docs: describe local debug via delve

DEVELOPMENT.md

@@ -5,6 +5,7 @@
 <!-- toc -->
 - [Prerequisites](#prerequisites)
 - [Getting Started](#getting-started)
+  - [🐛 Debugging](#-debugging)
 <!-- /toc -->
 
 ## Prerequisites
@@ -27,3 +28,41 @@ All other remaining tools (e.g. `kustomize`) are getting installed automatically
 
    The `make tilt-up` command will give you the URL to the local tilt environment.
 1. Time to start developing. 🎉
+
+
+### 🐛 Debugging
+
+To improve the local development process, we add [delve](https://github.com/go-delve/delve) into `garm-operator` container image.
+This allows us to debug the `garm-operator` running in the local `kind` cluster.
+
+The following steps are required to start debugging the `garm-operator`:
+
+1. set the `mode` variable from `local` to `debug` in the `Tiltfile`
+
+   This will start the `garm-operator` container with the `command` and `args` specified in the [`config/overlays/debug/manager_patch.yaml`](config/overlays/debug/manager_patch.yaml) file. (Ensure that the correct GARM credentials are set.)
+
+   The `garm-operator-controller-manager` pod should log then print the following log message which indicates that you are able to attach a debugger to the `garm-operator`:
+
+   ```
+   2023-12-08T15:39:21Z warning layer=rpc Listening for remote connections (connections are not authenticated nor encrypted)
+   API server listening at: [::]:2345
+   ```
+
+1. IDE configuration
+   1. VSCode
+      1. Create a `launch.json` file in the `.vscode` directory with the following content:
+         ```json
+         {
+             "version": "0.2.0",
+             "configurations": [
+                 {
+                     "name": "garm-operator - attach",
+                     "type": "go",
+                     "request": "attach",
+                     "mode": "remote",
+                     "port": 2345
+                 }
+             ]
+         }
+         ```
+1. Happy debugging 🐛

Dockerfile

@@ -18,18 +18,23 @@ COPY api/ api/
 COPY internal/controller/ internal/controller/
 COPY pkg/ pkg/
 
+# install delve(dlv) for debugging
+RUN go install github.com/go-delve/delve/cmd/dlv@latest
+
 # Build
 # the GOARCH has not a default value to allow the binary be built according to the host where the command
 # was called. For example, if we call make docker-build in a local env which has the Apple Silicon M1 SO
 # the docker BUILDPLATFORM arg will be linux/arm64 when for Apple x86 it will be linux/amd64. Therefore,
 # by leaving it empty we can ensure that the container and binary shipped on it will have the same platform.
-RUN --mount=type=cache,target=/root/.cache/go-build CGO_ENABLED=0 GOOS=${TARGETOS:-linux} GOARCH=${TARGETARCH} go build -o manager cmd/main.go
+RUN --mount=type=cache,target=/root/.cache/go-build CGO_ENABLED=0 GOOS=${TARGETOS:-linux} GOARCH=${TARGETARCH} go build -gcflags "-N -l" -o manager cmd/main.go
 
 # Use distroless as minimal base image to package the manager binary
 # Refer to https://github.com/GoogleContainerTools/distroless for more details
-FROM gcr.io/distroless/static:nonroot
+FROM busybox:stable
 WORKDIR /
 COPY --from=builder /workspace/manager .
+COPY --from=builder /go/bin/dlv .
+
 USER 65532:65532
 
 ENTRYPOINT ["/manager"]

Tiltfile

@@ -13,7 +13,15 @@ deploy_cert_manager(
     version='v1.12.0' # the version of cert-manager to deploy
 )
 
-templated_yaml = kustomize('config/overlays/local')
+# mode could be either 'local' or 'debug'
+# when set to 'debug', delve will be used within the container to start
+# the manager binary and the dlv debug port will be exposed
+#
+# for more details, please read the DEVELOPMENT.md
+mode = 'local' 
+
+# kustomize overlays
+templated_yaml = kustomize('config/overlays/' + mode)
 k8s_yaml(templated_yaml)
 
 # for not having uncategorized resources in the tilt ui
@@ -39,6 +47,9 @@ k8s_resource(
         'garm-operator-validating-webhook-configuration:validatingwebhookconfiguration',
         ],
     labels=["operator"],
+    port_forwards=[2345], # dlv debug port
 )
 
-docker_build('localhost:5000/controller', '.')
+docker_build('localhost:5000/controller', '.', 
+    ignore=['.github', 'config', 'docs', 'hack', '*.md']
+)

config/manager/manager.yaml

@@ -44,44 +44,44 @@ spec:
       securityContext:
         runAsNonRoot: true
       containers:
-      - command:
-        - /manager
-        args:
-        - --garm-server=$GARM_SERVER_URL
-        - --garm-username=$GARM_SERVER_USERNAME
-        - --garm-password=$GARM_SERVER_PASSWORD
-        - --operator-watch-namespace=$OPERATOR_WATCH_NAMESPACE
-        image: controller:latest
-        name: manager
-        securityContext:
-          allowPrivilegeEscalation: false
-          capabilities:
-            drop:
-              - "ALL"
-        livenessProbe:
-          httpGet:
-            path: /healthz
-            port: 8081
-          initialDelaySeconds: 15
-          periodSeconds: 20
-        readinessProbe:
-          httpGet:
-            path: /readyz
-            port: 8081
-          initialDelaySeconds: 5
-          periodSeconds: 10
-        # TODO(user): Configure the resources accordingly based on the project requirements.
-        # More info: https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/
-        resources:
-          limits:
-            cpu: 500m
-            memory: 128Mi
-          requests:
-            cpu: 10m
-            memory: 64Mi
-        volumeMounts:
-          - name: serviceaccount-volume
-            mountPath: /var/run/secrets/kubernetes.io/serviceaccount
+        - command:
+            - /manager
+          args:
+            - --garm-server=$GARM_SERVER_URL
+            - --garm-username=$GARM_SERVER_USERNAME
+            - --garm-password=$GARM_SERVER_PASSWORD
+            - --operator-watch-namespace=$OPERATOR_WATCH_NAMESPACE
+          image: controller:latest
+          name: manager
+          securityContext:
+            allowPrivilegeEscalation: false
+            capabilities:
+              drop:
+                - "ALL"
+          livenessProbe:
+            httpGet:
+              path: /healthz
+              port: 8081
+            initialDelaySeconds: 15
+            periodSeconds: 20
+          readinessProbe:
+            httpGet:
+              path: /readyz
+              port: 8081
+            initialDelaySeconds: 5
+            periodSeconds: 10
+          # TODO(user): Configure the resources accordingly based on the project requirements.
+          # More info: https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/
+          resources:
+            limits:
+              cpu: 500m
+              memory: 128Mi
+            requests:
+              cpu: 10m
+              memory: 64Mi
+          volumeMounts:
+            - name: serviceaccount-volume
+              mountPath: /var/run/secrets/kubernetes.io/serviceaccount
       volumes:
         # use a custom token with specified expiration time - this implementation behaves like the default token mechanism
         # see: https://kubernetes.io/docs/reference/access-authn-authz/service-accounts-admin/#bound-service-account-token-volume

config/overlays/debug/kustomization.yaml

@@ -0,0 +1,11 @@
+resources:
+  - ../../default
+
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+images:
+  - name: controller
+    newName: localhost:5000/controller
+
+patches:
+  - path: manager_patch.yaml

config/overlays/debug/manager_patch.yaml

@@ -0,0 +1,37 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: garm-operator-controller-manager
+  namespace: garm-operator-system
+spec:
+  template:
+    spec:
+      containers:
+        - name: manager
+          command:
+            [
+              "/dlv",
+              "--listen=:2345",
+              "--headless=true",
+              "--api-version=2",
+              "--accept-multiclient",
+              "exec",
+              "/manager",
+              "--wd",
+              "/tmp",
+              "--",
+            ]
+          args:
+            - --garm-server=http://garm-server.garm-server.svc:9997
+            - --garm-username=admin
+            - --garm-password=LmrBG1KcBOsDfNKq4cQTGpc0hJ0kejkk
+            - --operator-watch-namespace=garm-operator-system
+          ports:
+            - containerPort: 2345
+              name: delve
+              protocol: TCP
+          resources:
+            limits:
+              memory: 1Gi
+            requests:
+              memory: 1Gi

config/overlays/local/manager_patch.yaml

@@ -13,4 +13,3 @@ spec:
             - --garm-username=admin
             - --garm-password=LmrBG1KcBOsDfNKq4cQTGpc0hJ0kejkk
             - --operator-watch-namespace=garm-operator-system
-