Introduction
Welcome to this tutorial on integrating MongoDB with Prisma using Docker. But if you've ever landed in some edgy waters, trying to synchronise all these technologies, especially in authentication, then you're not alone. Sometimes, when the container magic of Docker, the scalable database architecture of MongoDB, and the pretty nifty ORM-like Prisma layer implementation come into connection, something might go wrong, which results in auth errors that are a nightmare to resolve.
This tutorial is a way of making these hard-to-solve authentication problems easy to fix from the start. We'd run closer to the problem's inception. Let's walk out the solutions step by step and get everything up and moving. At the end of it, you'll see not only the frustration of setting everything up go down, but you'll grasp the understanding of each component and how it fits within your stack. Let's get started and turn that setup frustration into a thing of the past!
The Common Problem
Imagine that you have configured everything just perfectly—or so you believe. The application is up and running and connects to MongoDB without any errors. It feels like winning the World Cup. Reality hits when you try to interact with the database. Here is a common scenario that most of us face:
When we begin with our work, everything looks fine
Then later on, after trying to do a simple operation, such as "Creating a new user for your DB via postman," you get a huge error:
What's happening here? Although you have successfully connected at the beginning, later on, the application fails to perform operations due to a server selection timeout. This error points to DNS resolution problems, server availability problems inside the Docker network, etc. This is a very common problem that has confused many developers.
Understanding the Docker Configuration
To guarantee the smooth integration and operation of our application, we're using Docker to containerize both the application and MongoDB environments. Below is a breakdown of the key components within our Docker setup:
Application Dockerfile
This Dockerfile sets up our Node.js application:
FROM node:18-alpine3.18
WORKDIR /app
# Install Python and build tools
RUN apk add --no-cache python3 make g++
# Copy package.json and Prisma schema
COPY package*.json ./
COPY prisma/schema.prisma ./prisma/
# Install npm dependencies
RUN npm install
# Generate Prisma client
RUN npx prisma generate
# Copy the remaining application files
COPY . .
# Expose port 8000 for the application
EXPOSE 8000
# Start the application
CMD ["npm", "start"]
Key Points:
Base Image: Uses a lightweight Node.js image—
node:18-alpine3.18.Dependencies: Installs Python, make, and g++ because some npm packages require compilation.
Prisma Setup: Copies the Prisma schema and generates the Prisma client for ORM functionality.
MongoDB Dockerfile
For MongoDB, we have a custom Dockerfile within a dedicated directory named mongodb-rs in the root folder of our application.
FROM mongo:4
# Copy the custom entrypoint script
COPY mongodb-entrypoint.sh /usr/local/bin/
RUN chmod +x /usr/local/bin/mongodb-entrypoint.sh
ENTRYPOINT ["mongodb-entrypoint.sh"]
Entrypoint Script
This script automatically uses MongoDB as a replica set so that Prisma operates as expected. Prisma expects MongoDB to run as a replica set—whether a single-node replica set or a multi-node replica set—to leverage certain features.
This script should be placed inside the mongodb-rs directory to ensure that our application runs smoothly
#!/bin/sh
# Start MongoDB without authentication and with binding to all IPs
mongod --port $MONGO_REPLICA_PORT --replSet rs0 --bind_ip_all &
MONGOD_PID=$!
# Wait for MongoDB to start
while ! mongo --port $MONGO_REPLICA_PORT --eval "db.stats()"; do
sleep 1
done
# Initiate the replica set
mongo --eval "rs.initiate({_id: 'rs0', members: [{ _id: 0, host: '$MONGO_REPLICA_HOST:$MONGO_REPLICA_PORT' }]});"
# Keep the container running
echo "REPLICA SET ONLINE"
wait $MONGOD_PID
Key Points:
MongoDB Initialization: Customizes MongoDB startup to configure a replica set and bind to all IPs, ensuring it’s ready for distributed operations.
Replica Set: Essential for transactions and failover in production environments.
Docker Compose File
Here’s how both environments are orchestrated together using docker-compose.yml:
version: '3.8'
services:
db:
build: ./mongodb-rs
container_name: techdoc_db
command: ["mongod", "--bind_ip_all", "--replSet", "rs0"]
restart: always
environment:
MONGO_INITDB_ROOT_USERNAME: root
MONGO_INITDB_ROOT_PASSWORD: example
MONGO_INITDB_DATABASE: admin
MONGO_REPLICA_HOST: techdoc_db
MONGO_REPLICA_PORT: 27017
ports:
- "27017:27017"
volumes:
- mongodb_data:/data/db
app:
container_name: techdoc_app
build: ./backend
ports:
- "8000:8000"
environment:
DATABASE_URL: "mongodb://mongo-db:27017/techdb?authSource=admin&replicaSet=rs0"
depends_on:
- db
command: ["npm", "run", "start"]
volumes:
mongodb_data:
Key Points:
Service Dependencies: Ensures that the application only starts after the MongoDB service is up and running.
Environment Variables: Set up necessary credentials and connection details for MongoDB.
Container Name: You can give your container any name you choose, but I am attaching my application name to each container above.
techdoc_dbfor the database name andtechdoc_appfor the application name
This detailed setup establishes a solid groundwork for our application and highlights how Docker simplifies the management of different services in a unified environment. This configuration will be important to understanding the changes and troubleshooting steps discussed as we proceed.
Diagnosing the Issue
Solving the mystery behind those nagging connection issues between Prisma and MongoDB in Docker isn't a shot in the dark; it's a thoroughly researched inquiry. Let's unpack the mystery to find out where things are going wrong. We'll start with the most revealing clues: the logs.
MongoDB Logs:
The first check is the MongoDB logs. These log files contain valuable information. They cover anything from ordinary operations to severe warnings and alerts. Going through these logs, one could obtain details on our replica set being online, as shown below:
Prisma Back-Talk:
As we switch to Prisma, remember those early victories with the connection and readiness? They are short-lived once the errors start coming. Here's a real-life excerpt from the application logs, which discloses what might be going on in the background when you do something as innocent as checking for the presence of a user:
What do these logs tell us?
These Prisma error logs give a clear view of the problem's nature. For instance, server selection timeouts in Docker indicate DNS resolution complexity or server availability issues—a headache. Such errors often occur just after the race conditions work perfectly well, which is confusing and most often leads to lost time.
But now, with the insights from detailed MongoDB and Prisma logs, we have a more comprehensive view of the disruptions in our data flow. This dual-perspective approach gives us all the information we need to tackle the issue head-on: configurations that are not just set up but robust and reliable. Let's face these challenges head-on over the next several sections.
Fixing Authentication
Alright, let's get some of those authentication issues resolved! The gist is that our Dockerized MongoDB needs to be up and running but, importantly, configured adequately for securing with authentication. Here's how we get that in place:
Step-by-Step Process:
Get into the MongoDB CLI: To start, make sure your docker is running and open a new terminal because we need to enter the MongoDB container to configure it properly. This is the command that will bring up the MongoDB shell:
docker exec -it techdoc_db mongoCheck Current Database Users: Once inside the MongoDB shell, I want to look at what databases are around and if any users have been set up. This will help us understand what there is already in terms of the status quo:
show dbs use admin show usersYou must create an additional user when no user is appropriate or you're doing it for the first time.
Create a New User: Secure communication from Prisma to MongoDB can only work with the correct details of that user, so we have our work cut out for us.
use admin; db.createUser({ user: "root", pwd: "example", roles: [{ role: "root", db: "admin" }] });In this example, we set up a user with root privileges on the admin database, which is conveniently used for administrative purposes across all databases.
Verify That the New User Is Created: Once the user is created, it would be good to double-check and see if you did everything correctly:
show usersThis command lists all users in the current database and should let you see your newly added user.
Exit the MongoDB Shell: Once you've confirmed that your user is configured properly, you'll want to exit the MongoDB shell:
exitEnabling Authentication in MongoDB: Now that we have added the user, we must ensure that MongoDB requires authentication on all incoming connections. This is a nice feature for the security of your database.
command: ["mongod", "--auth", "--bind_ip_all"]
Add the above configuration change to your Docker Compose file or the MongoDB service definition to enforce authentication.
With these steps completed, your MongoDB is now ready and set up to both require and authenticate, properly enabling you to perform secure operations with Prisma. Ready to test out these configurations? In the next section, let's ensure everything works as it should!
Updating Prisma Configuration
Now, let's change the Prisma setup to get it in sync with our newly secured MongoDB setup.
Prisma Configuration Update
The Prisma configuration update makes the DATABASE_URL access the credentials we now have set up. Adjusting the Prisma DATABASE_URL to Work with Authenticated MongoDB Access is a significant step. You should update this DATABASE_URL on the environment variable or wherever you keep the configuration. This string should have the user and password you created for MongoDB.
DATABASE_URL="mongodb://root:example@techdoc_db:27017/techdoc?authSource=admin&replicaSet=rs0"
Be sure to replace this URL with the username, password, and database name that you set up the last section. The authSource usually is admin, where the user credentials are stored, and typically replicaSet is included since we are using a MongoDB replica set.
Here is how our newly configured docker-compose file should look
version: '3.8'
services:
db:
build: ./mongodb-rs
container_name: techdoc_db
command: ["mongod", "--auth", "--bind_ip_all", "--replSet", "rs0"]
restart: always
environment:
MONGO_INITDB_ROOT_USERNAME: root
MONGO_INITDB_ROOT_PASSWORD: example
MONGO_INITDB_DATABASE: admin
MONGO_REPLICA_HOST: techdoc_db
MONGO_REPLICA_PORT: 27017
ports:
- "27017:27017"
volumes:
- mongodb_data:/data/db
app:
container_name: techdoc_app
build: ./backend
ports:
- "8000:8000"
environment:
DATABASE_URL: "mongodb://root:example@techdoc_db:27017/techdoc?authSource=admin&replicaSet=rs0"
depends_on:
- db
command: ["npm", "run", "start"]
volumes:
mongodb_data:
Now that your MongoDB is secured and Prisma is set up to connect properly, you've just closed that gap between those two powerful tools. Next, let's continue testing your setup to ensure everything syncs perfectly!
Testing the Solution
Now that we've set the stage with our configurations, it's time to test everything. Testing not only verifies that the functionality works but also guarantees that all the pieces of the system communicate with each other in a logical, secure, and efficient manner.
Steps to Test and Confirm that the Authentication Issues Have Been Resolved:
Connection Test: Try connecting Prisma with MongoDB using the updated DATABASE_URL. A successful connection (connected and without errors) signals that the authentication settings are correct.
Data Operations: Let's perform a couple of read/write operations. You nailed it if they are successful and do not generate authentication errors! The most straightforward Prisma operation is for reading or writing data. You can do something like the following:
async function checkDatabase() { const allUsers = await prisma.user.findMany(); console.log(allUsers); } checkDatabase();Check Logs: Finally, look through the MongoDB and Prisma logs for any stray errors that appear during these tests.
Real-World Endpoint Testing
Next, let’s move beyond simple connection tests. Running an actual operation, such as fetching via an API endpoint, confirms that everything is integrated properly.
Conclusion
Phew! We have successfully navigated the maze of configuring MongoDB and Prisma in Docker, emphasising squashing those pesky authentication bugs. We have learned that creating users, enabling authentication, and fine-tuning our Prisma setup make our environment secure and robust enough to handle development and production workloads.
Remember, the heart of a healthy system always rests on testing, so never stop testing after configuration changes. This is not a set-it-and-forget-it; keep testing and making changes as necessary. Tomorrow, you will thank yourself for some easy sailing!
Thanks for sticking with me until this point in the guide! Happy coding, and may you have many victorious projects with MongoDB and Prisma in Docker!