Docker Pull - connection reset by peer

3 min read 05-10-2024

Docker Pull - Connection Reset By Peer: Troubleshooting and Solutions

Pulling images from Docker Hub or other registries is a fundamental task in any Docker workflow. However, you might encounter the error "connection reset by peer" during this process. This error can be frustrating and often leaves developers scratching their heads. This article will guide you through the common causes of this error and provide practical solutions to get your Docker pulls working again.

Understanding the Problem

"Connection reset by peer" is a network error that signals an abrupt termination of a connection. In the context of Docker pulls, this typically means that the Docker client has lost connection with the registry server before completing the image download. This can happen due to a variety of reasons, ranging from transient network glitches to more complex configuration issues.

Scenario and Original Code

Here's a typical scenario where this error might occur:

docker pull ubuntu:latest

You might see an output like:

Using default tag: latest
Error response from daemon: Get https://registry-1.docker.io/v2/library/ubuntu/manifests/latest: unexpected EOF

Followed by the dreaded "connection reset by peer" error message.

Analyzing the Issue

Here are the most common causes of the "connection reset by peer" error during Docker pulls:

1. Network Connectivity Issues:

Transient Network Problems: Your internet connection might be experiencing temporary disruptions or latency.
Firewall Blocking: Your firewall might be blocking outbound connections to the registry server.
Proxy Configuration: If you're behind a proxy, the Docker client might not be properly configured to use it.
DNS Resolution Errors: Your system might be unable to resolve the hostname of the registry server.

2. Registry Issues:

Server Overload: The registry server you're trying to pull from might be under heavy load.
Registry Downtime: The registry server could be experiencing temporary downtime.
Rate Limiting: You might be exceeding the rate limit for pulling images from the registry.

3. Docker Daemon Configuration:

Insufficient Resources: The Docker daemon might be running on a system with insufficient memory or CPU resources.
Docker Daemon Crashes: The Docker daemon itself might be crashing or encountering errors.

Solutions and Troubleshooting Steps

1. Verify Network Connectivity:

Ping the Registry Server: Ping the hostname of the registry server to confirm network connectivity. For example: ping registry-1.docker.io
Check Network Status: Use tools like ping, traceroute, or nslookup to diagnose network issues.
Restart Network Devices: Reboot your router, modem, or network interface card (NIC) to refresh the network connection.

2. Configure Proxy Settings:

Docker Configuration: Set the http_proxy and https_proxy environment variables in your Docker daemon configuration file.
System-wide Proxy: Configure your system-wide proxy settings in your operating system.

3. Disable Firewall Restrictions:

Temporary Firewall Disabling: Temporarily disable your firewall to rule out network restrictions.
Firewall Rules: Add specific rules to allow outbound connections to the registry server.

4. Check Registry Status:

Check Docker Hub Status: For Docker Hub, check the status page for any known outages or maintenance schedules.
Contact Registry Admin: If you're using a private registry, contact the registry administrator for assistance.

5. Increase Docker Daemon Resources:

Increase Memory and CPU: Allocate more memory and CPU resources to your Docker daemon by editing the Docker daemon configuration file.
Restart Docker Daemon: After making configuration changes, restart the Docker daemon.

6. Restart Docker Daemon:

Restart Command: Use the docker restart docker command to restart the Docker daemon.

7. Clean Up Docker Cache:

Remove Unused Images: Use docker rmi <image_id> to remove any unused or corrupt images.
Clear Docker Cache: Use docker system prune to remove dangling images, networks, and volumes.

8. Retry Pull Operation:

Wait and Retry: Wait for a few minutes and retry the docker pull command.
Use Different Registry: Try pulling the image from a different registry mirror, if available.

Additional Tips:

Use VPN: Consider using a VPN to bypass any network restrictions or firewalls.
Use Docker Desktop: Docker Desktop for Windows and macOS provides a user-friendly interface and handles most network configurations automatically.

Conclusion

Encountering the "connection reset by peer" error during Docker pulls can be frustrating. However, by understanding the common causes and following the troubleshooting steps outlined above, you can usually resolve the issue quickly and efficiently. Remember to check your network connectivity, proxy settings, registry status, and Docker daemon configuration. By using the right combination of troubleshooting techniques, you'll be back on track to building and deploying your Docker applications in no time.

Docker Pull - connection reset by peer