Error: image ... not found

The “image not found” error means Docker could not locate the specified image locally or on any configured registry. This usually stems from a typo, a missing tag, or a network issue preventing Docker from pulling the image.

What It Means

Docker searches the local image cache first, then tries the configured registries (Docker Hub by default). If neither has the image, it returns “not found”. The error includes the full image reference you specified.

Why It Happens

• The image name or tag is misspelled (e.g., nginix instead of nginx).
• The image does not exist on the remote registry.
• The tag is missing or incorrect (e.g., node:alpine instead of node:20-alpine).
• No network connectivity to the registry.
• The image is in a private registry and you are not authenticated.

How to Fix It

1. Pull the image explicitly

docker pull <image-name>:<tag>

Example:

docker pull nginx:latest

2. List local images to check what you have

docker images

If the image is not in this list, it has not been pulled yet.

3. Verify the image name and tag on Docker Hub

Search Docker Hub for the correct name:

docker search nginx

Check available tags at hub.docker.com/r/library/<image>/tags or use a tool like skopeo:

skopeo list-tags docker://docker.io/library/nginx

4. Specify a full image reference with registry

Private registries require the full path:

docker pull myregistry.example.com/myapp:1.0

5. Authenticate to private registries

docker login myregistry.example.com

Then pull again.

6. Troubleshoot network issues

Test connectivity to Docker Hub:

ping -c 2 hub.docker.com

Check Docker’s DNS config in /etc/docker/daemon.json and restart Docker after changes.

FAQs