Where the Request Failed
Docker timed out while waiting for the registry response, which usually points to slow network links, proxy issues, or an overloaded registry.
Docker is telling you the request failed before it got a clean response back. Treat the connection path and the failing environment as the first suspects, not the package or image name.
Restore connectivity to the registry or daemon endpoint
Retry with debug logs:docker --debug pull <image>
Validate DNS and connectivity to the registry host from the same machine.
If you use a proxy, ensure Docker is configured to use it (daemon + CLI env).
If the registry is internal, confirm health and TLS cert validity.
Manual network checks
Resolve the target host from the same machine, container, or CI runner that failed. Use nslookup <host> or dig <host> so you know DNS is pointing where you expect.
Test the target port directly with nc -vz <host> <port> or curl -Iv https://<host>/ to separate routing and proxy issues from package-manager behavior.
If the failure only happens in CI, run the same checks in that runner image or job environment instead of validating from your laptop.
Why It Happens
Usually this comes down to DNS, firewall, proxy, or VPN is blocking registry traffic, the registry is temporarily unavailable or overloaded, or corporate proxies are interfering with TLS or long-lived connections.
Prove the Failing Environment Can Reach It
Re-run the original pull/push and confirm it completes, and confirm CI runners can reach the same registry endpoint.
How Docker pulls and pushes images
Docker has to resolve the host, open a route, and complete the network connection before it can read image metadata or transfer content from the registry or daemon endpoint. That is why these failures are usually solved at the environment layer first. Until the same machine or CI runner can reach the target cleanly, changing versions or names rarely helps.
Examples
request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)Prevent Repeat Connectivity Failures
To prevent this, use a proxy/cache registry to reduce dependence on upstream availability, and keep runner network configuration consistent (DNS/proxy/firewall).