Docker Gatsby Strapi produces ECONNREFUSED 127.0.0.1:1337 error

4 min read 06-10-2024

Docker Gatsby Strapi produces ECONNREFUSED 127.0.0.1:1337 error

Debugging ECONNREFUSED 127.0.0.1:1337: A Common Docker, Gatsby, and Strapi Headache

Have you ever encountered a frustrating "ECONNREFUSED 127.0.0.1:1337" error while developing a Gatsby website powered by a Strapi backend running in a Docker environment? This error usually signals a communication breakdown between your Gatsby frontend and your Strapi backend, preventing them from exchanging data and rendering your website.

Let's break down this common issue and explore how to troubleshoot it.

The Scenario:

Imagine this: you've set up a development environment using Docker, launched your Strapi backend on port 1337, and started your Gatsby site. However, when you try to fetch data from Strapi, you get hit with the dreaded "ECONNREFUSED 127.0.0.1:1337" error. Frustrating!

Here's a typical example of the error in your Gatsby console:

Error: Request failed with status code 500
    at createError (node_modules/@gatsbyjs/reach-router/dist/reach-router.esm.js:554:1)
    at Object.handleRequestError (node_modules/@gatsbyjs/reach-router/dist/reach-router.esm.js:759:1)
    at Object.handle (node_modules/@gatsbyjs/reach-router/dist/reach-router.esm.js:739:1)
    at invokeHook (node_modules/@gatsbyjs/reach-router/dist/reach-router.esm.js:471:1)
    at Object.handle (node_modules/@gatsbyjs/reach-router/dist/reach-router.esm.js:739:1)
    at invokeHook (node_modules/@gatsbyjs/reach-router/dist/reach-router.esm.js:471:1)
    at Object.handle (node_modules/@gatsbyjs/reach-router/dist/reach-router.esm.js:739:1)
    at invokeHook (node_modules/@gatsbyjs/reach-router/dist/reach-router.esm.js:471:1)
    at Object.handle (node_modules/@gatsbyjs/reach-router/dist/reach-router.esm.js:739:1)
    at invokeHook (node_modules/@gatsbyjs/reach-router/dist/reach-router.esm.js:471:1)
    at handle (node_modules/@gatsbyjs/reach-router/dist/reach-router.esm.js:184:1)
    at processTicksAndRejections (internal/process/task_queues.js:95:5)

  Error: Network Error
    at createError (node_modules/axios/lib/core/createError.js:16:15)
    at settle (node_modules/axios/lib/core/settle.js:17:12)
    at XMLHttpRequest.onloadend (node_modules/axios/lib/adapters/xhr.js:64:11)
  
  ECONNREFUSED 127.0.0.1:1337

Understanding the Error:

The "ECONNREFUSED" error means that your Gatsby site is trying to connect to port 1337 (where your Strapi backend is running) but the connection is being refused. This typically occurs due to one of the following reasons:

Network Misconfiguration: Your Gatsby container can't reach your Strapi container within the Docker network.
Port Conflicts: Another service might be using port 1337, blocking access for Strapi.
Firewall Issues: Your Docker host's firewall might be blocking access to the Strapi backend.
Strapi Issues: The Strapi server itself might be down or having problems starting.

Troubleshooting Steps:

Check the Network Configuration:
- Docker Networking: Ensure that both your Gatsby and Strapi containers are connected to the same Docker network. You can verify this by checking the docker network inspect <network_name> output.
- Network Access: Make sure the network configuration within your Dockerfile for your Strapi container allows access from other containers.
- Hostname Resolution: Confirm that your Gatsby container can resolve the hostname of your Strapi container. Check for mismatches between the container name and how it's being referenced within your Gatsby code.
Verify Port Availability:
- Port Conflict Check: Run docker ps -a to list all running containers and check if any other container is using port 1337.
- Change Port: If a conflict exists, change the Strapi port in your Dockerfile or Strapi configuration file to a different port, ensuring you also update the connection details in your Gatsby code.
Investigate Firewalls:
- Docker Host: Temporarily disable your Docker host's firewall (if possible) to rule out firewall blocking.
- Strapi Firewall: Check if the Strapi container has a firewall blocking inbound connections.
Verify Strapi Availability:
- Check Logs: Examine the logs of your Strapi container to see if any errors are being thrown during startup.
- Direct Access: Attempt to access your Strapi backend directly (e.g., http://localhost:1337/admin) from your Docker host to verify that the server is running properly.

Example Solution:

Let's say your Gatsby site is running in a container named "gatsby-app" and your Strapi container is named "strapi-api".

Dockerfile for Strapi:

FROM node:16-alpine
WORKDIR /app
COPY package*.json ./
RUN npm install
COPY . .
EXPOSE 1337
CMD ["npm", "run", "develop"]

Network Configuration:
- Create a Docker network called "my-app-network" to connect both containers.

Gatsby Configuration:

Update your Gatsby configuration to access Strapi using its container name:

// gatsby-config.js
module.exports = {
  siteMetadata: {
    siteUrl: "http://localhost:8000",
  },
  plugins: [
    {
      resolve: "gatsby-source-strapi",
      options: {
        apiURL: "http://strapi-api:1337", // Access Strapi via container name
        queryLimit: 1000,
        contentTypes: ["articles"],
      },
    },
    // ... other plugins
  ],
};

Docker Compose:

Define your Docker setup for both containers in a docker-compose.yml file:

version: '3.8'

services:
  strapi-api:
    build: ./strapi
    ports:
      - "1337:1337"
    networks:
      - my-app-network
  gatsby-app:
    build: ./gatsby
    ports:
      - "8000:8000"
    depends_on:
      - strapi-api
    networks:
      - my-app-network

networks:
  my-app-network:
    driver: bridge

Additional Tips:

Logs: Review the logs of both your Gatsby and Strapi containers for more specific error messages.
Clean Rebuild: Sometimes, a complete rebuild of both containers (deleting old images and restarting) can resolve issues.
Network Monitoring: Use tools like docker network inspect or docker stats to monitor the network traffic between containers.

By understanding the common causes of the "ECONNREFUSED" error and applying these troubleshooting steps, you can effectively debug and resolve connectivity problems between your Dockerized Gatsby and Strapi applications.