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Docker Hub MCP Server

dhi.io/hub-mcp

Docker Hub MCP Server

CIS
linux/amd64
linux/arm64

A Model Context Protocol server that integrates with Docker Hub to search, inspect, and manage images and repositories.

Prerequisites

All examples in this guide use the public image. If you’ve mirrored the repository for your own use (for example, to your Docker Hub namespace), update your commands to reference the mirrored image instead of the public one.

For example:

  • Public image: dhi.io/<repository>:<tag>
  • Mirrored image: <your-namespace>/dhi-<repository>:<tag>

For the examples, you must first use docker login dhi.io to authenticate to the registry to pull the images.

Getting Started with Docker Hub MCP Server

The Docker Hub MCP Server provides AI applications with the ability to search, inspect, and manage container images and repositories on Docker Hub through the Model Context Protocol.

Prerequisites

Before using the Docker Hub MCP Server, you'll need:

  1. Docker Hub Account: An active Docker Hub account (for private repository access)
  2. Access Token (optional): For authenticated requests and private repositories
Creating a Docker Hub Access Token

For authenticated access:

  1. Log in to Docker Hub⁠
  2. Go to Account Settings > Security > Access Tokens
  3. Click "New Access Token"
  4. Provide a description and set appropriate permissions
  5. Copy the generated token
Configuration
Claude Desktop Configuration

For public repository access:

{
  "mcpServers": {
    "docker-hub": {
      "command": "docker",
      "args": [
        "run",
        "--rm",
        "-i",
        "dhi.io/hub-mcp"
      ]
    }
  }
}

For authenticated access (private repositories):

{
  "mcpServers": {
    "docker-hub": {
      "command": "docker",
      "args": [
        "run",
        "--rm",
        "-i",
        "-e", "HUB_PAT_TOKEN=your-access-token",
        "dhi.io/hub-mcp",
        "--username",
        "<your username>"
      ]
    }
  }
}
Environment Variables

Optional environment variables for authenticated access:

  • HUB_PAT_TOKEN (optional): Your Docker Hub access token or password
Running the Server

Public access (no authentication):

docker run --rm -i \
  dhi.io/hub-mcp

Authenticated access:

docker run --rm -i \
  -e HUB_PAT_TOKEN=your-token \
  dhi.io/hub-mcp \
  --username <your username>
Available Tools

The Docker Hub MCP Server provides the following capabilities:

Image Search:

  • Search Docker Hub for public images
  • Filter by official images, automated builds
  • Search within specific namespaces

Image Inspection:

  • Get detailed image metadata
  • List available tags for an image
  • View image size, architecture, and OS
  • Check image creation and update dates

Repository Information:

  • View repository descriptions and READMEs
  • Check star counts and pull statistics
  • List repository tags
  • Access vulnerability scan results (if available)

Image Management:

  • List images in your repositories
  • View repository webhooks
  • Check repository build status
Example Use Cases

Image Discovery

Query: "Find official Python images on Docker Hub"
Server searches and returns matching official images

Tag Inspection

Query: "What tags are available for nginx?"
Server lists all tags for the nginx repository

Image Metadata

Query: "Get details about the alpine:latest image"
Server returns image size, architecture, layers, and metadata

Repository Analysis

Query: "Show me the most popular Node.js images"
Server searches and ranks images by pull count and stars

Security Checks

Query: "Does the ubuntu:22.04 image have any known vulnerabilities?"
Server retrieves vulnerability scan results if available
Security Best Practices
  1. Token Security: Store access tokens securely using environment variables or secrets management
  2. Least Privilege: Use access tokens with minimal required permissions
  3. Public vs Private: Use unauthenticated access when only public images are needed
  4. Rate Limiting: Be aware of Docker Hub API rate limits
  5. Token Rotation: Regularly rotate access tokens
Docker Hub Rate Limits

Docker Hub enforces rate limits on image pulls and API requests:

Unauthenticated requests:

  • 100 pulls per 6 hours per IP address
  • API rate limits apply

Authenticated requests:

  • Significantly higher limits based on subscription tier
  • Free accounts: 200 pulls per 6 hours
  • Pro/Team accounts: Higher limits
Performance Tips
  • Use authentication to benefit from higher rate limits
  • Cache frequently accessed image metadata
  • Use specific tags instead of latest for consistency
  • Leverage search filters to reduce API calls
Integration Examples

Check Image Updates

Query: "When was postgres:15 last updated?"
Server retrieves and returns the last update timestamp

Compare Image Sizes

Query: "What's the size difference between node:18 and node:18-alpine?"
Server compares image sizes and returns the difference

Find Official Images

Query: "List all official database images"
Server searches for official images tagged with database category

Additional Resources

Non-hardened images vs Docker Hardened Images

Key differences
FeatureNon-hardened Argo CDDocker Hardened Argo CD
SecurityStandard base with common utilitiesMinimal, hardened base with security patches
Shell accessFull shell (bash/sh) availableNo shell in runtime variants
Package managerapt/apk availableNo package manager in runtime variants
UserRuns as root by defaultRuns as nonroot user
Attack surfaceLarger due to additional utilitiesMinimal, only essential components
DebuggingTraditional shell debuggingUse Docker Debug or Image Mount for troubleshooting
Why no shell or package manager?

Docker Hardened Images prioritize security through minimalism:

  • Reduced attack surface: Fewer binaries mean fewer potential vulnerabilities
  • Immutable infrastructure: Runtime containers shouldn't be modified after deployment
  • Compliance ready: Meets strict security requirements for regulated environments

The hardened images intended for runtime don't contain a shell nor any tools for debugging. Common debugging methods for applications built with Docker Hardened Images include:

  • Docker Debug⁠ to attach to containers
  • Docker's Image Mount feature to mount debugging tools
  • Ecosystem-specific debugging approaches

Docker Debug provides a shell, common debugging tools, and lets you install other tools in an ephemeral, writable layer that only exists during the debugging session.

For example, you can use Docker Debug:

docker debug <container-name>

or mount debugging tools with the Image Mount feature:

docker run --rm -it --pid container:my-hub-mcp \
  --mount=type=image,source=dhi.io/busybox,destination=/dbg,ro \
  dhi.io/hub-mcp:<tag> /dbg/bin/sh

Image variants

Docker Hardened Images come in different variants depending on their intended use.

Runtime variants are designed to run your application in production. These images are intended to be used either directly or as the FROM image in the final stage of a multi-stage build. These images typically:

  • Run as the nonroot user
  • Do not include a shell or a package manager
  • Contain only the minimal set of libraries needed to run the app

Build-time variants typically include dev in the variant name and are intended for use in the first stage of a multi-stage Dockerfile. These images typically:

  • Run as the root user
  • Include a shell and package manager
  • Are used to build or compile applications
FIPS variants

FIPS variants include fips in the variant name and tag. They come in both runtime and build-time variants. These variants use cryptographic modules that have been validated under FIPS 140, a U.S. government standard for secure cryptographic operations.

For example, usage of MD5 fails in FIPS variants. To verify FIPS compliance, check the cryptographic module version in use by your Argo CD instance.

Migrate to a Docker Hardened Image

To migrate your application to a Docker Hardened Image, you must update your Dockerfile. At minimum, you must update the base image in your existing Dockerfile to a Docker Hardened Image. This and a few other common changes are listed in the following table of migration notes:

ItemMigration note
Base imageReplace your base images in your Dockerfile with a Docker Hardened Image.
Package managementNon-dev images, intended for runtime, don't contain package managers. Use package managers only in images with a dev tag.
Non-root userBy default, non-dev images, intended for runtime, run as the nonroot user. Ensure that necessary files and directories are accessible to the nonroot user.
Multi-stage buildUtilize images with a dev tag for build stages and non-dev images for runtime. For binary executables, use a static image for runtime.
TLS certificatesDocker Hardened Images contain standard TLS certificates by default. There is no need to install TLS certificates.
PortsNon-dev hardened images run as a nonroot user by default. As a result, applications in these images can't bind to privileged ports (below 1024) when running in Kubernetes or in Docker Engine versions older than 20.10. Argo CD default ports work without issues.
Entry pointDocker Hardened Images may have different entry points than images such as Docker Official Images. Inspect entry points for Docker Hardened Images and update your Dockerfile if necessary.
No shellBy default, non-dev images, intended for runtime, don't contain a shell. Use dev images in build stages to run shell commands and then copy artifacts to the runtime stage.

The following steps outline the general migration process.

  1. Find hardened images for your app.

    A hardened image may have several variants. Inspect the image tags and find the image variant that meets your needs.

  2. Update the base image in your Dockerfile.

    Update the base image in your application's Dockerfile to the hardened image you found in the previous step. For framework images, this is typically going to be an image tagged as dev because it has the tools needed to install packages and dependencies.

  3. For multi-stage Dockerfiles, update the runtime image in your Dockerfile.

    To ensure that your final image is as minimal as possible, you should use a multi-stage build. All stages in your Dockerfile should use a hardened image. While intermediary stages will typically use images tagged as dev, your final runtime stage should use a non-dev image variant.

  4. Install additional packages

    Docker Hardened Images contain minimal packages in order to reduce the potential attack surface. You may need to install additional packages in your Dockerfile. Inspect the image variants to identify which packages are already installed.

    Only images tagged as dev typically have package managers. You should use a multi-stage Dockerfile to install the packages. Install the packages in the build stage that uses a dev image. Then, if needed, copy any necessary artifacts to the runtime stage that uses a non-dev image.

    For Alpine-based images, you can use apk to install packages. For Debian-based images, you can use apt-get to install packages.

Troubleshoot migration

General debugging

The hardened images intended for runtime don't contain a shell nor any tools for debugging. The recommended method for debugging applications built with Docker Hardened Images is to use Docker Debug⁠ to attach to these containers. Docker Debug provides a shell, common debugging tools, and lets you install other tools in an ephemeral, writable layer that only exists during the debugging session.

Permissions

By default image variants intended for runtime, run as the nonroot user. Ensure that necessary files and directories are accessible to the nonroot user. You may need to copy files to different directories or change permissions so your application running as the nonroot user can access them.

Privileged ports

Non-dev hardened images run as a nonroot user by default. As a result, applications in these images can't bind to privileged ports (below 1024) when running in Kubernetes or in Docker Engine versions older than 20.10.

No shell

By default, image variants intended for runtime don't contain a shell. Use dev images in build stages to run shell commands and then copy any necessary artifacts into the runtime stage. In addition, use Docker Debug to debug containers with no shell.

Entry point

Docker Hardened Images may have different entry points than images such as Docker Official Images. Use docker inspect to inspect entry points for Docker Hardened Images and update your Dockerfile if necessary.