How to Push images to Harbor Registry Using Docker

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If you’re working with containerized applications, chances are you’ve come across Harbor—a powerful, enterprise-grade container registry. Whether you’re migrating images or integrating Harbor into your CI/CD pipeline, knowing how to push a local image tarball to Harbor is essential.

In this article, we’ll walk through how to load and push the nginx-amd64.tar image to a Harbor registry hosted at habor1.test.com.

Prerequisites

Before we begin, make sure you have:

  • Docker installed and running
  • Access to the Harbor registry (habor1.test.com)
  • A project created in Harbor (we’ll use demo in this example)
  • The image tarball: nginx-amd64.tar

Step 1: Load the Image from Tarball

Start by loading the image into your local Docker registry:

docker load -i nginx-amd64.tar

You should see output like:

Loaded image: nginx:latest

Step 1.5: Inspect the Loaded Image

To confirm the image was loaded and check its tag, run:

docker images

This will list all available images. Look for the nginx image and note its TAG and IMAGE ID. If the image shows <none> for repository or tag, use the IMAGE ID to tag it manually.

Example output:

REPOSITORY   TAG       IMAGE ID       CREATED        SIZE
<none>       <none>    abc123def456   2 hours ago    133MB

Step 1.6: Tag the Image for Harbor

Docker requires the image to be tagged with the registry address and project path. Use the IMAGE ID from the previous step:

docker tag abc123def456 habor1.test.com/demo/nginx:latest

This tells Docker:

  • abc123def456: the image ID of the loaded image
  • habor1.test.com/demo/nginx:latest: the full path to the Harbor repository, including project (demo), image name (nginx), and tag (latest)

Step 2: Log in to Harbor

Authenticate with your Harbor registry:

docker login habor1.test.com

Enter your username and password when prompted. If Harbor uses a self-signed certificate, make sure Docker trusts it by placing the CA cert in:

/etc/docker/certs.d/habor1.test.com/ca.crt

Then restart Docker:

systemctl restart docker

Step 3: Push the Image to Harbor

Now push the image to your Harbor registry:

docker push habor1.test.com/demo/nginx:latest

If everything is configured correctly, Docker will upload the image layers and register it under the demo project in Harbor.

Step 4: Verify in Harbor UI

Log into the Harbor web interface at https://habor1.test.com, navigate to the demo project, and confirm that the nginx image appears with the latest tag.