value)
+      # Google SQL equivalent of this is TO_HEX(SHA256(value))
       Digest::SHA2.hexdigest(value.to_s)
     end
 

lib/dfe/analytics/event.rb

@@ -5,7 +5,14 @@
 module DfE
   module Analytics
     class Event
-      EVENT_TYPES = %w[web_request create_entity update_entity delete_entity import_entity].freeze
+      EVENT_TYPES = %w[
+        web_request
+        create_entity
+        update_entity
+        delete_entity
+        import_entity
+        initialise_analytics
+      ].freeze
 
       def initialize
         time_zone = 'London'
@@ -24,9 +31,7 @@ def with_type(type)
         allowed_types = EVENT_TYPES + DfE::Analytics.custom_events
         raise 'Invalid analytics event type' unless allowed_types.include?(type.to_s)
 
-        @event_hash.merge!(
-          event_type: type
-        )
+        @event_hash.merge!(event_type: type)
 
         self
       end
@@ -119,7 +124,7 @@ def hash_to_kv_pairs(hash)
       end
 
       def anonymised_user_agent_and_ip(rack_request)
-        DfE::Analytics.anonymise(rack_request.user_agent.to_s + rack_request.remote_ip.to_s) if rack_request.remote_ip.present?
+        DfE::Analytics.pseudonymise(rack_request.user_agent.to_s + rack_request.remote_ip.to_s) if rack_request.remote_ip.present?
       end
 
       def ensure_utf8(str)
@@ -128,7 +133,7 @@ def ensure_utf8(str)
 
       def user_identifier_for(user)
         user_id = DfE::Analytics.user_identifier(user)
-        user_id = DfE::Analytics.anonymise(user_id) if user_id.present? && DfE::Analytics.config.anonymise_web_request_user_id
+        user_id = DfE::Analytics.pseudonymise(user_id) if user_id.present? && DfE::Analytics.config.pseudonymise_web_request_user_id
 
         user_id
       end

lib/dfe/analytics/initialise.rb

@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+module DfE
+  module Analytics
+    # DfE Analytics initialisation event
+    # - Event should only be sent once, but NOT on startup as this causes errors on some services
+    # - Event contains the dfe analytics version, config and other items
+    class Initialise
+      # Disable rubocop class variable warnings for class - class variable required to control sending of event
+      # rubocop:disable Style:ClassVars
+      @@initialise_event_sent = false # rubocop:disable Style:ClassVars
+
+      def self.trigger_initialise_event
+        new.send_initialise_event
+      end
+
+      def self.initialise_event_sent?
+        @@initialise_event_sent
+      end
+
+      def self.initialise_event_sent=(value)
+        @@initialise_event_sent = value # rubocop:disable Style:ClassVars
+      end
+
+      def send_initialise_event
+        return unless DfE::Analytics.enabled?
+
+        initialise_event = DfE::Analytics::Event.new
+                                                .with_type('initialise_analytics')
+                                                .with_data(initialisation_data)
+                                                .as_json
+
+        if DfE::Analytics.async?
+          DfE::Analytics::SendEvents.perform_later([initialise_event])
+        else
+          DfE::Analytics::SendEvents.perform_now([initialise_event])
+        end
+
+        @@initialise_event_sent = true # rubocop:disable Style:ClassVars
+      end
+
+      private
+
+      def initialisation_data
+        {
+          analytics_version: DfE::Analytics::VERSION,
+          config: {
+            pseudonymise_web_request_user_id: DfE::Analytics.config.pseudonymise_web_request_user_id
+          }
+        }
+      end
+      # rubocop:enable Style:ClassVars
+    end
+  end
+end

lib/dfe/analytics/send_events.rb

@@ -4,6 +4,9 @@ module DfE
   module Analytics
     class SendEvents < AnalyticsJob
       def self.do(events)
+        # The initialise event is a one-off event that must be sent to BigQuery once only
+        DfE::Analytics::Initialise.trigger_initialise_event unless DfE::Analytics::Initialise.initialise_event_sent?
+
         events = events.map { |event| event.is_a?(Event) ? event.as_json : event }
 
         if DfE::Analytics.async?

spec/dfe/analytics/entities_spec.rb

@@ -64,7 +64,7 @@
       it 'sends events that are valid according to the schema' do
         Candidate.create
 
-        expect(DfE::Analytics::SendEvents).to have_received(:perform_later) do |payload|
+        expect(DfE::Analytics::SendEvents).to have_received(:perform_later).once do |payload|
           schema = DfE::Analytics::EventSchema.new.as_json
           schema_validator = JSONSchemaValidator.new(schema, payload.first)
 

spec/dfe/analytics/event_spec.rb

@@ -125,7 +125,7 @@ def as_json
   describe 'with_user' do
     let(:regular_user_class) { Struct.new(:id) }
 
-    it 'uses user.id by default without anonymisation' do
+    it 'uses user.id by default without pseudonymisation' do
       event = described_class.new
       id = rand(1000)
       output = event.with_user(regular_user_class.new(id)).as_json
@@ -148,18 +148,18 @@ def as_json
       end
     end
 
-    context 'anonymisation of user_id' do
+    context 'pseudonymisation of user_id' do
       before do
-        allow(DfE::Analytics.config).to receive(:anonymise_web_request_user_id).and_return(true)
+        allow(DfE::Analytics.config).to receive(:pseudonymise_web_request_user_id).and_return(true)
       end
 
-      it 'anonymises the user id' do
+      it 'pseudonymises the user id' do
         event = described_class.new
         uuid = SecureRandom.uuid
-        anonymised_uuid = Digest::SHA2.hexdigest(uuid)
+        pseudonymised_uuid = Digest::SHA2.hexdigest(uuid)
         output = event.with_user(regular_user_class.new(uuid)).as_json
 
-        expect(output['user_id']).to eq anonymised_uuid
+        expect(output['user_id']).to eq pseudonymised_uuid
       end
     end
   end

spec/dfe/analytics/initialise_spec.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+RSpec.describe DfE::Analytics::Initialise do
+  before do
+    allow(DfE::Analytics::SendEvents).to receive(:perform_later)
+    allow(DfE::Analytics).to receive(:enabled?).and_return(true)
+  end
+
+  describe 'trigger_initialise_event ' do
+    it 'includes the expected attributes' do
+      described_class.trigger_initialise_event
+
+      expect(DfE::Analytics::SendEvents).to have_received(:perform_later)
+        .with([a_hash_including({
+          'event_type' => 'initialise_analytics',
+          'data' => [
+            { 'key' => 'analytics_version', 'value' => [DfE::Analytics::VERSION] },
+            { 'key' => 'config',
+              'value' => ['{"pseudonymise_web_request_user_id":false}'] }
+          ]
+        })])
+    end
+  end
+
+  describe '.initialise_event_sent=' do
+    it 'allows setting of the class variable' do
+      described_class.initialise_event_sent = true
+      expect(described_class.initialise_event_sent?).to eq(true)
+    end
+  end
+end

spec/dfe/analytics_spec.rb

@@ -5,6 +5,14 @@
     expect(DfE::Analytics::VERSION).not_to be nil
   end
 
+  it 'supports the pseudonymise method' do
+    expect(DfE::Analytics.pseudonymise('foo_bar')).to eq('4928cae8b37b3d1113f5e01e60c967df6c2b9e826dc7d91488d23a62fec715ba')
+  end
+
+  it 'supports the anonymise method for backwards compatibility' do
+    expect(DfE::Analytics.anonymise('foo_bar')).to eq('4928cae8b37b3d1113f5e01e60c967df6c2b9e826dc7d91488d23a62fec715ba')
+  end
+
   it 'has documentation entries for all the config options' do
     config_options = DfE::Analytics.config.members