Container/OCI Registry

Introduction

While container registries are typically used for storing images built by the CI Pipeline, an OCI registry can store container images as well as other artifacts such as helm charts. In other words, all container registries are OCI registries, but not all OCI registries are container registries.

You can configure a container registry using any registry provider of your choice. It allows you to build, deploy, and manage your container images or charts with easy-to-use UI.

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Add Container Registry

Steps

1. From the left sidebar, go to Global Configurations → Container/OCI Registry.

   

2. Click Add Registry.

   

3. Choose a provider from the Registry provider dropdown. View the Supported Registry Providers.

4. Choose the Registry type:

   • Private Registry: Choose this if your images or artifacts are hosted or should be hosted on a private registry restricted to authenticated users of that registry. Selecting this option requires you to enter your registry credentials (username and password/token).
   • Public Registry: Unlike private registry, this doesn't require your registry credentials. Only the registry URL and repository name(s) would suffice.

5. Assuming your registry type is private, here are few of the common fields you can expect:

   Fields	Description
   Name	Provide a name to your registry, this name will appear in the Container Registry drop-down list available within the Build Configuration section of your application
   Registry URL	Provide the URL of your registry in case it doesn't come prefilled (do not include oci://, http://, or /https:// in the URL)
   Authentication Type	The credential input fields may differ depending on the registry provider, check Registry Providers
   Push container images	Tick this checkbox if you wish to use the repository to push container images. This comes selected by default and you may untick it if you don't intend to push container images after a CI build. If you wish to to use the same repository to pull container images too, read Registry Credential Access.
   Push helm packages	Tick this checkbox if you wish to push helm charts to your OCI registry
   Use as chart repository	Tick this checkbox if you want Devtron to pull helm charts from your registry and display them on chart store. Also, you will have to provide a list of repositories (present within your registry) for Devtron to successfully pull the helm charts.
   Set as default registry	Tick this checkbox to set your registry as the default registry hub for your images or artifacts

6. Click Save.

Push Helm Packages

Upon enabling this option, Devtron supports the pushing of helm charts to your OCI registry.

This is possible through isolated clusters that facilitate air-gapped deployments. In other words, it generates a helm package that you can use to deploy your application in air-gapped clusters.

If you have configured your CD pipeline to push the helm package to your OCI registry, you can view the pushed helm package in your registry as shown below:

Prerequisite

OCI registry with Use as chart repository option enabled.

Unlike Helm repos, OCI registries do not have an index file to discover all the charts. If you have helm packages pushed to your OCI registry, you can that registry as a chart repository.

Upon enabling this option, Devtron can use your OCI registry as the chart source and pull the helm charts to display them on your Chart Store for easy deployment.

Tutorial

Steps

Search your OCI registry in the list and click it.

In the List of repositories field, add your chart repo(s). You can find the username from your registry provider account.

Supported Registry Providers

ECR

Amazon ECR is an AWS-managed container image registry service. The ECR provides resource-based permissions to the private repositories using AWS Identity and Access Management (IAM). ECR allows both Key-based and Role-based authentications.

Before you begin, create an IAM user and attach the ECR policy according to the authentication type.

Provide the following additional information apart from the common fields:

Fields	Description
Registry URL	Example of URL format: xxxxxxxxxxxx.dkr.ecr.<region>.amazonaws.com where xxxxxxxxxxxx is your 12-digit AWS account ID
Authentication Type	Select one of the authentication types: EC2 IAM Role: Authenticate with workernode IAM role and attach the ECR policy (AmazonEC2ContainerRegistryFullAccess) to the cluster worker nodes IAM role of your Kubernetes cluster. User Auth: It is a key-based authentication, attach the ECR policy (AmazonEC2ContainerRegistryFullAccess) to the IAM user. Access key ID: Your AWS access key Secret access key: Your AWS secret access key ID

Docker

Provide the following additional information apart from the common fields:

Fields	Description
Username	Provide the username of the Docker Hub account you used for creating your registry.
Password/Token	Provide the password/Token corresponding to your docker hub account. It is recommended to use Token for security purpose.

Azure

For Azure, the service principal authentication method can be used to authenticate with username and password. Visit this link to get the username and password for this registry.

Provide the following additional information apart from the common fields:

Fields	Description
Registry URL/Login Server	Example of URL format: xxx.azurecr.io
Username/Registry Name	Provide the username of your Azure container registry
Password	Provide the password of your Azure container registry

Artifact Registry (GCP)

JSON key file authentication method can be used to authenticate with username and service account JSON file. Visit this link to get the username and service account JSON file for this registry.

caution

Remove all the white spaces from JSON key and wrap it in a single quote before pasting it in Service Account JSON File field

Provide the following additional information apart from the common fields:

Fields	Description
Registry URL	Example of URL format: region-docker.pkg.dev
Service Account JSON File	Paste the content of the service account JSON file

Google Container Registry (GCR)

JSON key file authentication method can be used to authenticate with username and service account JSON file. Please follow link to get the username and service account JSON file for this registry.

caution

Remove all the white spaces from JSON key and wrap it in single quote before pasting it in Service Account JSON File field

Quay

Provide the following additional information apart from the common fields:

Fields	Description
Username	Provide the username of your Quay account
Token	Provide the password of your Quay account

Other

Provide below information if you select the registry type as Other.

Fields	Description
Registry URL	Enter the URL of your private registry
Username	Provide the username of your account where you have created your registry
Password/Token	Provide the password or token corresponding to the username of your registry
Advanced Registry URL Connection Options	Allow Only Secure Connection: Tick this option for the registry to allow only secure connections Allow Secure Connection With CA Certificate: Tick this option for the registry to allow secure connection by providing a private CA certificate (ca.crt) Allow Insecure Connection: Tick this option to make an insecure communication with the registry (for e.g., when SSL certificate is expired)

info

You can use any registry which can be authenticated using docker login -u <username> -p <password> <registry-url>. However these registries might provide a more secured way for authentication, which we will support later.

Registry Credential Access

You can create a Pod that uses a Secret to pull an image from a private container registry. You can use any private container registry of your choice, for e.g., Docker Hub.

Super-admin users can decide if they want to auto-inject registry credentials or use a secret to pull an image for deployment to environments on specific clusters.

1. To manage the access of registry credentials, click Manage.

There are two options to manage the access of registry credentials:

Fields	Description
Do not inject credentials to clusters	Select the clusters for which you do not want to inject credentials
Auto-inject credentials to clusters	Select the clusters for which you want to inject credentials

2. You can choose one of the two options for defining credentials:

• Use Registry Credentials
• Specify Image Pull Secret

Use Registry Credentials

If you select Use Registry Credentials, the clusters will be auto-injected with the registry credentials of your registry type. As an example, If you select Docker as Registry Type, then the clusters will be auto-injected with the username and password/token which you use on the Docker Hub account.

Click Save.

Specify Image Pull Secret

You can create a Secret by providing credentials on the command line.

Create this Secret and name it regcred (let's say):

kubectl create -n <namespace> secret docker-registry regcred --docker-server=<your-registry-server> --docker-username=<your-name> --docker-password=<your-pword> --docker-email=<your-email>

where,

• namespace is your sub-cluster, e.g., devtron-demo
• your-registry-server is your Private Docker Registry FQDN. Use https://index.docker.io/v1/ for Docker Hub.
• your-name is your Docker username
• your-pword is your Docker password
• your-email is your Docker email

You have successfully set your Docker credentials in the cluster as a Secret called regcred.

caution

Typing secrets on the command line may store them in your shell history unprotected, and those secrets might also be visible to other users on your PC during the time when kubectl is running.

Enter the Secret name in the field and click Save.

Delete an OCI Registry

If you prefer to delete an OCI registry, follow the instructions below:

1. Navigate back to Container/OCI Registry page.

   

2. Select your preferred OCI registry.

3. Click the Delete button. The OCI registry will be deleted.

Important Note

If you used an OCI registry as a chart source, deleting the OCI registry will remove all its associated charts from the Chart Store.