fix(docs): Add GitOps / Argo CD documentation

docs/enhanced-configuration/gitops.md

@@ -0,0 +1,55 @@
+<!--
+SPDX-FileCopyrightText: 2024 Zentrum für Digitale Souveränität der Öffentlichen Verwaltung (ZenDiS) GmbH
+SPDX-License-Identifier: Apache-2.0
+-->
+
+<h1>GitOps Deployment</h1>
+
+<!-- TOC -->
+* [Considerations](#considerations)
+* [ArgoCD](#argocd)
+  * [Option 1: Use YAML manifests](#option-1-use-yaml-manifests)
+  * [Option 2: Helmfile plugin](#option-2-helmfile-plugin)
+<!-- TOC -->
+
+The recommended deployment method for openDesk is via Helmfile. This can be done "by hand", via CI/CD (Gitlab) or using
+the [GitOps](https://about.gitlab.com/topics/gitops/) approach with tools like [Argo CD](https://argoproj.github.io/cd/).
+
+This documentation will use Argo CD to explain how to deploy openDesk GitOps-style.
+
+# Considerations
+
+- openDesk consists of multiple applications which have to be deployed in order.
+- During upgrades, migrations have to run before and after applications.
+
+# ArgoCD
+
+We are continuously improving our Argo CD support, please share you experience with Argo CD deployments e.g. by [creating
+at ticket](https://gitlab.opencode.de/bmi/opendesk/deployment/opendesk/-/issues).
+
+There are two options to deploy openDesk via Argo CD described in the following sections.
+
+## Option 1: Use YAML manifests
+
+This option requires a preprocessing step before using Argo CD. This step requires you to compile the Helmfile based
+deployment into Kubernetes YAML manifest, to do so you need to execute the helmfile binary:
+
+```shell
+helmfile template > opendesk.yaml
+```
+
+References:
+- [Helmfile CLI documentation](https://helmfile.readthedocs.io/en/latest/#cli-reference)
+- [Generate K8s YAML Manifests for openDesk](https://gitlab.opencode.de/bmi/opendesk/deployment/options/generate-k8s-yaml-manifests)
+
+Afterwards, you can use the resulting manifests within an standard Argo CD workflow.
+
+## Option 2: Helmfile plugin
+
+It is possible to deploy openDesk via Argo CD with community developed
+[Helmfile plugin](https://github.com/travisghansen/argo-cd-helmfile).
+
+You can find an example for this approach in the
+[Argo CD Deployments](https://gitlab.opencode.de/bmi/opendesk/deployment/options/argocd-deploy) repository.
+It contains an example Helm chart (`opendesk-parent`) to create Argo CD Applications via a Helm chart (`opendesk`)
+according to `app of apps pattern` and is using sync waves to follow dependencies.

docs/enhanced-configuration/idp-federation.md

@@ -7,6 +7,7 @@ SPDX-License-Identifier: Apache-2.0
 
 <!-- TOC -->
 * [Context](#context)
+* [References](#references)
 * [Prerequisites](#prerequisites)
   * [User accounts](#user-accounts)
   * [External IdP with OIDC](#external-idp-with-oidc)
@@ -24,6 +25,15 @@ Most organizations already have an Identity and Access Management (IAM) system w
 
 This document shows how to configure your organization's IdP and the openDesk IdP to support account federation with openDesk single sign-on based on your organization's login.
 
+# References
+
+We would like to list successful IdP federation scenarios, so we are also happy about input from the community:
+
+| External IdP                                                        | last openDesk version tested |
+| ------------------------------------------------------------------- | ---------------------------- |
+| [EU Login](https://webgate.ec.europa.eu/cas/userdata/myAccount.cgi) | v0.9.0                       |
+| [ProConnect](https://www.proconnect.gouv.fr/)                       | v0.9.0                       |
+
 # Prerequisites
 
 ## User accounts