How to use this image

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.

What's included in this Teleport image

This Docker Hardened Teleport image includes:

• teleport, the Auth Service, Proxy Service and agent binary, at /usr/local/bin/teleport
• tctl, the cluster administration tool, at /usr/local/bin/tctl
• tsh, the client, at /usr/local/bin/tsh
• tbot, the Machine & Workload Identity agent, at /usr/local/bin/tbot
• fdpass-teleport, the tsh SSH multiplexing helper, at /usr/local/bin/fdpass-teleport

Generate a configuration file

The entrypoint starts Teleport with /etc/teleport/teleport.yaml. Generate a starting configuration for a single container running the Auth Service and Proxy Service and store it on the host. The --hostname localhost flag makes localhost the node name, and therefore the cluster name, so a browser on the same machine trusts the Proxy Service's self-signed certificate:

$ mkdir -p ~/teleport/config ~/teleport/data
$ docker run --rm --hostname localhost \
  --entrypoint /usr/local/bin/teleport \
  dhi.io/teleport:<tag> configure --roles=proxy,auth > ~/teleport/config/teleport.yaml

Run the Auth Service and Proxy Service

Mount the configuration and a data directory and publish the Proxy Service web port (3080) and the Auth Service port (3025). The image runs as the nonroot user, so the mounted data directory must be writable by UID 65532:

$ chmod 0770 ~/teleport/data && sudo chown 65532:65532 ~/teleport/data
$ docker run -d --name teleport --hostname localhost \
  -v ~/teleport/config:/etc/teleport:ro \
  -v ~/teleport/data:/var/lib/teleport \
  -p 127.0.0.1:3080:3080 -p 127.0.0.1:3025:3025 \
  dhi.io/teleport:<tag>

The example binds both ports to loopback because the generated configuration uses a self-signed certificate and has no users yet. Check the Proxy Service web API:

$ curl --insecure https://localhost:3080/webapi/ping
{"auth":{"type":"local","second_factor":"otp",...},"proxy":{...},"server_version":"<version>",...}

Create the first user

Run tctl inside the running container; it talks to the Auth Service through the data directory:

$ docker exec teleport tctl users add admin --roles=editor,access --logins=root
User "admin" has been created but requires a password. Share this URL with the user to complete user setup, link is valid for 1h:
https://<proxyhost>:3080/web/invite/<token>

NOTE: Make sure <proxyhost>:3080 points at a Teleport proxy which users can access.

Open the invite link in a browser, with <proxyhost> replaced by localhost, to set the password and enrol a second factor. Set public_addr under proxy_service in teleport.yaml to have tctl print the final address.

Run a Teleport agent

Join an SSH node or other agent to an existing cluster with a join token. Generate a node configuration pointing at the Proxy Service address, create a data directory the nonroot user can write, then start the container with that configuration:

$ mkdir -p ~/teleport/node ~/teleport/node-data && chmod 0770 ~/teleport/node-data && sudo chown 65532:65532 ~/teleport/node-data
$ docker run --rm --entrypoint /usr/local/bin/teleport dhi.io/teleport:<tag> \
  node configure --proxy=teleport.example.com:443 --token=<join-token> --output=stdout > ~/teleport/node/teleport.yaml
$ docker run -d --name teleport-node \
  -v ~/teleport/node:/etc/teleport:ro \
  -v ~/teleport/node-data:/var/lib/teleport \
  dhi.io/teleport:<tag>

An SSH agent that must create host user sessions, use PAM or enhanced session recording needs root and the matching host privileges; run it with --user 0 and the capabilities your policy allows.

Run Machine & Workload Identity (tbot)

tbot is in the same image. Create a bot and a join token with tctl bots add <name> --roles=<role>, write a configuration that points at the Proxy Service and renews an identity into the data directory, then start the container with the tbot entrypoint:

$ mkdir -p ~/teleport/tbot ~/teleport/tbot-data && chmod 0770 ~/teleport/tbot-data && sudo chown 65532:65532 ~/teleport/tbot-data
$ cat > ~/teleport/tbot/tbot.yaml <<'YAML'
version: v2
proxy_server: teleport.example.com:443
onboarding:
  join_method: token
  token: <bot-join-token>
storage:
  type: directory
  path: /var/lib/teleport/bot
outputs:
  - type: identity
    destination:
      type: directory
      path: /var/lib/teleport/out
YAML
$ docker run -d --name tbot \
  --entrypoint /usr/local/bin/tbot \
  -v ~/teleport/tbot:/etc/tbot:ro \
  -v ~/teleport/tbot-data:/var/lib/teleport \
  dhi.io/teleport:<tag> start -c /etc/tbot/tbot.yaml

The renewed identity lands in ~/teleport/tbot-data/out, and tsh -i ~/teleport/tbot-data/out/identity --proxy=teleport.example.com:443 ls uses it.

Deploy with the teleport-cluster Helm chart

The upstream teleport-cluster chart accepts an image repository and a tag override. Point it at this image and pin the tag to the version you deploy:

$ helm repo add teleport https://charts.releases.teleport.dev
$ helm install teleport-cluster teleport/teleport-cluster \
  --namespace teleport-cluster --create-namespace \
  --version <version> \
  --set clusterName=teleport.example.com \
  --set image=dhi.io/teleport \
  --set teleportVersionOverride=<tag>

Non-hardened images vs. Docker Hardened Images

• The upstream teleport-distroless image runs as root. This image runs as the nonroot user (UID 65532), so mounted data directories must be writable by that UID, and SSH agents that need host privileges must be started with --user 0.
• This image declares the default Teleport ports (3023, 3024, 3025, 3026 and 3080); the upstream image declares none. Listen addresses are unchanged.
• teleport, tctl, tsh, tbot and fdpass-teleport are installed at /usr/bin and linked from /usr/local/bin, so the upstream paths keep working.
• The image does not ship the teleport-update binary, matching the upstream distroless image.
• The image is published for linux/amd64 and linux/arm64; the upstream image also publishes linux/arm/v7.
• The image sets SSL_CERT_FILE=/etc/ssl/certs/ca-certificates.crt as upstream does, pointing at the standard Docker Hardened Images CA bundle.
• FIPS variants use the Go FIPS 140-3 module for all Go cryptography. The Windows desktop access (RDP) client and the FIDO2 and PAM libraries are C and Rust components outside that module, and the Community Edition --fips flag is not available.

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 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.

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.

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.

Troubleshooting migration

The following are common issues that you may encounter during 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. To avoid issues, configure your application to listen on port 1025 or higher inside the container, even if you map it to a lower port on the host. For example, docker run -p 80:8080 my-image will work because the port inside the container is 8080, and docker run -p 80:81 my-image won't work because the port inside the container is 81.

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.