Installing zot with Kubernetes and Helm¶

Revised: 2022-09-12

Using Kubernetes with Helm charts for zot, you can easily deploy zot as an application in a Kubernetes cluster.

Before you begin¶

Prerequisites¶

• kubectl must be installed and a Kubernetes cluster must be ready.

• Helm must be installed.

Supported platforms¶

You can install zot on standard Linux platforms with Intel or ARM processors and with systemd installed.

Supported platforms and architectures

About binary images¶

Refer to Released Artifacts for zot for information about available zot images along with information about image variations, image locations, and image naming formats.

Installing zot¶

Step 1: Locate the Helm charts in a remote repository¶

1. Specify a remote repository that contains the Helm charts for zot. Give the repo a local name, such as project-zot, as in this example:

   $ helm repo add project-zot http://zotregistry.io/helm-charts

   "project-zot" has been added to your repositories
   

   Note:

   The Helm charts for zot are currently hosted in these publicly-accessible repositories:
   - zotregistry.io
   - artifacthub.io

2. Search the repository to see the Helm charts for zot installation. Search using the keyword 'project-zot' or 'zot', as in this example:

   $ helm search repo project-zot

   NAME             CHART VERSION  APP VERSION  DESCRIPTION
   project-zot/zot  0.1.0          v1.4.1       A Helm chart for Kubernetes
   

   Note:

   The APP VERSION is the version/tag of the zot image used for the deployment.

3. Update to the latest information of available charts from the chart repository, as shown in this example:

   $ helm repo update project-zot

   Hang tight while we grab the latest from your chart repositories...
   ...Successfully got an update from the "project-zot" chart repository
   Update Complete. ⎈Happy Helming!⎈
   

4. Display the default information of the Helm chart, as shown in this example:

$ helm show all project-zot/zot

    apiVersion: v2
    appVersion: v1.4.2-rc5
    description: A Helm chart for Kubernetes
    name: zot
    type: application
    version: 0.1.4

    # Default values for zot.
    # This is a YAML-formatted file.
    # Declare variables to be passed into your templates.
    replicaCount: 1
    image:
      repository: ghcr.io/project-zot/zot-linux-amd64
      pullPolicy: IfNotPresent
      tag: "v1.4.2-rc5"
    serviceAccount:
      create: true
      annotations: {}
      name: ""
    service:
      type: NodePort
      port: 5000

Step 2: Determine any needed changes from the Helm chart’s defaults¶

Inspect the default information of the Helm chart, as shown in the previous step. In many cases, the default chart values may be acceptable. If your installation requires any non-default settings, you may be able to specify them during the installation. Not all chart values are configurable, but you can display those that are configurable using the command in the following example:

$ helm show values project-zot/zot

  # Default values for zot.
  # This is a YAML-formatted file.
  # Declare variables to be passed into your templates.
  replicaCount: 1
  image:
    repository: ghcr.io/project-zot/zot-linux-amd64
    pullPolicy: IfNotPresent
    tag: "v1.4.2-rc5"
  serviceAccount:
    create: true
    annotations: {}
    name: ""
  service:
    type: NodePort
    port: 5000

The configurable settings in the chart are listed in the following table:

Customizing the Helm chart using 'set'¶

To override the default values in the chart, you can pass your custom values by adding the --set flag in the helm install command.

For example, if your servers use an ARM processor instead of Intel, you must change the image.repository name from zot-linux-amd64 to zot-linux-arm64:

--set image.repository=ghcr.io/project-zot/zot-linux-arm64

You can change multiple settings with one --set statement. For example, you might want your installation to have more replicas or a different port number:

--set replicaCount=2,service.port=5050

Customizing the Helm chart using a file¶

You can also create a YAML file with your overrides and then add the new file by adding the -f flag to the helm install command. For example, to override the replica count and port number, the contents of your YAML file (for example, "myfile.yaml") would be:

replicaCount: 2
service:
  port: 5050

and the following flag would be added to the helm install command:

-f myfile.yaml

Additional information¶

See the Helm documentation for further information about modifying the Helm chart.

Step 3: Install zot¶

Install zot using the helm install command. The first example shows how to perform a default installation. The additional examples show different ways to modify the helm install command to override default settings in the Helm chart:

Example 1: use default chart parameters

$ helm install zot project-zot/zot

NAME: zot
LAST DEPLOYED: Thu Aug 11 19:13:02 2022
NAMESPACE: default
STATUS: deployed
REVISION: 1
NOTES:
 Get the application URL by running these commands:
 export NODE_PORT=$(kubectl get --namespace default -o jsonpath="{.spec.ports[0].nodePort}" services zot)
 export NODE_IP=$(kubectl get nodes --namespace default -o jsonpath="{.items[0].status.addresses[0].address}")
 echo http://$NODE_IP:$NODE_PORT

Example 2: modify specific chart parameters with 'set'

$ helm install --set replicaCount=2,service.port=5050 zot project-zot/zot

Example 3: modify specific chart parameters with a file

$ helm install -f myfile.yaml zot project-zot/zot

Example 4: use a specific version of the Helm chart

$ helm install zot project-zot/zot --version 0.1.0

Example 5: link to a kubeconfig file

$ helm install zot project-zot/zot --kubeconfig $HOME/.kube/config

After the installation¶

Verify the installation¶

1. List all releases that are either deployed or failed.

   $ helm list

   NAME  NAMESPACE  REVISION  UPDATED    STATUS    CHART      APP VERSION
   zot   default    1         <datetime> deployed  zot-0.1.0  v1.4.1
   

   This response indicates that zot is deployed.

2. After making sure that your pods are up and running, execute the following commands:

   $ export NODE_PORT=$(kubectl get --namespace default -o jsonpath="{.spec.ports[0].nodePort}" services zot)
   $ export NODE_IP=$(kubectl get nodes --namespace default -o jsonpath="{.items[0].status.addresses[0].address}")
   $ echo http://$NODE_IP:$NODE_PORT
   $ curl http://$NODE_IP:$NODE_PORT/v2/_catalog
   

   The response should display the current contents of your zot repository, which should be empty immediately after installation:

   {"repositories":[]}
   

Edit the zot configuration file¶

The zot configuration file is a JSON or YAML file that contains all configuration settings for zot functions such as:

• network

• storage

• authentication

• authorization

• logging

• metrics

• synchronization with other registries

• clustering

The Helm chart installs a minimal JSON configuration file as shown below:

{
    "storage":
    {
        "rootDirectory": "/var/lib/registry"
    },
    "http":
    {
        "address": "0.0.0.0",
        "port": "5000"
    },
    "log":
    {
        "level": "debug"
    }
}

The zot configuration file is located at /etc/zot/config.json.

Refer to the Zot Administrator Guide for complete information on configuring the zot server with the zot configuration file.

Uninstalling zot¶

Should you need to uninstall zot, use the helm uninstall command, as in this example:

$ helm uninstall zot