Setting up a temporary container registry

Issue

When creating a cluster, Neutree requires a container registry to distribute container images to cluster nodes. If no container registry (such as Harbor or Docker Hub) is available in the customer environment, it will not be possible to create or deploy the cluster.

Solution

Use Docker’s official registry:2 image on the control plane node to quickly set up a temporary container registry as the image distribution source for cluster deployment.

Prerequisites

Confirm that the control plane node meets the following requirements:

• Docker is installed.
• Network connectivity with cluster nodes is established.

Step 1: Start the Registry service

1. If the control plane node can pull the registry:2 image from Docker Hub, proceed to the next step to start the local Registry service. If the control plane node cannot pull the registry:2 image from Docker Hub, perform the following:

   1. Export the image in an environment with internet access:

      docker pull registry:2
      docker save registry:2 -o registry-image.tar

   2. Transfer registry-image.tar to the control plane node and load it:

      docker load -i registry-image.tar

2. Run the following command on the control plane node to start a local Registry service:

   mkdir -p /data/registry
   docker run -d \
     --name registry \
     --restart always \
     -p 5000:5000 \
     -v /data/registry:/var/lib/registry \
     registry:2

3. Verify that the Registry service is running:

   curl http://localhost:5000/v2/

   The expected response is {}, indicating that the Registry service has started successfully.

Step 2: Configure the control plane node and cluster nodes to trust the Registry

Because the temporary Registry uses HTTP (not HTTPS), refer to Using an insecure container registry to configure an insecure registry on all control plane nodes and cluster nodes.

Step 3: Upload cluster offline images

Use the Neutree CLI tool to upload the cluster offline images to the temporary Registry:

./neutree-cli-<arch> import cluster \
  --package <cluster_package> \
  --mirror-registry <control_plane_ip>:5000 \
  --registry-username test \
  --registry-password test

Parameter	Description
<arch>	CPU architecture of the server. Valid values: amd64 or aarch64.
<cluster_package>	Name of the cluster offline image.
<control_plane_ip>	IP address of the control plane node.

Step 4: Configure the container registry in Neutree

1. Log in to the Neutree management interface, click Image Registries in the left menu, and click Create.

2. Fill in the configuration:

   • URL: http://<control_plane_ip>:5000
   • For other parameters, refer to Creating a container registry.

3. Click Save.

After the configuration is complete, you can select this container registry when creating a cluster.