docs: Add flux example (#187)

Co-authored-by: Giovanni Liva <giovanni.liva@dynatrace.com>

examples/flux/.gitignore

@@ -0,0 +1 @@
+flux-demo

examples/flux/Makefile

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+JAEGER_VERSION ?= v1.38.0
+LFC_NAMESPACE ?= keptn-lifecycle-controller-system
+PODTATO_NAMESPACE ?= podtato-kubectl
+REPO_PATH ?= flux-demo
+REPO_CLUSTER_PATH ?= clusters/demo-cluster
+GITHUB_REPO ?= ""
+GITHUB_BRANCH ?= "main"
+GITHUB_USER ?= ""
+GITHUB_TOKEN ?= ""
+
+
+.PHONY: install
+install: check-repo-url-empty check-github-user-empty check-flux-binary
+	@echo "----------------------------------------"
+	@echo "Preparing your flux repo and set up flux"
+	@echo "----------------------------------------"
+	@echo "(i) Make sure that you have a Personal Access Token prepared for your GitHub account (https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/creating-a-personal-access-token)"
+	@echo "(i) You will need all permissions under repo (according to https://fluxcd.io/flux/installation/#github-and-github-enterprise)"
+	@echo ""
+	@sleep 5
+	flux bootstrap github \
+		--owner=$(GITHUB_USER) \
+		--repository=$(GITHUB_REPO) \
+		--branch=$(GITHUB_BRANCH) \
+		--path=$(REPO_CLUSTER_PATH) \
+		--personal
+	rm -rf $(REPO_CLUSTER_PATH)
+
+	@echo "----------------------------------------"
+	@echo "Cloning your flux repo"
+	@echo "----------------------------------------"
+	git clone $(GITHUB_REPO) $(REPO_PATH)
+
+	@echo "-----------------------------------------------------------------------------"
+	@echo "Flux is prepared, you can find the repo at $(REPO_PATH)"
+	@echo "Then you can proceed with the next step: make manifests <YOUR_REPO_PATH>"
+	@echo "-----------------------------------------------------------------------------"
+
+.PHONY: manifests
+manifests:
+	cp config/flux-config.yaml $(REPO_PATH)/$(REPO_CLUSTER_PATH)
+	cd $(REPO_PATH) && git add . && git commit -m "Add podtatohead manifests" && git push
+
+.PHONY: check-repo-url-empty
+check-repo-url-empty:
+	@if [ $(GITHUB_REPO) == "" ]; then \
+		echo "ERROR: GITHUB_REPO has not been specified"; \
+		exit 1; \
+	fi
+
+.PHONY: check-github-user-empty
+check-github-user-empty:
+	@if [ $(GITHUB_USER) == "" ]; then \
+		echo "ERROR: GITHUB_USER has not been specified"; \
+		exit 1; \
+	fi
+
+.PHONY: check-flux-binary
+check-flux-binary:
+	@if ! command -v flux &> /dev/null; then \
+		echo "ERROR: flux binary not found. Please install flux"; \
+		exit 1; \
+	fi
+
+.PHONY: uninstall
+uninstall: check-flux-binary
+	@echo "----------------------------------------"
+	@echo "Uninstalling flux"
+	@echo "----------------------------------------"
+	flux uninstall

examples/flux/README.md

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+# Use lifecycle-controller together with flux
+
+This tutorial shows how to use the lifecycle-controller together with [Flux](https://fluxcd.io/).
+
+## TL;DR
+* Set up a Personal Access Token according to: https://fluxcd.io/flux/installation/#github-and-github-enterprise
+* Set up Flux and a GitHub repository: `make install GITHUB_REPO=https://github.com/<YOUR_GITHUB_HANDLE>/flux-demo GITHUB_USER=<YOUR_GITHUB_HANDLE> GITHUB_TOKEN=<YOUR_GITHUB_TOKEN>`
+
+* Apply manifests to the Repository: `make manifests`
+* Watch the progress of the deployment using: `kubectl get keptnapplicationversions -n podtato-kubectl`
+  * This might take a while
+
+## Prerequisites
+The Flux CLI should be installed. See [here](https://fluxcd.io/docs/installation/) for more information.
+
+MacOS: `brew install fluxcd/tap/flux`
+bash: `curl -s https://fluxcd.io/install.sh | sudo bash`
+chocolatey: `choco install flux`
+
+## Bootstrap your repository and install flux
+Follow the instructions in the quickstart guide: https://fluxcd.io/docs/get-started/
+
+## Installing the Demo Application
+To install the demo application, you can check in the configuration provided in the config-repository to the repository you created in the previous step.
+
+You can watch the progress of the deployment using:
+> `kubectl get pods -n podtato-kubectl`
+* See that the pods are pending until the pre-deployment tasks have passed
+* Pre-Deployment Tasks are started
+* Pods get scheduled
+
+> `kubectl get keptnworkloadinstances -n podtato-kubectl`
+* Get the current status of the workloads
+* See in which phase your workload deployments are at the moment
+
+> `kubectl get keptnapplicationversions -n podtato-kubectl`
+* Get the current status of the application
+* See in which phase your application deployment is at the moment
+
+After some time all resources should be in a succeeded state. Taking a look on the kustomization resource, you can see that the deployment has been updated to the latest version.
+> `kubectl describe kustomizations.kustomize.toolkit.fluxcd.io podtatohead -n default`

examples/flux/config/flux-config.yaml

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+---
+apiVersion: source.toolkit.fluxcd.io/v1beta2
+kind: GitRepository
+metadata:
+  name: lifecycle-controller
+  namespace: default
+spec:
+  interval: 5m
+  url: https://github.com/keptn-sandbox/lifecycle-controller
+  ref:
+    branch: main
+  ignore: |
+    # exclude all
+    /*
+    # include deploy dir
+    !/examples/podtatohead-deployment
+    
+---
+apiVersion: kustomize.toolkit.fluxcd.io/v1beta2
+kind: Kustomization
+metadata:
+  name: podtatohead
+  namespace: default
+spec:
+  interval: 15m
+  path: "./examples/podtatohead-deployment"
+  prune: true
+  sourceRef:
+    kind: GitRepository
+    name: lifecycle-controller

examples/podtatohead-deployment/post-deployment-tasks.yaml

@@ -2,6 +2,7 @@ apiVersion: lifecycle.keptn.sh/v1alpha1
 kind: KeptnTaskDefinition
 metadata:
   name: post-deployment-hello
+  namespace: podtato-kubectl
 spec:
   function:
     inline: