docs: Add a more advance usecase documentation for ServerContainer (testcontainers#688)

Expanding the docs for using the ServerContainer with an example
involving FastAPI container that is using Redis container.

Author: Tranquility2

modules/generic/README.rst

@@ -18,3 +18,35 @@ FastAPI container that is using :code:`ServerContainer`
     ...         response = client.get("/")
     ...         assert response.status_code == 200
     ...         assert response.json() == {"Status": "Working"}
+
+A more advance use-case, where we are using a FastAPI container that is using Redis container:
+
+.. doctest::
+
+    >>> from testcontainers.redis import RedisContainer
+    >>> from testcontainers.generic import ServerContainer
+
+    >>> with RedisContainer() as redis:
+    ...     redis_container_port = redis.port
+    ...     redis_container_ip_address = redis.get_docker_client().bridge_ip(redis._container.id)
+
+    ...     with DockerImage(path="./modules/generic/tests/samples/advance_1", tag="advance-1:latest") as image:
+    ...         web_server = ServerContainer(port=80, image=image)
+    ...         web_server.with_env(key="REDIS_HOST", value=redis_container_ip_address)
+    ...         web_server.with_env(key="REDIS_PORT", value=redis_container_port)
+
+    ...         with web_server:
+    ...             web_server.get_api_url = lambda: web_server._create_connection_url()
+    ...             client = web_server.get_client()
+
+    ...             response = client.get("/")
+    ...             assert response.status_code == 200, "Server request failed"
+    ...             assert response.json() == {"Status": "ok"}
+
+    ...             test_data = {"key": "test_key", "value": "test_value"}
+    ...             response = client.post("/set", params=test_data)
+    ...             assert response.status_code == 200, "Failed to set data"
+
+    ...             response = client.get(f"/get/{test_data['key']}")
+    ...             assert response.status_code == 200, "Failed to get data"
+    ...             assert response.json() == {"key": test_data["key"], "value": test_data["value"]}

modules/generic/tests/samples/advance_1/Dockerfile

@@ -0,0 +1,11 @@
+FROM python:3.9
+
+WORKDIR /app
+
+RUN pip install fastapi[standard] redis
+
+COPY ./app /app
+
+EXPOSE 80
+
+CMD ["fastapi", "run", "main.py", "--port", "80"]

modules/generic/tests/samples/advance_1/app/__init__.py

@@ -0,0 +1,30 @@
+# This app will use redis to store given key-value pairs.
+
+import os
+import redis
+
+from fastapi import FastAPI
+
+
+app = FastAPI()
+
+redis_host = os.getenv("REDIS_HOST")
+redis_port = os.getenv("REDIS_PORT")
+redis_client = redis.Redis(host=redis_host, port=redis_port)
+redis_client.ping()
+
+
+@app.get("/")
+def health_check():
+    return {"status": "ok"}
+
+
+@app.get("/get/{key}")
+def read_item(key: str):
+    return {key: redis_client.get(key)}
+
+
+@app.post("/set")
+def create_item(key: str, value: str):
+    redis_client.set(key, value)
+    return {key: value}

modules/generic/tests/samples/advance_1/app/main.py

@@ -129,7 +129,7 @@ cosmosdb = ["azure-cosmos"]
 cockroachdb = []
 db2 = ["sqlalchemy", "ibm_db_sa"]
 elasticsearch = []
-generic = ["httpx"]
+generic = ["httpx", "redis"] # The advance doctests for ServerContainer require redis
 test_module_import = ["httpx"]
 google = ["google-cloud-pubsub", "google-cloud-datastore"]
 influxdb = ["influxdb", "influxdb-client"]