Add link to dev guide

Author: stefanprodan

README.md

@@ -6,168 +6,6 @@ Example consumer of the GitOps Toolkit Source APIs.
 
 ![](https://raw.githubusercontent.com/fluxcd/toolkit/master/docs/_files/source-controller.png)
 
-## Watch Git repositories
+## Guides
 
-The [GitRepositoryWatcher](controllers/gitrepository_watcher.go) controller does the following:
-
-* subscribes to `GitRepository` events
-* detects when the Git revision changes
-* downloads and extracts the source artifact
-* write to stdout the extracted file names
-
-```go
-// GitRepositoryWatcher watches GitRepository objects for revision changes
-type GitRepositoryWatcher struct {
-	client.Client
-	Log    logr.Logger
-	Scheme *runtime.Scheme
-}
-
-// +kubebuilder:rbac:groups=source.fluxcd.io,resources=gitrepositories,verbs=get;list;watch
-// +kubebuilder:rbac:groups=source.fluxcd.io,resources=gitrepositories/status,verbs=get
-
-func (r *GitRepositoryWatcher) Reconcile(req ctrl.Request) (ctrl.Result, error) {
-	// set timeout for the reconciliation
-	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
-	defer cancel()
-
-	// get source object
-	var repository sourcev1.GitRepository
-	if err := r.Get(ctx, req.NamespacedName, &repository); err != nil {
-		return ctrl.Result{}, client.IgnoreNotFound(err)
-	}
-
-	log := r.Log.WithValues(strings.ToLower(repository.Kind), req.NamespacedName)
-	log.Info("New revision detected", "revision", repository.Status.Artifact.Revision)
-
-	// create tmp dir
-	tmpDir, err := ioutil.TempDir("", repository.Name)
-	if err != nil {
-		return ctrl.Result{}, fmt.Errorf("failed to create temp dir, error: %w", err)
-	}
-	defer os.RemoveAll(tmpDir)
-
-	// download and extract artifact
-	summary, err := r.fetchArtifact(ctx, repository, tmpDir)
-	if err != nil {
-		log.Error(err, "unable to fetch artifact")
-		return ctrl.Result{}, err
-	}
-	log.Info(summary)
-
-	// list artifact content
-	files, err := ioutil.ReadDir(tmpDir)
-	if err != nil {
-		return ctrl.Result{}, fmt.Errorf("faild to list files, error: %w", err)
-	}
-
-	// do something with the artifact content
-	for _, f := range files {
-		log.Info("Processing " + f.Name())
-	}
-
-	return ctrl.Result{}, nil
-}
-
-func (r *GitRepositoryWatcher) SetupWithManager(mgr ctrl.Manager) error {
-	return ctrl.NewControllerManagedBy(mgr).
-		For(&sourcev1.GitRepository{}).
-		WithEventFilter(GitRepositoryRevisionChangePredicate{}).
-		Complete(r)
-}
-```
-
-Source code:
-
-* controller [gitrepository_watcher.go](controllers/gitrepository_watcher.go)
-* predicate [gitrepository_predicate.go](controllers/gitrepository_predicate.go)
-* initialisation [main.go](main.go)
-
-### Prerequisites
-
-* go >= 1.13
-* kubebuilder >= 2.3
-* kind >= 0.8
-
-Clone source watcher repo:
-
-```sh
-git clone https://github.com/stefanprodan/source-watcher
-cd source-watcher
-```
-
-Build the controller:
-
-```sh
-make
-```
-
-### Install the GitOps toolkit
-
-Create a cluster for testing:
-
-```sh
-kind create cluster --name testing
-```
-
-Install the toolkit CLI:
-
-```sh
-curl -s https://toolkit.fluxcd.io/install.sh | sudo bash
-```
-
-Install the toolkit controllers:
-
-```sh
-tk install
-```
-
-### Run the controller
-
-Port forward to source controller artifacts server:
-
-```sh
-kubectl -n gitops-system port-forward svc/source-controller 8080:80
-```
-
-Export the local address as `SOURCE_HOST`:
-
-```sh
-export SOURCE_HOST=localhost:8080
-```
-
-Run the controller:
-
-```sh
-make run
-```
-
-Create a Git source:
-
-```sh
-tk create source git test \
---url=https://github.com/stefanprodan/podinfo \
---tag=4.0.0
-```
-
-The source watcher should log the revision:
-
-```console
-New revision detected   {"gitrepository": "gitops-system/test", "revision": "4.0.0/ab953493ee14c3c9800bda0251e0c507f9741408"}
-Extracted tarball into /var/folders/77/3y6x_p2j2g9fspdkzjbm5_s40000gn/T/test292235827: 123 files, 29 dirs (32.603415ms)
-Processing files...
-```
-
-Change the git tag:
-
-```sh
-tk create source git test \
---url=https://github.com/stefanprodan/podinfo \
---tag=4.0.1
-```
-
-The source watcher should log the new revision:
-
-```console
-New revision detected   {"gitrepository": "gitops-system/test", "revision": "4.0.1/113360052b3153e439a0cf8de76b8e3d2a7bdf27"}
-```
+* [Watching for source changes](https://toolkit.fluxcd.io/dev-guides/source-watcher/)