Add conditional mapping for elasticsearch

Changelog: changed
EE: true

# Conflicts:
#	ee/lib/search/elastic/types/work_item.rb
#	ee/spec/lib/search/elastic/types/work_item_spec.rb

ee/elastic/docs/20241003142503_add_embedding_to_work_items.yml

+---
+name: AddEmbeddingToWorkItems
+version: '20241003142503'
+description: Adds the embedding field to workitems index
+group: group::global search
+milestone: '17.5'
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/163946
+skippable: true
+skip_condition: Must be on Elasticsearch 8+ or any version of OpenSearch
+obsolete: false
+marked_obsolete_by_url:
+marked_obsolete_in_milestone:

ee/elastic/migrate/20241003142503_add_embedding_to_work_items.rb

+# frozen_string_literal: true
+
+class AddEmbeddingToWorkItems < Elastic::Migration
+  include Elastic::MigrationUpdateMappingsHelper
+
+  skip_if -> { !elasticsearch_8_plus? && !opensearch? }
+
+  def index_name
+    work_item_proxy.index_name
+  end
+
+  def new_mappings
+    mappings = if elasticsearch_8_plus?
+                 work_item_proxy.elasticsearch_8_plus_mappings
+               else
+                 work_item_proxy.opensearch_mappings
+               end
+
+    mappings.merge({ routing: { type: 'text' } })
+  end
+end
+
+private
+
+def elasticsearch_8_plus?
+  helper.matching_distribution?(:elasticsearch, min_version: '8.0.0')
+end
+
+def opensearch?
+  helper.matching_distribution?(:opensearch)
+end
+
+def helper
+  @helper ||= Gitlab::Elastic::Helper.default
+end
+
+def work_item_proxy
+  Search::Elastic::Types::WorkItem
+end

ee/lib/search/elastic/types/work_item.rb

@@ -34,6 +34,38 @@ def settings
             )
           end
 
+          def elasticsearch_8_plus_mappings(mappings = {})
+            return mappings unless helper.matching_distribution?(:elasticsearch, min_version: '8.0.0')
+
+            mappings.merge({
+              embedding_0: {
+                type: 'dense_vector',
+                dims: VERTEX_TEXT_EMBEDDING_DIMENSION,
+                similarity: 'cosine',
+                index: true
+              }
+            })
+          end
+
+          def opensearch_mappings(mappings = {})
+            return mappings unless helper.matching_distribution?(:opensearch)
+
+            mappings.merge({
+              embedding_0: {
+                type: 'knn_vector',
+                dimension: VERTEX_TEXT_EMBEDDING_DIMENSION,
+                method: {
+                  name: 'hnsw',
+                  space_type: 'cosinesimil',
+                  parameters: {
+                    ef_construction: OPENSEARCH_EF_CONSTRUCTION,
+                    m: OPENSEARCH_M
+                  }
+                }
+              }
+            })
+          end
+
           private
 
           def base_mappings
@@ -68,38 +100,6 @@ def base_mappings
             }
           end
 
-          def elasticsearch_8_plus_mappings(mappings)
-            return mappings unless helper.matching_distribution?(:elasticsearch, min_version: '8.0.0')
-
-            mappings.merge({
-              embedding_0: {
-                type: 'dense_vector',
-                dims: VERTEX_TEXT_EMBEDDING_DIMENSION,
-                similarity: 'cosine',
-                index: true
-              }
-            })
-          end
-
-          def opensearch_mappings(mappings)
-            return mappings unless helper.matching_distribution?(:opensearch)
-
-            mappings.merge({
-              embedding_0: {
-                type: 'knn_vector',
-                dimension: VERTEX_TEXT_EMBEDDING_DIMENSION,
-                method: {
-                  name: 'hnsw',
-                  space_type: 'cosinesimil',
-                  parameters: {
-                    ef_construction: OPENSEARCH_EF_CONSTRUCTION,
-                    m: OPENSEARCH_M
-                  }
-                }
-              }
-            })
-          end
-
           def helper
             @helper ||= Gitlab::Elastic::Helper.default
           end

ee/spec/elastic/migrate/20241003142503_add_embedding_to_work_items_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+require File.expand_path('ee/elastic/migrate/20241003142503_add_embedding_to_work_items.rb')
+
+RSpec.describe AddEmbeddingToWorkItems, feature_category: :global_search do
+  let(:version) { 20241003142503 }
+  let(:migration) { described_class.new(version) }
+
+  describe 'migration', :elastic, :sidekiq_inline do
+    before do
+      skip 'migration is skipped' if migration.skip_migration?
+    end
+
+    include_examples 'migration adds mapping'
+  end
+
+  # rubocop:disable RSpec/AnyInstanceOf -- multiple instances of helper
+  describe '#new_mappings' do
+    context 'when using Elasticsearch 8 or higher' do
+      before do
+        allow_any_instance_of(Gitlab::Elastic::Helper).to receive(:matching_distribution?)
+          .with(:elasticsearch, min_version: '8.0.0').and_return(true)
+        allow_any_instance_of(Gitlab::Elastic::Helper).to receive(:matching_distribution?)
+          .with(:opensearch).and_return(false)
+      end
+
+      it 'returns the correct mapping for Elasticsearch' do
+        expected_mapping = {
+          routing: {
+            type: 'text'
+          },
+          embedding_0: {
+            type: 'dense_vector',
+            dims: 768,
+            similarity: 'cosine',
+            index: true
+          }
+        }
+        expect(migration.new_mappings).to eq(expected_mapping)
+      end
+    end
+
+    context 'when using OpenSearch' do
+      before do
+        allow_next_instance_of(Gitlab::Elastic::Helper) do |helper|
+          allow(helper).to receive(:matching_distribution?).with(:elasticsearch, min_version: '8.0.0').and_return(false)
+          allow(helper).to receive(:matching_distribution?).with(:opensearch).and_return(true)
+        end
+
+        allow_any_instance_of(Gitlab::Elastic::Helper).to receive(:matching_distribution?)
+          .with(:elasticsearch, min_version: '8.0.0').and_return(false)
+        allow_any_instance_of(Gitlab::Elastic::Helper).to receive(:matching_distribution?)
+          .with(:opensearch).and_return(true)
+      end
+
+      it 'returns the correct mapping for OpenSearch' do
+        expected_mapping = {
+          routing: {
+            type: 'text'
+          },
+          embedding_0: {
+            type: 'knn_vector',
+            dimension: 768,
+            method: {
+              name: 'hnsw',
+              space_type: 'cosinesimil',
+              parameters: {
+                ef_construction: 100,
+                m: 16
+              }
+            }
+          }
+        }
+        expect(migration.new_mappings).to eq(expected_mapping)
+      end
+    end
+  end
+  # rubocop:enable RSpec/AnyInstanceOf
+
+  describe 'skip_migration?' do
+    let(:helper) { Gitlab::Elastic::Helper.default }
+
+    before do
+      allow(Gitlab::Elastic::Helper).to receive(:default).and_return(helper)
+      allow(helper).to receive(:vectors_supported?).and_return(vectors_supported)
+      described_class.skip_if -> { !Gitlab::Elastic::Helper.default.vectors_supported?(:elasticsearch) }
+    end
+
+    context 'if vectors are supported' do
+      let(:vectors_supported) { true }
+
+      it 'returns false' do
+        expect(migration.skip_migration?).to be_falsey
+      end
+    end
+
+    context 'if vectors are not supported' do
+      let(:vectors_supported) { false }
+
+      it 'returns true' do
+        expect(migration.skip_migration?).to be_truthy
+      end
+    end
+  end
+end