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Docker

Renovate supports upgrading dependencies in various types of Docker definition files:

  • Docker's Dockerfile files
  • Docker Compose docker-compose.yml, compose.yml files
  • CircleCI config files
  • Kubernetes manifest files
  • Ansible configuration files

How It Works

  1. Renovate searches in each repository for any files matching each manager's configured fileMatch pattern(s)
  2. Matching files are parsed, Renovate checks if the file(s) has any Docker image references (e.g. FROM lines in a Dockerfile)
  3. If the image tag in use "looks" like a version (e.g. myimage:1, myimage:1.1, myimage:1.1.0, myimage:1-onbuild) then Renovate checks the Docker registry for upgrades (e.g. from myimage:1.1.0 to myimage:1.2.0)

Preservation of Version Precision

By default, Renovate preserves the precision level specified in the Docker images. For example, if the existing image is pinned at myimage:1.1 then Renovate only proposes upgrades to myimage:1.2 or myimage:1.3. This means that you will not get upgrades to a more specific versions like myimage:1.2.0 or myimage:1.3.0. Renovate does not yet support "pinning" an imprecise version to a precise version, e.g. from myimage:1.2 to myimage:1.2.0, but it's a feature we'd like to work on one day.

Version compatibility

Although suffixes in SemVer indicate pre-releases (e.g. v1.2.0-alpha.2), in Docker they typically indicate compatibility, e.g. 1.2.0-alpine. By default Renovate assumes suffixes indicate compatibility, for this reason Renovate will not change any suffixes. Renovate will update 1.2.0-alpine to 1.2.1-alpine but never updates to 1.2.1 or 1.2.1-stretch as that would change the suffix.

If this behavior does not suit a particular package you have, Renovate allows you to customize the versioning scheme it uses. For example, you have a Docker image foo/bar that sticks to SemVer versioning. This means that you need to tell Renovate that suffixes indicate pre-release versions, and not compatibility.

You could then use this packageRules array, to tell Renovate to use semver versioning for the foo/bar package:

{
  "packageRules": [
    {
      "matchDatasources": ["docker"],
      "matchPackageNames": ["foo/bar"],
      "versioning": "semver"
    }
  ]
}

Another example is the official python image, which follows pep440 versioning. You can tell Renovate to use the pep440 versioning scheme with this set of packageRules:

{
  "packageRules": [
    {
      "matchDatasources": ["docker"],
      "matchPackageNames": ["python"],
      "versioning": "pep440"
    }
  ]
}

If traditional versioning doesn't work, try Renovate's built-in loose versioning. Renovate will perform a best-effort sort of the versions, regardless of whether they have letters or digits.

If both the traditional versioning, and the loose versioning do not give the results you want, try the regex versioning. This approach uses regex capture group syntax to specify which part of the version string is major, minor, patch, pre-release, or compatibility. See the docs for versioning for documentation and examples of regex versioning in action.

Digest Pinning

We recommend that you pin your Docker images to an exact digest. By pinning to a digest you make your Docker builds immutable, every time you do a pull you get the same content.

If you work with dependencies in the JavaScript/npm ecosystem, you may be used to exact versions being immutable. For example, if you set a version like 2.0.1, you and your colleagues always get the exact same "code".

Docker's tags are not immutable versions, even if tags look like a version. You probably expect myimage:1 and myimage:1.2 to change over time, but you might incorrectly assume that myimage:1.2.0 never changes. Although it probably shouldn't, the reality is that any Docker image tag can change content, and potentially break.

By replacing Docker tags with Docker digests as the image's primary identifier you'll get immutable builds. It's hard to work with strings like FROM node@sha256:d938c1761e3afbae9242848ffbb95b9cc1cb0a24d889f8bd955204d347a7266e. Luckily Renovate can update the digests for you, so you don't have to.

To keep things simple, Renovate keeps the Docker tag in the FROM line, like this: FROM node:14.15.1@sha256:d938c1761e3afbae9242848ffbb95b9cc1cb0a24d889f8bd955204d347a7266e.

Digest Updating

If you follow our advice to replace a simple tag like node:14 with a pinned digest node:14@sha256:d938c1761e3afbae9242848ffbb95b9cc1cb0a24d889f8bd955204d347a7266e, you will get Renovate PRs whenever the node:14 image is updated on Docker Hub.

Previously this update would have been "invisible" to you - one day you pull code that represents node:14.15.0 and the next day you pull code that represents node:14.15.1. But you can never be sure, especially as Docker caches. Maybe some of your colleagues, or worse still your build machine, are stuck on an older version with a security vulnerability.

By pinning to a digest instead, you will get these updates via Pull Requests, or even committed directly to your repository if you enable branch automerge for convenience. This makes sure everyone on your team uses the latest versions.

Version Upgrading

Renovate also supports upgrading versions in Docker tags, e.g. from myimage:1.2.0 to myimage:1.2.1 or myimage:1.2 to myimage:1.3. If a tag looks like a version, Renovate will upgrade it like a version.

We recommend you use the major.minor.patch tagging scheme, e.g. change from myimage:1 to myimage:1.1.1. This way it's easy to see what the Renovate PR is going to change. You can see the difference between a PR that upgrades myimage from 1.1.1 to 1.1.2 and a PR that changes the contents of the version you already use (1.1.1).

By default, Renovate will upgrade minor/patch versions (like from 1.2.0 to 1.2.1), but not upgrade major versions. If you wish to enable major versions then add the preset docker:enableMajor to your extends array in your renovate.json.

Renovate has some Docker-specific intelligence when it comes to versions. For example:

Ubuntu codenames

Renovate understands Ubuntu release code names and will offer upgrades to the latest LTS release (e.g. from ubuntu:xenial to ubuntu:focal).

For this to work you must follow this naming scheme:

  • The first term of the full codename is used (e.g. bionic for Bionic Beaver release)
  • The codename is in lowercase

For example, Renovate will offer to upgrade the following Dockerfile layer:

FROM ubuntu:yakkety

To:

FROM ubuntu:focal

Debian codenames

Renovate understands Debian release code names and rolling updates schedule and will offer upgrades to the latest stable release (e.g. from debian:stretch to debian:bullseye).

For this to work the codename must be in lowercase.

For example, Renovate will offer to upgrade the following Dockerfile layer:

FROM debian:buster

To:

FROM debian:bullseye

Configuring/Disabling

If you wish to make changes that apply to all Docker managers, then add them to the docker config object. This is not foolproof, because some managers like circleci and ansible support multiple datasources that do not inherit from the docker config object.

If you wish to override Docker settings for one particular type of manager, use that manager's config object instead. For example, to disable digest updates for Docker Compose only but leave them for other managers like Dockerfile, you would use this:

{
  "docker-compose": {
    "digest": {
      "enabled": false
    }
  }
}

The following configuration options are applicable to Docker:

Disable all Docker Renovation

Add "docker:disable" to your extends array.

Disable Renovate for only certain Dockerfiles

Add all paths to ignore into the ignorePaths configuration field. e.g.

{
  "extends": ["config:base"],
  "ignorePaths": ["docker/old-files/"]
}

Enable Docker major updates

Add "docker:enableMajor" to your extends array.

Disable digest pinning

Add "default:pinDigestsDisabled" to your extends array.

Automerge digest updates

Add "default:automergeDigest" to your extends array. If you want Renovate to commit directly to your base branch without opening a PR first, add "default:automergeBranchPush" to the extends array.

Registry authentication

There are many different registries, and many ways to authenticate to those registries. We will explain how to authenticate for the most common registries.

DockerHub

Here is an example of configuring a default Docker username/password in config.js. The Docker Hub password is stored in a process environment variable.

module.exports = {
  hostRules: [
    {
      hostType: 'docker',
      username: '<your-username>',
      password: process.env.DOCKER_HUB_PASSWORD,
    },
  ],
};

You can add additional host rules, read the hostRules documentation for more information.

Self-hosted Docker registry

Say you host some Docker images yourself, and use a password to access your self-hosted Docker images. In addition to self-hosting, you also pull images from Docker Hub, without a password. In this example you would configure a specific Docker host like this:

module.exports = {
  hostRules: [
    {
      hostType: 'docker',
      matchHost: 'your.host.io',
      username: '<your-username>',
      password: process.env.SELF_HOSTED_DOCKER_IMAGES_PASSWORD,
    },
  ],
};

Google Container Registry / Google Artifact Registry

Using long-lived service account credentials

To access the Google Container Registry (deprecated) or the Google Artifact Registry, use the JSON service account with Basic authentication, and use the:

  • _json_key as username
  • full Google Cloud Platform service account JSON as password

To avoid JSON-in-JSON wrapping, which can cause problems, encode the JSON service account beforehand.

Google Container Registry does not natively support _json_key_base64 and a base64 encoded service account. Google Artifact Registry supports _json_key_base64 and a base64 encoded service account natively. If all your dependencies are on the Google Artifact Registry, you can base64 encode and use the service account directly:

  1. Download your JSON service account and store it on your machine. Make sure that the service account has read (and only read) permissions to your artifacts
  2. Base64 encode the service account credentials by running cat service-account.json | base64
  3. Add the encoded service account to your configuration file

  4. If you want to add it to your self-hosted configuration file:

    {
      "hostRules": [
        {
          "matchHost": "europe-docker.pkg.dev",
          "authType": "Basic",
          "username": "_json_key_base64",
          "password": "<base64 service account>"
        }
      ]
    }
    
  5. If you want to add it to your repository Renovate configuration file, encrypt it and then add it:

    {
      "hostRules": [
        {
          "matchHost": "europe-docker.pkg.dev",
          "authType": "Basic",
          "username": "_json_key_base64",
          "encrypted": {
            "password": "<encrypted base64 service account>"
          }
        }
      ]
    }
    

If you have dependencies on Google Container Registry (and Artifact Registry) you need to use _json_key and a slightly different encoding:

  1. Download your JSON service account and store it on your machine. Make sure that the service account has read (and only read) permissions to your artifacts
  2. Open the file and prefix the content with _json_key:. The file should look like this:
_json_key:{
  "type": "service_account",
  "project_id": "sample-project",
  "private_key_id": "5786ff7e615522b932a2a37b4a6f9645c4316dbd",
  "private_key": "-----BEGIN PRIVATE KEY-----\nMIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQDaOkxZut9uDUHV\n...\n/PWs0Wa2z5+IawMD7nO63+b6\n-----END PRIVATE KEY-----\n",
  "client_email": "renovate-lookup@sample-project.iam.gserviceaccount.com",
  "client_id": "115429165445403928973",
  "auth_uri": "https://accounts.google.com/o/oauth2/auth",
  "token_uri": "https://oauth2.googleapis.com/token",
  "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
  "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/renovate-lookup%40sample-project.iam.gserviceaccount.com"
}
  1. Base64 encode the prefixed service account credentials by running cat prefixed-service-account.json | base64
  2. Add the prefixed and encoded service account to your configuration file

  3. If you want to add it to your self-hosted configuration file:

    {
      "hostRules": [
        {
          "matchHost": "europe-docker.pkg.dev",
          "authType": "Basic",
          "token": "<base64 prefixed service account>"
        }
      ]
    }
    
  4. If you want to add it to your repository Renovate configuration file, encrypt it and then add it:

    {
      "hostRules": [
        {
          "matchHost": "europe-docker.pkg.dev",
          "authType": "Basic",
          "encrypted": {
            "token": "<encrypted base64 prefixed service account>"
          }
        }
      ]
    }
    
Using short-lived access tokens

Assume you are running GitLab CI in the Google Cloud, and you are storing your Docker images in the Google Container Registry (GCR).

Access to the GCR uses Bearer token based authentication. This token can be obtained by running gcloud auth print-access-token, which requires the Google Cloud SDK to be installed.

The token expires after 60 minutes so you cannot store it in a variable for subsequent builds (like you can with RENOVATE_TOKEN).

When running Renovate in this context the Google access token must be retrieved and injected into the hostRules configuration just before Renovate is started.

This documentation gives a few hints on a possible way to achieve this end result.

The basic approach is that you create a custom image and then run Renovate as one of the stages of your project. To make this run independent of any user you should use a Project Access Token (with Scopes: api, read_api and write_repository) for the project and use this as the RENOVATE_TOKEN variable for GitLab CI. See also the renovate-runner repository on GitLab where .gitlab-ci.yml configuration examples can be found.

To get access to the token a custom Renovate Docker image is needed that includes the Google Cloud SDK. The Dockerfile to create such an image can look like this:

FROM renovate/renovate:32.159.1
# Include the "Docker tip" which you can find here https://cloud.google.com/sdk/docs/install
# under "Installation" for "Debian/Ubuntu"
RUN ...

For Renovate to access the Google Container Registry (GCR) it needs the current Google Access Token. The configuration fragment to do that looks something like this:

hostRules: [
  {
    matchHost: 'eu.gcr.io',
    token: 'MyReallySecretTokenThatExpiresAfter60Minutes',
  },
];

One way to provide the short-lived Google Access Token to Renovate is by generating these settings into a config.js file from within the .gitlab-ci.yml right before starting Renovate:

script:
  - 'echo "module.exports = { hostRules: [ { matchHost: ''eu.gcr.io'', token: ''"$(gcloud auth print-access-token)"'' } ] };" > config.js'
  - renovate $RENOVATE_EXTRA_FLAGS