chore: add Tiltfile for easier local development and testing

.dockerignore

@@ -0,0 +1,4 @@
+**/*
+!pkg
+!go.*
+!cmd

.gitignore

@@ -5,4 +5,8 @@ flagger-k6-webhook
 .vscode
 
 # CI
-.drone/temp.yml
+.drone/temp.yml
+
+# Tilt setup
+.cache
+dev-workload.yml

Dockerfile

@@ -3,7 +3,7 @@ FROM golang:1.23.4-alpine AS build
 RUN mkdir /app
 WORKDIR /app
 COPY . /app/
-RUN CGO_ENABLED=0 GOOS=linux go build -ldflags '-extldflags "-static"' -o /app/flagger-k6-webhook cmd/main.go
+RUN --mount=type=cache,target=/go/pkg/mod CGO_ENABLED=0 GOOS=linux go build -ldflags '-extldflags "-static"' -o /app/flagger-k6-webhook cmd/main.go
 
 FROM alpine:3.21
 

README.md

@@ -100,3 +100,28 @@ By default, that limit is set to 1,000 *parallel* k6 processes which can be conf
 If a new test request is received while the limit is reached, the request will be rejected with a HTTP 429 status.
 The response also includes a `Retry-After` header that should be respected by the client.
 
+## Local development
+
+For local development we also ship a [Tiltfile](https://tilt.dev) so that, combined with [kind][] and [ctrptl][], you can test many scenarios locally:
+
+```
+# Prepare a demo host
+sudo echo "127.0.0.1  demo.localhost" >> /etc/hosts
+
+# Copy the provided dummy workload to the setup
+cp dev-workload.dist.yml dev-workload.yml
+
+# Create a kind cluster
+ctlptl create cluster kind --registry=ctlptl-registry
+
+# Start up tilt
+tilt up
+```
+
+This will set up Traefik as gateway and export the port 8080.
+After a short while you should see a standard nginx start page when curling `http://demo.local:8080`.
+
+The easiest way to now test a canary is to update the nginx version in the dev workload.
+
+[kind]: https://kind.sigs.k8s.io/
+[ctlptl]: https://github.com/tilt-dev/ctlptl

Tiltfile

@@ -0,0 +1,92 @@
+if k8s_context() != 'kind-kind':
+  fail("failing early to avoid overwriting prod")
+
+
+def name(res):
+    return res['metadata']['name']
+
+
+def download_to_cache(url, filename):
+    full_path = os.path.join('.cache', filename)
+    if not os.path.exists(full_path):
+        local('curl --create-dirs --location --output %s %s' % (full_path, url))
+    return full_path
+
+
+load('ext://secret', 'secret_from_dict')
+load('ext://helm_resource', 'helm_resource', 'helm_repo')
+
+helm_repo('helm-traefik',  'https://traefik.github.io/charts')
+helm_repo('helm-flagger',  'https://flagger.app')
+
+# Download the standard gateway CRD set
+gateway_api = read_file(
+    download_to_cache(
+        'https://github.com/kubernetes-sigs/gateway-api/releases/download/v1.2.1/standard-install.yaml',
+        'gateway-crds.yaml'
+    )
+)
+k8s_yaml(gateway_api)
+
+# Now let let's see all the CRDs defined here and bundle them up
+crds = [res for res in decode_yaml_stream(gateway_api) if res['kind'] == 'CustomResourceDefinition']
+k8s_resource(new_name='gateway-crds', objects=[name(crd) for crd in crds], labels='gateway')
+
+local_resource(
+  'gateway-crds-ready',
+  cmd=' && '.join([('kubectl --context kind-kind wait --for=condition=Established crd %s' % name(c)) for c in crds]),
+  resource_deps=['gateway-crds'], labels='gateway')
+
+# Once the CRDs are ready, we can also load rbac
+gateway_rbac = read_file(
+    download_to_cache(
+        'https://raw.githubusercontent.com/traefik/traefik/v3.2/docs/content/reference/dynamic-configuration/kubernetes-gateway-rbac.yml',
+        'gateway-rbac.yml',
+    )
+)
+k8s_yaml(gateway_rbac)
+k8s_resource(new_name='gateway-rbac', objects=[
+    name(res) for res in decode_yaml_stream(gateway_rbac)
+], resource_deps=['gateway-crds-ready'], labels='gateway')
+
+# Use traefik as service mesh and ingress
+helm_resource('traefik', 'helm-traefik/traefik', flags=[
+    '--set=image.tag=v3.2.3',
+    '--set=providers.kubernetesGateway.enabled=true',
+    '--set=gateway.enabled=true',
+    '--set=gateway.listeners.web.namespacePolicy=null',
+], resource_deps=['gateway-rbac'], port_forwards=['8000:8000'], labels='gateway')
+
+helm_resource('flagger', 'helm-flagger/flagger', flags=[
+    '--set=prometheus.install=false',
+    '--set=meshProvider=gatewayapi:v1',
+], resource_deps=['traefik'], labels='flagger')
+
+# Now let's wait until the Canary CRD is ready
+local_resource(
+  'flagger-crds-ready',
+  cmd='kubectl --context kind-kind wait --for=condition=Established crd canaries.flagger.app',
+  resource_deps=['flagger'], labels='flagger')
+
+
+# Install local k6-loadtester
+docker_build('ghcr.io/grafana/flagger-k6-webhook:development', '.')
+k8s_yaml(secret_from_dict('k6-loadtester', inputs={
+    'KUBERNETES_CLIENT': 'in-cluster',
+    'K6_LOG_FORMAT': 'json',
+    'LOG_LEVEL': 'debug'
+}))
+yaml = helm('./charts/k6-loadtester', set=[
+    'webhook.vars.KUBERNETES_CLIENT=in-cluster',
+    'webhook.vars.K6_LOG_FORMAT=json',
+    'image.tag=development',
+    'logLevel=debug',
+])
+k8s_yaml(yaml)
+k8s_resource('chart-k6-loadtester', labels='flagger')
+
+# Now start a dev workload and let flagger create a route for it:
+if os.path.exists('dev-workload.yml'):
+    k8s_yaml('dev-workload.yml')
+    k8s_resource('my-app', new_name='workload', objects=['my-app:Canary:default'], resource_deps=['flagger-crds-ready'], labels='workload')
+

charts/k6-loadtester/templates/deployment.yaml

@@ -26,7 +26,7 @@ spec:
       securityContext:
         {{- toYaml .Values.podSecurityContext | nindent 8 }}
       volumes:
-        {{- toYaml .Values.volumes | nindent 8 }}        
+        {{- toYaml (concat .Values.volumes (list (dict "name" "tempdir" "emptyDir" (dict)))) | nindent 8 }}        
       initContainers:
 {{ toYaml .Values.initContainers | nindent 8 }} 
       containers:
@@ -54,7 +54,7 @@ spec:
                   key: {{ $k | quote }}
             {{- end }}                       
           volumeMounts:
-            {{- toYaml .Values.volumeMounts | nindent 12 }}             
+            {{- toYaml (concat .Values.volumeMounts (list (dict "mountPath" "/tmp" "name" "tempdir"))) | nindent 12 }}             
       {{- with .Values.nodeSelector }}
       nodeSelector:
         {{- toYaml . | nindent 8 }}

dev-workload.dist.yml

@@ -0,0 +1,54 @@
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: my-app
+spec:
+  selector:
+    matchLabels:
+      app: my-app
+  template:
+    metadata:
+      labels:
+        app: my-app
+    spec:
+      containers:
+        - name: main
+          image: "nginx:1.27.1-alpine"
+          ports:
+            - containerPort: 80
+---
+apiVersion: flagger.app/v1beta1
+kind: Canary
+metadata:
+  name: my-app
+spec:
+  analysis:
+    alerts: []
+    interval: 30s
+    iterations: 1
+    threshold: 2
+    webhooks:
+    - metadata:
+        notification_context: 'Cluster: `dev-cluster`'
+        script: |
+          import http from 'k6/http';
+          export default function () {
+            http.get('http://my-app-canary.default:80/');
+          }
+      name: k6-load-test
+      timeout: 5m
+      type: pre-rollout
+      url: http://chart-k6-loadtester.default:8000/launch-test
+  service:
+    name: my-app-svc
+    port: 80
+    portDiscovery: true
+    targetPort: 80
+    gatewayRefs:
+      - name: traefik-gateway
+        namespace: default
+  targetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: my-app