How to configure custom manager to detect dependency version in Dockerfile and update dependency

[tobias-lippert]

What would you like help with?

I would like help with my configuration

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Self-hosted

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Gitlab 37.320-slim

Please tell us more about your question or problem

I have a repository that contains some Dockerfiles. I want to update the dependencies in one Dockerfile. This works for specified dependencies in the docker file e.g. asciidoctor as desired.
I have one special case where the dependency version is defined as ARG variable in the Dockerfile but the dependency itself is from a maven repository and is specified in a pom.xml file. The version property in the pom.xml is set to a dummy value and overriden with the value from the Dockerfile before mvn install is executed (should be not relevant for Renovate to my understanding). It's also a dependency from a private maven repository but Renovate should at least detect it.

I want to update this dependency using Renovate
Therefore, I've introduced the following config but Renovate doesn't recognize my dependency and according to the docs this should work. So, I assume it's a config mistake on my side.

{
  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
  "extends": [
    "config:base"
  ],
  "internalChecksFilter": "strict",
  "customManagers": [
    {
      "customType": "regex",
      "fileMatch": [
        "^Dockerfile$"
      ],
      "matchStrings": [
        "ARG VERSION=\"(?<currentValue>.*?)\"\\n"
      ],
      "packageNameTemplate": "group-id:artifact-id",
      "depNameTemplate": "group-id:artifact-id",
      "datasourceTemplate": "maven",
      "versioningTemplate": "semver"
    }
  ],
  "includePaths": [
    "path/to/dockerfile"
  ]

Logs (if relevant)

Logs

Debug Logs contain no errors or warnings,

[rarkins]

Your fileMatch and includePaths contradict, for a start

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[tobias-lippert]

Thanks @rarkins - that fixed it.