add testing docker image for local tests

Dockerfile.dev

@@ -0,0 +1,21 @@
+FROM golang:1.23-alpine AS build-env
+
+RUN apk add --update --no-cache make bash mailcap
+
+WORKDIR /app
+COPY . .
+
+RUN make build
+
+FROM gcr.io/distroless/static-debian12
+
+LABEL maintainer="The Perses Authors <[email protected]>"
+
+USER nobody
+
+COPY --from=build-env --chown=nobody:nobody /app/bin/manager  /bin/manager
+COPY --chown=nobody:nobody LICENSE                            /LICENSE
+COPY --from=build-env --chown=nobody:nobody                   /etc/mime.types /etc/mime.types
+
+EXPOSE     8080
+ENTRYPOINT [ "/bin/manager" ]

Makefile

@@ -153,6 +153,10 @@ run: manifests generate fmt vet ## Run a controller from your host.
 image-build: build test ## Build docker image with the manager.
 	${CONTAINER_RUNTIME} build -f Dockerfile -t ${IMG} .
 
+.PHONY: test-image-build
+test-image-build: test ## Build a testing docker image with the manager.
+	${CONTAINER_RUNTIME} build -f Dockerfile.dev -t ${IMG} .
+
 .PHONY: image-push
 image-push: ## Push docker image with the manager.
 	${CONTAINER_RUNTIME} push ${IMG}

README.md

@@ -4,8 +4,10 @@ An operator to install [Perses](https://github.com/perses/perses) in a k8s clust
 
 ## Getting Started
 
-You’ll need a Kubernetes cluster to run against. You can use [KIND](https://sigs.k8s.io/kind) to get a local cluster for testing, or run against a remote cluster.
+You’ll need: 
+- a Kubernetes cluster to run against. You can use [KIND](https://sigs.k8s.io/kind) to get a local cluster for testing, or run against a remote cluster.
 **Note:** Your controller will automatically use the current context in your kubeconfig file (i.e. whatever cluster `kubectl cluster-info` shows).
+- [kubectl](https://kubernetes.io/docs/tasks/tools/#kubectl) installed and configured to use your cluster.
 
 ### Running on the cluster
 
@@ -20,13 +22,13 @@ make install
 kubectl apply -k config/samples
 ```
 
-3. Usint the the location specified by `IMG`, build and push the image to the registry, then deploy the controller to the cluster:
+3. Using the the location specified by `IMG`, build a testing image and push it to the registry, then deploy the controller to the cluster:
 
 ```sh
-IMG=<some-registry>/perses-operator:tag make image-build image-push deploy
+IMG=<some-registry>/perses-operator:tag make test-image-build image-push deploy
 ```
 
-5. Access the Perses UI at `http://localhost:8080` by port-forwarding the service:
+4. Port forward the service so you can access the Perses UI at `http://localhost:8080`:
 
 ```sh
 kubectl port-forward svc/perses-sample 8080:8080