feat(regexp): support grafana dashboards

README.md

@@ -2,3 +2,86 @@
 
 This project contains configuration presets for renovate, a bot to update dependencies. These presets can be integrated
 into the `renovate.json` of the respective git project using the `extends` attribute.
+
+## How to
+
+### regexp
+
+Contains regular expressions to search for inline configurations of renovate. For example in `.sh` or `Makefile` files.
+A regular expression is applied to extract an inline configuration. The regular expression is really complex. For this
+reason, it is reproduced on [regexp101.com](https://regex101.com/r/H7bNqj) for the purpose of standardization.
+
+Here are further examples how to use the regexp inline configuration.
+
+#### container image version
+
+A shell script that executes a container image. The version of the container image should be maintained in the shell
+script.
+
+```bash
+#!/bin/bash
+
+VERSION="3.21.1" # renovate: datasource=docker registryUrl=https://docker.io depName=library/alpine
+
+docker run --rm --entrypoint /bin/sh docker.io/library/alpine:${VERSION} -c "echo foo bar"
+```
+
+#### github releases and tags
+
+A PKGBUILD file for the Arch Linux User Repository (AUR) whose version is to be updated based on GitHub releases.
+
+> [!NOTE]
+> The concrete example can be found in [volker-raschek/rpm-builder-aur](https://github.com/volker-raschek/rpm-builder-pkg/blob/master/PKGBUILD#L4).
+
+```sh
+pkgname=rpm-builder
+pkgver=v0.8.1 # renovate: datasource=github-releases depName=Richterrettich/rpm-builder
+pkgrel=1
+```
+
+#### extract version
+
+The version of Postfixadmin is maintained in a Makefile. As source should be used github tags, but their tags does not
+follow an official standard like PEP404 or semver. They use `postfixadmin-<semver>`. The `extractVersion` pattern is
+used to extract the version of the git tag.
+
+> [!NOTE]
+> The concrete example can be found in [volker-raschek/postfixadmin-docker](https://github.com/volker-raschek/postfixadmin-docker/blob/324d532b696bf7f6007375bb3601d204ad5f4e45/Makefile#L3)
+
+```Makefile
+# POSTFIXADMIN_VERSION
+POSTFIXADMIN_VERSION?=3.3.15 # renovate: datasource=github-tags depName=postfixadmin/postfixadmin extractVersion='postfixadmin-(?<version>\d+\.\d+\.\d+)$'
+```
+
+#### grafana-dashboards
+
+Grafana supports importing of dashboards via its sidecar container in kubernetes environments. The import can be
+specified via the `values.yaml` file of kube-prometheus stack. The `revision` must be updated, if the maintainer of the
+dashboard has released a new revision. This can be automatically be updated via renovate. Below is an excerpt of the
+`values.yaml` file.
+
+> [!NOTE]
+> The datasource `custom.grafana-dashboards` is a custom implemented datasource. The renovate project does not support
+> updating grafana dashboards by default, because the API does not provide the required minimum set of attributes.
+>
+> Further information can be found on the discussion [Grafana Dashboard
+> revisions](https://github.com/renovatebot/renovate/discussions/16624#discussioncomment-3169468).
+
+The `gnetId` and `revision` must be extracted from [Grafana.com](https://grafana.com/grafana/dashboards/).
+
+> [!IMPORTANT]
+> The defined regexp in `regexp.json` does not support that `depName` contains any spaces!
+
+```yaml
+grafana:
+  dashboards:
+    default:
+      1860-node-exporter-full:
+        gnetId: 1860
+        revision: 31 # renovate: datasource=custom.grafana-dashboards depName='Node-Exporter-Full' packageName=1860 versioning='regex:^(?<major>\d+)$'
+        datasource: Prometheus
+      15760-kubernetes-views-pods:
+        gnetId: 15760
+        revision: 19 # renovate: datasource=custom.grafana-dashboards depName='Kubernetes-Views-Pods' packageName=15760 versioning='regex:^(?<major>\d+)$'
+        datasource: Prometheus
+```

grafana-dashboards.json

@@ -0,0 +1,12 @@
+{
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+  "customDatasources": {
+    "grafana-dashboards": {
+      "defaultRegistryUrlTemplate": "https://grafana.com/api/dashboards/{{ packageName }}",
+      "format": "json",
+      "transformTemplates": [
+        "{\"releases\": [{\"version\": $string(revision)}], \"homepage\": \"https://grafana.com/dashboards/$string(id)\", \"sourceUrl\": \"https://grafana.com/dashboards/$string(id)\"}"
+      ]
+    }
+  }
+}

regexp.json

@@ -1,14 +1,5 @@
 {
   "$schema": "https://docs.renovatebot.com/renovate-schema.json",
-  "customDatasources": {
-    "grafana-dashboards": {
-      "defaultRegistryUrlTemplate": "https://grafana.com/api/dashboards/{{ packageName }}",
-      "format": "json",
-      "transformTemplates": [
-        "{\"releases\": [{\"version\": $string(revision)}], \"homepage\": \"https://grafana.com/dashboards/$string(id)\", \"sourceUrl\": \"https://grafana.com/dashboards/$string(id)\"}"
-      ]
-    }
-  },
   "customManagers": [
     {
       "customType": "regex",