community[patch]: Add pgvector to docker compose and update settings used in integration test (#18815)

docker/docker-compose.yml

@@ -52,6 +52,28 @@ services:
       retries: 60
     volumes:
       - postgres_data:/var/lib/postgresql/data
+  pgvector:
+    # postgres with the pgvector extension
+    image: ankane/pgvector
+    environment:
+      POSTGRES_DB: langchain
+      POSTGRES_USER: langchain
+      POSTGRES_PASSWORD: langchain
+    ports:
+      - "6024:5432"
+    command: |
+      postgres -c log_statement=all
+    healthcheck:
+      test:
+        [
+          "CMD-SHELL",
+          "psql postgresql://langchain:langchain@localhost/langchain --command 'SELECT 1;' || exit 1",
+        ]
+      interval: 5s
+      retries: 60
+    volumes:
+      - postgres_data_pgvector:/var/lib/postgresql/data
 
 volumes:
   postgres_data:
+  postgres_data_pgvector:

libs/community/tests/integration_tests/vectorstores/test_pgvector.py

@@ -9,13 +9,20 @@ from sqlalchemy.orm import Session
 from langchain_community.vectorstores.pgvector import PGVector
 from tests.integration_tests.vectorstores.fake_embeddings import FakeEmbeddings
 
+# The connection string matches the default settings in the docker-compose file
+# located in the root of the repository: [root]/docker/docker-compose.yml
+# Non-standard ports are used to avoid conflicts with other local postgres
+# instances.
+# To spin up postgres with the pgvector extension:
+# cd [root]/docker/docker-compose.yml
+# docker compose up pgvector
 CONNECTION_STRING = PGVector.connection_string_from_db_params(
     driver=os.environ.get("TEST_PGVECTOR_DRIVER", "psycopg2"),
     host=os.environ.get("TEST_PGVECTOR_HOST", "localhost"),
-    port=int(os.environ.get("TEST_PGVECTOR_PORT", "5432")),
-    database=os.environ.get("TEST_PGVECTOR_DATABASE", "postgres"),
-    user=os.environ.get("TEST_PGVECTOR_USER", "postgres"),
-    password=os.environ.get("TEST_PGVECTOR_PASSWORD", "postgres"),
+    port=int(os.environ.get("TEST_PGVECTOR_PORT", "6024")),
+    database=os.environ.get("TEST_PGVECTOR_DATABASE", "langchain"),
+    user=os.environ.get("TEST_PGVECTOR_USER", "langchain"),
+    password=os.environ.get("TEST_PGVECTOR_PASSWORD", "langchain"),
 )
 
 ADA_TOKEN_COUNT = 1536