What is a container registry?
A container registry is a centralized service for storing, managing, and distributing container images to ensure seamless access, whether you’re building them locally or deploying them to production. Registries can be public or private, and you can host them in the cloud or on-premises.
Docker Hub is the most widely used public registry, but alternatives like Amazon Elastic Container Registry (ECR), Azure Container Registry (ACR), and GitHub Container Registry are also popular.
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Container registries are crucial to your cloud native app’s deployment and delivery since orchestration platforms like Kubernetes pull container images from these platforms to run your workloads. But they’re more than just a storage backend—they’re also a critical link in the software supply chain. From creating and versioning app images to deploying them in production, each stage of the container lifecycle depends on this registry. That’s why teams need to choose one that aligns with their development goals and production workflows.
The container registry’s role in the software supply chain
Every step of the software supply chain relies on the container registry to ensure that workloads are consistent, secure, and traceable. The registry serves as a single source of truth as your containers move through different DevOps cycles (like dev, staging, and production). Container registries also store artifacts, including image layers, signatures, metadata, Helm charts, and OS-level packages like Debian and RPM packages.
Due to their central role, registries are a prime target for software supply chain attacks. If attackers compromise your registries, they can propagate vulnerabilities across every environment. That’s why enforcing image integrity, verifying signatures, and tracking provenance are essential for securing your software delivery chain.
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A closer look at container registry architecture
Container registries organize images into repositories and typically group them by project or service. Each repository holds tagged versions of an image, which allows teams to manage builds across environments while supporting scalable and repeatable deployments. They’re also critical for version control, image discovery, and security across environments.
To get a better idea of how modern container registries work, let’s break down their core components:
Versioning and tagging
Container registries use tags to manage image versions. When you push an image, you can assign one or more of the below tags to track app builds and updates:
Latest tag: Registries automatically use the latest tag when you don’t explicitly specify one. These tags usually point to the most recent stable version.
Custom tags: You can use custom tags based on semantic versioning or similar formats to fetch specific app builds, like
alpine:3.19.0orapp:v1.2.3.
Tagging keeps your images organized and makes it easier to pull the correct version across environments.
Cataloging
Using this feature, registries organize and surface Open Container Initiative (OCI) image data, which helps you find, manage, and retrieve the information you need quickly.
Cataloging features typically include the following:
Search and filters: Most registries allow you to search by name, tag, publisher, or attributes like “official” or “verified.”
Versioning by tag: You can pull specific versions using image tags to maintain consistent workflows across teams and environments.
Layer awareness: Registries track image layers to optimize storage and speed up image pulls with caching when possible.
This process enhances container workflows by allowing developers to get the exact container image they need.
Security
Registries also include the following built-in features to protect your images and manage access control:
Role-based access control (RBAC): Registries give developers control over who can push, pull, or manage images through RBAC roles.
Automated image scanning: Many scan for known common vulnerabilities and exposures (CVEs) and flag vulnerable images before deployment.
Signing and verification: They often support image signing tools like Docker Content Trust to sign and verify images, which prevents developers from running tampered images.
Audit logs: Registries track push, pull, and delete actions to help with forensics and compliance.
These security layers help you protect your software supply chain and maintain its integrity from build to deployment.
Container image lifecycle management tips
Frequent builds and deployments are a key aspect of modern DevOps practices, but they can quickly lead to image sprawl in your container registry. Ultimately, a lack of image lifecycle management policy results in issues like wasted storage, longer time to pull images, and registry rate limits.
Here are a few strategies you can use to keep your private registry clean and efficient:
Set retention policies: Define how long registries should retain your Docker images based on tags, usage, or age. To avoid clutter, configure your old or untagged images to automatically expire.
Automate cleanup: Use lifecycle rules, scheduled jobs, or continuous integration (CI) workflows to regularly prune unused images.
Tag images clearly: Stick to a clear tagging convention, such as semantic versions or build hashes, to signal what’s current and what’s safe to delete.
Monitor image usage: Use registry logs or analytics to identify inactive images and retire them early.
Effective image lifecycle policies keep your container registries clean. This is important because clean registries are easier to scan, safer to pull from, and faster to deploy.
Comparing 5 major container registry providers
Choosing the appropriate container registry depends on your cloud provider, security needs, CI/CD tooling, and image lifecycle strategy.
Below, we’ll compare five of the most widely used registry providers on the market:
1. Docker Hub
Docker Hub is the most well-known public container registry on the market. Nearly all OCI tooling supports it, which makes it an excellent option for sharing public images.
Key features:
Extensive ecosystem: Integrates seamlessly with all OCI-compliant tools and platforms using its extensive ecosystem
Official and verified images: Uses official and verified base images for faster, safer bootstrapping
Robust access control: Assigns granular permissions (like read, write, and admin) to teams within your Docker Hub organization using robust access control
Webhooks for automation: Triggers CI/CD pipelines automatically using webhooks whenever your team pushes a new image
Pros:
Provides a vast library of public Docker images for quick prototyping
Integrates easily with CI/CD tools and the Kubernetes ecosystem
Cons:
Includes rate limits on the free tier that can disrupt frequent builds
Lacks the enterprise-grade controls and governance features that cloud native alternatives provide
2. ACR
ACR is a managed, private container registry service that provides full support for OCI-compliant container images and artifacts.
Key features:
Geo-replication: Distributes your registry across multiple Azure regions for low-latency image pulls (along with zone redundancy on the premium plan)
Automated image operations: Allows you to build, test, and schedule container image builds via ACR Tasks when base images or source code change
Security and access control: Enforces fine-grained authentication and access control with Microsoft Entra ID (formerly Azure AD) and RBAC
Private network integration: Uses virtual networks and private endpoints (on the premium plan) to secure your private registry
Pros:
Integrates seamlessly with Azure services like AKS
Supports both Linux and Windows-based containers
Integrates with webhooks for automated CI/CD workflows
Cons:
Presents a paywall for advanced features like private network endpoints
Limits repository-level access control (scope maps) to paid plans
3. Google Artifact Registry
Google Artifact Registry is a fully managed, next-generation container registry that replaced Google Container Registry. It offers repository-level identity and access management (IAM), multi-format support, and tighter integration with Google Cloud services.
Key features:
Google Cloud Platform (GCP) integration: Integrates easily with Google Cloud IAM, Google Kubernetes Engine, and native CI/CD tools like Cloud Build and Cloud Deploy
Regional repositories: Deploys containers in specific GCP regions to reduce latency and meet regional compliance requirements
Vulnerability scanning: Allows vulnerability scanning for images using GCP’s Container Analysis API
Automatic cleanup: Automates image cleanup with lifecycle policies that remove untagged or stale images
Pros:
Simplifies cloud native development for teams that use GCP services
Hosts container and non-container artifacts in a single registry
Cons:
Limits flexibility for multi-cloud teams due to tight coupling with the Google ecosystem
Offers complicated workflows for teams with heavy open-source dependencies
4. Amazon ECR
Amazon ECR, AWS’s fully managed, OCI-compliant container registry service, focuses on reliability and security.
Key features:
AWS integration: Integrates easily with Amazon Elastic Container Service, Amazon Elastic Kubernetes Service, and Lambda to streamline AWS deployments
High availability: Ensures high availability with S3 storage, multi-AZ replication, and cross-region replication
Access control and encryption: Enforces fine-grained access control with IAM policies and encrypted images, both at rest (S3/KMS) and in transit (HTTPS)
Vulnerability scanning: Scans images automatically for known CVEs using Amazon Inspector
Pros:
Streamlines container workflows with deep integration across AWS services
Automates image scanning, replication, and encryption for secure, reliable deployments
Offers higher image download rates using ECR’s pull-through cache repositories
Cons:
Provides limited flexibility for multi-cloud or hybrid DevOps teams
Comes at a higher cost for large-scale container workloads
5. GitHub Container Registry
GitHub Container Registry is an OCI-compliant registry that integrates tightly with the GitHub ecosystem. This makes it easy to manage and publish container images as part of your existing development workflow.
Key features:
GitHub integration: Manages container images alongside your code with GitHub Actions workflows
Fine-grained access control: Allows you to set image permissions independently of repository visibility
Docker CLI support: Provides options to push and pull images using standard Docker commands with GITHUB_TOKEN or personal access tokens
Built‑in security: Automates vulnerability scanning and uses Dependabot alerts to identify image risks
Pros:
Scans container images before deploying to production
Automates container builds, publishing, and deployment via GitHub Actions
Supports repository-independent visibility settings
Cons:
Locks higher storage and data transfer quotas behind a paywall
Lacks the advanced features that cloud native registries like ACR and ECR provide
Integrating container registries into CI/CD and orchestration workflows
Your registry is the bridge between building and tagging images in CI and deploying those images into production Kubernetes clusters. Because of this, proper integration with CI/CD and orchestration tools is crucial for establishing a fast, repeatable, and secure delivery loop.
Below, we’ll explore how you can easily integrate container registries with CI/CD pipelines and orchestration platforms as part of a robust software supply chain:
Integrating with CI/CD pipelines
Whether you’re using GitHub Actions, GitLab, or Azure Pipelines, the CI/CD workflow typically follows a similar pattern: build the image, tag it, push it to your registry, and then deploy from that image.
To make this workflow more reliable, follow these steps:
Automate image builds: Configure your CI system to build and tag images on every commit or release.
Push only trusted builds: Sign container images using tools like Cosign or enable Docker Content Trust.
Integrate webhooks: Deploy new versions as soon as developers push new changes.
Organize artifacts: Group related container images in dedicated repositories and use tags to track versions and artifacts across environments.
This setup provides a clear audit trail and reduces the overhead that comes with managing the container image lifecycle.
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Integration with orchestration
Orchestration platforms use container registries as their central source for pulling container images during deployment and scaling.
Follow these tips to seamlessly integrate these platforms:
Reference exact image tags: Define image tags clearly in the deployment manifest. For example, you could use
myapp:v2.0.0instead of the latest tag.Use private registries with credentials: Set up registry authorizations to prevent unauthorized image pulls.
Enforce cluster policies: Leverage admission controllers like OPA Gatekeeper or the Wiz Admission Controller to block unsigned image pulls.
Cache frequently used images: Speed up startup times and mitigate availability risks by caching images.
Treating your container registry as a critical component of your orchestration setup ensures that your deployments consistently pull the correct image versions, scale smoothly, and remain secure throughout the container lifecycle.
Easily scan your container registries for vulnerabilities with Wiz
Container registries sit at the intersection of your software supply chain workflows. When you don’t secure them, they can become a single point of failure that spreads vulnerabilities across every stage of the pipeline.
That’s why securing containers requires looking beyond the registry. From image creation to runtime, you must monitor and harden every component in your container lifecycle.
That’s where Wiz comes in. Our platform provides end-to-end protection for your container pipelines with the following features:
Agentless scanning across registries, build systems, and runtime
Image risk correlation with real cloud exposure and identity context
Admission control enforcement to block unsigned or vulnerable images
Whether you're using Docker Hub, ACR, ECR, or self-hosted registries, Wiz integrates seamlessly to detect threats before they ship.
Ready to assess your container pipeline security? Request a demo today to take control of your container security, from registry images to runtime Docker containers.
Or, for more actionable best practices you can use to strengthen your cloud security now, download our guide to securing container registries.
