Merge pull request #22 from cnieg/add_dockerhub_readme

Add a file and a job to update our docker hub description

.github/workflows/release.yml

@@ -80,3 +80,13 @@ jobs:
         with:
           generateReleaseNotes: true
           tag: ${{ env.semVer }}
+          makeLatest: "true"
+
+    - name: Docker Hub Description
+      uses: peter-evans/dockerhub-description@v4
+      with:
+        username: ${{ secrets.DOCKER_USERNAME }}
+        password: ${{ secrets.DOCKER_PASSWORD }}
+        repository: cnieg/gitlab-tokens-exporter
+        readme-filepath: ./README_dockerhub.md
+        short-description: ${{ github.event.repository.description }}

README_dockerhub.md

@@ -0,0 +1,27 @@
+# Gitlab tokens prometheus exporter
+
+Exports the number of days before expiration of gitlab tokens as Prometheus metrics
+
+## Getting Started
+
+The following environment variables are mandatory :
+
+```
+GITLAB_BASEURL=<gitlab hostname>
+GITLAB_TOKEN=<gitlab authentication token>
+```
+
+Optional environment variables :
+```
+DATA_REFRESH_HOURS=6 (should be > 0 and <= 24 or else, it will be set to the default value: 6)
+```
+
+You can launch an instance using the following docker command :
+```
+docker run -it --rm -e "GITLAB_BASEURL=<gitlab hostname>" -e "GITLAB_TOKEN=<gitlab authentication token>" cnieg/gitlab-tokens-exporter:latest
+```
+
+## Known limitations
+
+When launching the exporter, it will first get infos on **all** the gitlab tokens, so it can take some time depending on the number of projects to scan.
+The exporter returns `204 No Content` until the first scan is done.