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/renovate:44-debian13 or dhi.io/renovate:44-alpine3.24
• Mirrored image: <your-namespace>/dhi-renovate:44-debian13 or <your-namespace>/dhi-renovate:44-alpine3.24

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

Debian publishes the unqualified tag 44 and the line tag 44-debian13. Alpine publishes the line tags 44-alpine and 44-alpine3.24. The commands below use the line tag for each distribution.

Renovate is a command-line tool. A run scans a project directory and exits. It does not listen on a port. Project documentation is at https://github.com/renovatebot/renovate⁠ and https://docs.renovatebot.com/⁠.

What's included in this Renovate image

This Docker Hardened Renovate image includes:

• renovate — Scans a repository and looks up newer versions of pinned dependencies.
• renovate-config-validator — Checks a Renovate config file and exits non-zero on an unknown option.

The entrypoint is /usr/local/sbin/renovate-entrypoint.sh. When the first argument starts with -, or is not an executable on PATH, the entrypoint runs renovate with those arguments. Both binaries above are on PATH.

Start a Renovate image

Check the version

This example uses the Debian image:

$ docker run --rm dhi.io/renovate:44-debian13 --version

The command prints the image's Renovate version.

Scan a local project

The local platform⁠ scans the working directory inside the container, /usr/src/app, and does not open a pull request. Mount the project on that path. The directory and its files must be readable by uid 65532.

Create package.json:

{
  "name": "demo",
  "dependencies": {
    "lodash": "4.17.20"
  }
}

Create renovate.json:

{
  "extends": []
}

From the directory that contains those files, run the Debian image. --platform=local selects the local platform. --onboarding=false skips the onboarding branch because renovate.json is already present. --dry-run=extract stops after reading dependency files.

$ docker run --rm -v "$PWD:/usr/src/app" dhi.io/renovate:44-debian13 --platform=local --onboarding=false --dry-run=extract

Renovate reports the pinned lodash dependency from package.json and exits 0. The local platform's default is a lookup dry run, which queries package registries over the network. The command above passes --dry-run=extract so it stops before that lookup. See the local platform documentation for lookup mode.

Common Renovate use cases

Validate a configuration file

renovate-config-validator checks a config file. This example uses the Alpine image. Save the following as config.js. The file must be readable by uid 65532.

module.exports = {
  platform: 'local',
};

$ docker run --rm -v "$PWD/config.js:/usr/src/app/config.js:ro" dhi.io/renovate:44-alpine3.24 renovate-config-validator /usr/src/app/config.js

The validator prints Config validated successfully.

Non-hardened images vs. Docker Hardened Images

This image replaces docker.io/renovate/renovate for the Renovate CLI. The entrypoint remains /usr/local/sbin/renovate-entrypoint.sh, the default command remains renovate, and the working directory remains /usr/src/app. The differences below change a migrated run.

User id. Upstream runs as uid 12021. This runtime image runs as uid 65532, group 65532. A volume created for uid 12021 is not writable by uid 65532. Grant uid 65532 read access to every mounted path, and write access where Renovate must update files. Dev images (44-debian13-dev and 44-alpine3.24-dev) and the fips-dev variants run as root.

Binary source. This image sets RENOVATE_BINARY_SOURCE=global. Upstream leaves that variable unset, which selects binarySource=install: containerbase downloads package managers during the run. This image does not download package managers at runtime. git, bash, and node are already on PATH. Bash is present because the entrypoint is a bash script. The image does not include containerbase, OpenSSH, curl, or GnuPG, and it is not the upstream -full image.

Directories. These paths exist with mode 0770 and owner 65532:65532:

• /tmp/renovate
• /runner/cache/renovate/repository
• /usr/src/app
• /home/nonroot

Upstream creates the cache paths with mode 0777. A mount that replaces one of these directories must be writable by uid 65532.

Shell environment. This image sets LANG=C.UTF-8 and LC_ALL=C.UTF-8. Upstream sets BASH_ENV and ENV to /usr/local/etc/env. This image does not set BASH_ENV or ENV, so a shell does not source /usr/local/etc/env.

Init. PID 1 is tini at /usr/local/sbin/tini. Upstream uses dumb-init.

Image variants

Docker Hardened Images come in different variants depending on their intended use. Image variants are identified by their tag.

• 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 a 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 tag 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.

To view the image variants and get more information about them, select the Tags tab for this repository, and then select a tag.

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.