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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.

Required Fields

The first two required fields are fileMatch and matchStrings:

  • fileMatch 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

Before Renovate can look up a dependency and decide about updates, it needs this information about each dependency:

  • The dependency's name
  • Which datasource to use: npm, Docker, GitHub tags, and so on. For how to format this references see datasource overview
  • Which version scheme to use: defaults to semver-coerced, but you may set another value like pep440. Supported versioning schemes can be found in the versioning overview

Configuration-wise, it works like this:

  • You must capture the currentValue of the dependency in a named capture group
  • You must have either a depName or packageName capture group, or use on of the respective template fields ( depNameTemplate and packageNameTemplate )
  • You must have either a datasource capture group or a datasourceTemplate config field
  • You can optionally have a depType capture group or a depTypeTemplate config field
  • You can optionally have a versioning capture group or a versioningTemplate config field. If neither are present, Renovate will use semver-coerced as the default
  • You can optionally have an extractVersion capture group or an extractVersionTemplate config field
  • You can optionally have a currentDigest capture group
  • You can optionally have 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
  • You can optionally have an indentation capture group. It must be either empty or whitespace only, otherwise it 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.

Take this Dockerfile as an example:

FROM node:12
RUN curl -o- -L | bash -s -- --version ${YARN_VERSION}

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

If you're looking for an online regex testing tool that supports capture groups, try You must select the ECMAScript (JavaScript) flavor of regex. Be aware that 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.

The regex manager uses RE2 which does not support backreferences and lookahead assertions. The regex manager matches are done per-file and not per-line, you should be aware when using the ^ and/or $ regex assertions.

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",
      "fileMatch": ["^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
# renovate: datasource=github-releases depName=composer packageName=composer/composer
# renovate: datasource=docker packageName=docker versioning=docker
# renovate: datasource=npm packageName=yarn

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",
      "fileMatch": ["(^|/|\\.)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",
      "fileMatch": ["(^|/)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",
      "fileMatch": [".*y[a]?ml$"],
      "matchStringsStrategy": "combination",
      "matchStrings": [
      "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'

Open items

The below list of features and bugs were current when this page was generated on June 20, 2024.

Feature requests

  • Support registryAliases for customManagers #28699
  • Dedupe regex managers after resolution #25132
  • Allow naming of regex managers #21760
  • initial digest pinning for regex manager #10993

Bug reports

  • Generic regex managers break Digest pinning PRs if using docker datasource with digest pinning enabled #24942
  • Regex Manager depName mismatch when depName contains the value being updated #24559