Integration testing with Nile's Postgres platform using Docker

Nile provides a cloud offering to help build multi-tenant apps. However, it is a lot easier to build and iterate locally before using the cloud solution. Nile Docker provides all the tools required to build and test locally before moving to the cloud solution.

The image is running all the extensions and components that Nile uses as part of our cloud offering except our global control plane used to manage our customers and billing.

The Docker image includes:

• 3 Postgres instances, to emulate a distributed production-like setup
• Each Postgres instance has all the Nile extensions installed
• All functionalities documented in our docs work with the image
• At this point, the UI console is not included in the image

Join our discord to give feedback or ask questions about running and testing with Nile's Docker image.

Using Nile's docker container with TestContainers

A common way to automate integration tests is using TestContainers.

Node.js

The following example shows how to use Nile's docker container with Node.js and the TestContainers library. It exposes a Postgres port and uses waitForLog strategy to wait until the container is ready. Then it connects to the database and runs a simple query.

Make sure you install testcontainers and pg npm packages:

npm install testcontainers pg

and then you can run the following snippet:

import { GenericContainer, Wait } from "testcontainers";
import pg from "pg";

const image = "ghcr.io/niledatabase/testingcontainer:v0.0.2";
const container = await new GenericContainer(image)
  .withExposedPorts(5432)
  .withWaitStrategy(
    Wait.forLogMessage("Database has been created and is ready")
  )
  .start();

const client = new pg.Client({
  host: container.getHost(),
  port: container.getMappedPort(5432),
  user: "00000000-0000-0000-0000-000000000000",
  password: "password",
  database: "test",
});
await client.connect();
const res = await client.query("SELECT version()");
console.log(res.rows[0]);
await client.end();

Troubleshooting tip:

✏️ Note that the container uses ephemeral storage, so all the data will be lost when the container is stopped. This is intentional, as it simplifies the setup (and more importantly - the cleanup), while still allowing you to experiment and test your application.

• You can get the containter logs while tests are running by running export DEBUG=testcontainers* before running the tests.

Python

Make sure you install testcontainers and psycopg2 python packages:

pip install testcontainers psycopg2-binary

and then you can run the following snippet:

from testcontainers.postgres import PostgresContainer
from testcontainers.core.waiting_utils import wait_for_logs
import psycopg

with PostgresContainer(
    image="ghcr.io/niledatabase/testingcontainer:v0.0.2",
    port=5432,
    username="00000000-0000-0000-0000-000000000000",
    password="password",
    dbname="test",
    driver="psycopg"
) as postgres:
    delay = wait_for_logs(postgres, "Database has been created and is ready")
    connection_url = f'postgresql://00000000-0000-0000-0000-000000000000:password@localhost:{postgres.get_exposed_port(5432)}/test'
    client = psycopg.connect(connection_url)
    with client.cursor() as cursor:
        cursor.execute("SELECT version()")
        print(cursor.fetchone())

Troubleshooting tip:

✏️ Note that the container uses ephemeral storage, so all the data will be lost when the container is stopped. This is intentional, as it simplifies the setup (and more importantly - the cleanup), while still allowing you to experiment and test your application.

• On MacOS, you may need to explicitly set the DOCKER_HOST environment variable:

export DOCKER_HOST=unix:///Users/<your username>/.docker/run/docker.sock

Happy testing!