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Custom Manager Support using Regex

Categories: custom

With customManagers using regex you can configure Renovate so it finds dependencies that are not detected by its other built-in package managers.

Renovate supports the ECMAScript (JavaScript) flavor of regex.

Renovate uses the uhop/node-re2 package that provides bindings for google/re2. Read about uhop/node-re2's limitations in their readme. The regex manager is unique in Renovate because:

  • It is configurable via regex named capture groups
  • It can extract any datasource
  • By using the customManagers config, you can create multiple "regex managers" for the same repository

We have additional Handlebars helpers to help you perform common transformations on the regex manager's template fields. Also read the documentation for the customManagers config option.

If you have limited managers to run within enabledManagers config option, you need to add "custom.regex" to the list.

Required Fields

The first two required fields are managerFilePatterns and matchStrings:

  • managerFilePatterns works the same as any manager
  • matchStrings is a regex custom manager concept and is used for configuring a regular expression with named capture groups

Information that Renovate needs about the dependency

Before Renovate can look up a dependency and decide about updates, it must have this info about each dependency:

Info type Required Notes Docs
Name of the dependency Yes
datasource Yes Example datasources: npm, Docker, GitHub tags, and so on. Supported datasources
Version scheme to use. Defaults to semver-coerced. Yes You may set another version scheme, like pep440. Supported versioning schemes

Required capture groups

You must:

  • Capture the currentValue of the dependency in a named capture group
  • Set a depName or packageName capture group. Or use a template field: depNameTemplate and packageNameTemplate
  • Set a datasource capture group, or a datasourceTemplate config field

Optional capture groups

You may use any of these items:

  • A depType capture group, or a depTypeTemplate config field
  • A versioning capture group, or a versioningTemplate config field. If neither are present, Renovate defaults to semver-coerced
  • An extractVersion capture group, or an extractVersionTemplate config field
  • A currentDigest capture group
  • A registryUrl capture group, or a registryUrlTemplate config field. If it's a valid URL, it will be converted to the registryUrls field as a single-length array
  • An indentation capture group. It must be either empty, or whitespace only (otherwise indentation will be reset to an empty string)

Regular Expression Capture Groups

To be effective with the regex manager, you should understand regular expressions and named capture groups. But enough examples may compensate for lack of experience.

Example Dockerfile
FROM node:12
ENV YARN_VERSION=1.19.1
RUN curl -o- -L https://yarnpkg.com/install.sh | bash -s -- --version ${YARN_VERSION}

You would need to capture the currentValue with a named capture group, like this: ENV YARN_VERSION=(?<currentValue>.*?)\\n.

To update a version string multiple times in a line: use multiple matchStrings, one for each occurrence.

Full Renovate .json5 config
{
  customManagers: [
    {
      customType: 'regex',
      managerFilePatterns: ['file-you-want-to-match'],
      matchStrings: [
        // for the version on the left part, ignoring the right
        '# renovate: datasource=(?<datasource>.*?) depName=(?<depName>.*?)( versioning=(?<versioning>.*?))?\\s\\S+?:(?<currentValue>\\S+)\\s+\\S+:.+',
        // for the version on the right part, ignoring the left
        '# renovate: datasource=(?<datasource>.*?) depName=(?<depName>.*?)( versioning=(?<versioning>.*?))?\\s\\S+?:\\S+\\s+\\S+:(?<currentValue>\\S+)',
      ],
      versioningTemplate: '{{#if versioning}}{{{versioning}}}{{else}}semver{{/if}}',
    },
  ],
}
Example of how the file-you-want-to-match could look like
# renovate: datasource=github-tags depName=org/repo versioning=loose
something:4.7.2    something-else:4.7.2

Online regex testing tool tips

If you're looking for an online regex testing tool that supports capture groups, try regex101.com. You must select the ECMAScript (JavaScript) flavor of regex. Backslashes ('\') of the resulting regex have to still be escaped e.g. \n\s --> \\n\\s. You can use the Code Generator in the sidebar and copy the regex in the generated "Alternative syntax" comment into JSON.

Renovate's regex differs from the online tools

The regex manager uses RE2 which does not support backreferences and lookahead assertions.

The regex manager matches are done per-file, not per-line! This means the ^ and $ regex assertions only match the beginning and end of the entire file. If you need to match line boundaries you can use (?:^|\r\n|\r|\n|$).

Configuration templates

In many cases, named capture groups alone aren't enough and you'll need to give Renovate more information so it can look up a dependency. Continuing the above example with Yarn, here is the full Renovate config:

{
  "customManagers": [
    {
      "customType": "regex",
      "managerFilePatterns": ["/^Dockerfile$/"],
      "matchStrings": ["ENV YARN_VERSION=(?<currentValue>.*?)\\n"],
      "depNameTemplate": "yarn",
      "datasourceTemplate": "npm"
    }
  ]
}

Advanced Capture

Say your Dockerfile has many ENV variables that you want to keep up-to-date. But you don't want to write a regex custom manager rule for each variable. Instead you enhance your Dockerfile like this:

# renovate: datasource=github-tags depName=node packageName=nodejs/node versioning=node
ENV NODE_VERSION=20.10.0
# renovate: datasource=github-releases depName=composer packageName=composer/composer
ENV COMPOSER_VERSION=1.9.3
# renovate: datasource=docker packageName=docker versioning=docker
ENV DOCKER_VERSION=19.03.1
# renovate: datasource=npm packageName=yarn
ENV YARN_VERSION=1.19.1

This Dockerfile is meant as an example, your Dockerfile may be a lot bigger.

You could configure Renovate to update the Dockerfile like this:

{
  "customManagers": [
    {
      "customType": "regex",
      "description": "Update _VERSION variables in Dockerfiles",
      "managerFilePatterns": [
        "/(^|/|\\.)Dockerfile$/",
        "/(^|/)Dockerfile\\.[^/]*$/"
      ],
      "matchStrings": [
        "# renovate: datasource=(?<datasource>[a-z-]+?)(?: depName=(?<depName>.+?))? packageName=(?<packageName>.+?)(?: versioning=(?<versioning>[a-z-]+?))?\\s(?:ENV|ARG) .+?_VERSION=(?<currentValue>.+?)\\s"
      ]
    }
  ]
}

We could drop the versioningTemplate because Renovate defaults to semver-coerced versioning. But we included the versioningTemplate config option to show you why we call these fields templates: because they are compiled using Handlebars and so can be composed from values you collect in named capture groups.

You should use triple brace {{{ }}} templates like {{{versioning}}} to be safe. This is because Handlebars escapes special characters with double braces (by default).

By adding renovate: datasource= and depName= comments to the Dockerfile you only need one customManager instead of four. The Dockerfile is documented better as well.

The syntax in the example is arbitrary, and you can set your own syntax. If you do, update your matchStrings regex!

For example the appVersion property in a Chart.yaml of a Helm chart is always referenced to an Docker image. In such scenarios, some values can be hard-coded. For example:

apiVersion: v2
name: amazon-eks-pod-identity-webhook
description: A Kubernetes webhook for pods that need AWS IAM access
version: 1.0.3
type: application
# renovate: image=amazon/amazon-eks-pod-identity-webhook
appVersion: 'v0.4.0'

Using the customManagers below, Renovate looks for available Docker tags of the image amazon/amazon-eks-pod-identity-webhook.

{
  "customManagers": [
    {
      "customType": "regex",
      "datasourceTemplate": "docker",
      "managerFilePatterns": ["/(^|/)Chart\\.yaml$/"],
      "matchStrings": [
        "#\\s?renovate: image=(?<depName>.*?)\\s?appVersion:\\s?\\'?(?<currentValue>[\\w+\\.\\-]*)'"
      ]
    }
  ]
}

Using customManager to update the dependency name in addition to version

Updating gitlab-ci include dep names

You can use the regex manager to update the depName and the version. This can be handy when the location of files referenced in gitlab-ci includes: fields has changed.

You may need to set a second matchString for the new name to ensure the regex manager can detect the new value. For example:

{
  "customManagers": [
    {
      "customType": "regex",
      "managerFilePatterns": ["/.*y[a]?ml$/"],
      "matchStringsStrategy": "combination",
      "matchStrings": [
        "['\"]?(?<depName>/pipeline-fragments/fragment-version-check)['\"]?\\s*ref:\\s['\"]?(?<currentValue>[\\d-]*)['\"]?",
        "['\"]?(?<depName>pipeline-solutions/gitlab/fragments/fragment-version-check)['\"]?\\s*ref:\\s['\"]?(?<currentValue>[\\d-]*)['\"]?"
      ],
      "depNameTemplate": "pipeline-solutions/gitlab/fragments/fragment-version-check",
      "autoReplaceStringTemplate": "'{{{depName}}}'\n    ref: {{{newValue}}}",
      "datasourceTemplate": "gitlab-tags",
      "versioningTemplate": "gitlab-tags"
    }
  ]
}

The config above will migrate:

- project: 'pipeline-fragments/docker-lint'
  ref: 2-4-0
  file: 'ci-include-docker-lint-base.yml'

To this:

- project: 'pipeline-solutions/gitlab/fragments/docker-lint'
  ref: 2-4-1
  file: 'ci-include-docker-lint-base.yml'