Fixing Axios 'ENOTFOUND' Error in Node.js Docker Container

This error typically means the DNS lookup for the external API's hostname failed within the container. Although your container can reach the internet (e.g., for pulling images), its DNS configuration might be different from your host's, causing the hostname resolution to fail.

Below are some steps you can take to troubleshoot and resolve the issue:

1. Verify the Hostname

Ensure that the hostname in your Axios request (e.g., "https://external-api.com/data") is correct. A typo or outdated domain can lead to DNS resolution failures.

2. Check DNS Resolution Inside the Container

You can get a shell inside your running container to test DNS resolution:

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docker exec -it <container_name_or_id> /bin/sh
# Inside the container, try:
nslookup external-api.com
# or
ping -c 1 external-api.com

If these commands fail to resolve the domain, it confirms a DNS issue.

3. Specify Custom DNS Servers

Sometimes Docker’s default DNS settings might not work well with certain external domains. You can force your container to use a public DNS server (e.g., Google's 8.8.8.8) by adding the --dns flag when running your container:

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docker run --dns=8.8.8.8 -d <your_image>

Alternatively, you can adjust Docker's daemon settings by editing or creating the /etc/docker/daemon.json file on your host:

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{
  "dns": ["8.8.8.8", "8.8.4.4"]
}

After making the change, restart the Docker daemon.

4. Verify Network Mode and Environment Variables

While you've already tried --network host, double-check that no other network configurations (such as proxy settings or custom network configurations) in your container or host environment are interfering with DNS resolution.

5. Test with a Minimal Example

To isolate the issue, create a minimal Node.js script with Axios in the container that only performs the DNS lookup. For example:

JAVASCRIPTCopied
const axios = require('axios');

const fetchData = async () => {
    try {
        const response = await axios.get('https://external-api.com/data');
        console.log(response.data);
    } catch (error) {
        console.error('Error: ', error.message);
    }
};

fetchData();

Run this script after applying the above DNS changes. If it works, the issue is likely limited to DNS resolution in your Docker configuration rather than the code itself.

By following these steps, you should be able to pinpoint and resolve the DNS resolution issue that's causing the ENOTFOUND error within your Docker container.