From 218217cdcfb190acafa8e0f4fb8ccec56b22faaf Mon Sep 17 00:00:00 2001
From: dtfranz <dfranz@redhat.com>
Date: Tue, 28 Feb 2023 10:49:24 -0800
Subject: [PATCH] Remote debug make target

Adds debug make target to rukpak. The debug target is essentially the same as the run target except that, once finished, it exposes a local port to allow for remote debugging in the rukpak core container.

Signed-off-by: dtfranz <dfranz@redhat.com>
---
 Makefile                                      | 22 ++++++++----
 README.md                                     | 29 +++++++++++++++
 test/tools/remotedebug/kind-config.yaml       |  9 +++++
 test/tools/remotedebug/kustomization.yaml     | 14 ++++++++
 .../remotedebug/patch/install_dlv_init.yaml   | 35 +++++++++++++++++++
 .../patch/remote_debug_command.yaml           | 33 +++++++++++++++++
 test/tools/remotedebug/resources/service.yaml | 14 ++++++++
 7 files changed, 150 insertions(+), 6 deletions(-)
 create mode 100644 test/tools/remotedebug/kind-config.yaml
 create mode 100644 test/tools/remotedebug/kustomization.yaml
 create mode 100644 test/tools/remotedebug/patch/install_dlv_init.yaml
 create mode 100644 test/tools/remotedebug/patch/remote_debug_command.yaml
 create mode 100644 test/tools/remotedebug/resources/service.yaml

diff --git a/Makefile b/Makefile
index f42544e9..daee0830 100644
--- a/Makefile
+++ b/Makefile
@@ -109,7 +109,7 @@ e2e: KIND_CLUSTER_NAME=rukpak-e2e
 e2e: rukpakctl run image-registry local-git kind-load-bundles registry-load-bundles test-e2e kind-cluster-cleanup ## Run e2e tests against an ephemeral kind cluster
 
 kind-cluster: kind kind-cluster-cleanup ## Standup a kind cluster
-	$(KIND) create cluster --name ${KIND_CLUSTER_NAME}
+	$(KIND) create cluster --name ${KIND_CLUSTER_NAME} ${KIND_CLUSTER_CONFIG}
 	$(KIND) export kubeconfig --name ${KIND_CLUSTER_NAME}
 
 kind-cluster-cleanup: kind ## Delete the kind cluster
@@ -124,14 +124,15 @@ local-git: ## Setup in-cluster git repository
 ###################
 # Install and Run #
 ###################
-.PHONY: install install-manifests wait run cert-mgr uninstall
+.PHONY: install install-manifests wait run debug debug-helper cert-mgr uninstall
 
 ##@ install/run:
 
 install: generate cert-mgr install-manifests wait ## Install rukpak
 
+MANIFESTS_DIR ?= manifests
 install-manifests:
-	$(KUBECTL) apply -k manifests
+	$(KUBECTL) apply -k $(MANIFESTS_DIR)
 
 wait:
 	$(KUBECTL) wait --for=condition=Available --namespace=$(RUKPAK_NAMESPACE) deployment/core --timeout=60s
@@ -141,12 +142,21 @@ wait:
 
 run: build-container kind-cluster kind-load install ## Build image, stop/start a local kind cluster, and run operator in that cluster
 
+debug: MANIFESTS_DIR = test/tools/remotedebug ## Same as 'run' target with the addition of remote debugging available on port 40000
+debug: DEBUG_FLAGS = -gcflags="all=-N -l"
+debug: KIND_CLUSTER_CONFIG = --config=./test/tools/remotedebug/kind-config.yaml
+debug: run debug-helper
+
+debug-helper:
+	@echo ''
+	@echo "Remote Debugging for '$$($(KUBECTL) -n $(RUKPAK_NAMESPACE) get pods -l app=core -o name)' in namespace '$(RUKPAK_NAMESPACE)' now available through localhost:40000"
+
 cert-mgr: ## Install the certification manager
 	$(KUBECTL) apply -f https://github.com/cert-manager/cert-manager/releases/download/$(CERT_MGR_VERSION)/cert-manager.yaml
 	$(KUBECTL) wait --for=condition=Available --namespace=cert-manager deployment/cert-manager-webhook --timeout=60s
 
 uninstall: ## Remove all rukpak resources from the cluster
-	$(KUBECTL) delete -k manifests
+	$(KUBECTL) delete -k $(MANIFESTS_DIR)
 
 ##################
 # Build and Load #
@@ -165,10 +175,10 @@ VERSION_FLAGS=-ldflags "-X $(VERSION_PATH).GitCommit=$(GIT_COMMIT)"
 build: $(BINARIES)
 
 $(LINUX_BINARIES):
-	CGO_ENABLED=0 GOOS=linux go build -tags $(GO_BUILD_TAGS) $(VERSION_FLAGS) -o $(BIN_DIR)/$@ ./cmd/$(notdir $@)
+	CGO_ENABLED=0 GOOS=linux go build $(DEBUG_FLAGS) -tags $(GO_BUILD_TAGS) $(VERSION_FLAGS) -o $(BIN_DIR)/$@ ./cmd/$(notdir $@) 
 
 $(BINARIES):
-	CGO_ENABLED=0 go build -tags $(GO_BUILD_TAGS) $(VERSION_FLAGS) -o $(BIN_DIR)/$@ ./cmd/$@
+	CGO_ENABLED=0 go build $(DEBUG_FLAGS) -tags $(GO_BUILD_TAGS) $(VERSION_FLAGS) -o $(BIN_DIR)/$@ ./cmd/$@ $(DEBUG_FLAGS)
 
 build-container: $(LINUX_BINARIES) ## Builds provisioner container image locally
 	$(CONTAINER_RUNTIME) build -f Dockerfile -t $(IMAGE) $(BIN_DIR)/linux
diff --git a/README.md b/README.md
index a2a29165..693cfe1c 100644
--- a/README.md
+++ b/README.md
@@ -63,6 +63,35 @@ make run
 
 > Note: RukPak may take some time to become fully operational while its controllers and webhooks are spinning up during installation. As a result, please allow a few moments before creating Bundles/BundleDeployments if you are noticing unexpected failures.
 
+### Debugging
+
+The following make target is also available to developers that wish to debug the container remotely through `dlv`. Once completed, a remote debugging session may be attached through any preferred IDE on `localhost:40000` :
+
+```bash
+make debug
+```
+
+As an example, the following `launch.json` file may be used to connect to the debugging session with vscode:
+```json
+{
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "name": "Remote Debugging",
+      "type": "go",
+      "request": "attach",
+      "mode": "remote",
+      "remotePath": "",
+      "port":40000,
+      "host":"127.0.0.1",
+      "showLog": true,
+      "trace": "log",
+      "logOutput": "rpc"
+    }
+  ]
+}
+```
+
 There are currently no other supported ways of installing RukPak, although there are plans to add support for other
 popular packaging formats such as a Helm chart or an OLM bundle.
 
diff --git a/test/tools/remotedebug/kind-config.yaml b/test/tools/remotedebug/kind-config.yaml
new file mode 100644
index 00000000..e8bfb379
--- /dev/null
+++ b/test/tools/remotedebug/kind-config.yaml
@@ -0,0 +1,9 @@
+apiVersion: kind.x-k8s.io/v1alpha4
+kind: Cluster
+nodes:
+- role: control-plane
+  extraPortMappings:
+  - containerPort: 31111
+    hostPort: 40000
+    listenAddress: "0.0.0.0" # Optional, defaults to "0.0.0.0"
+    protocol: tcp # Optional, defaults to tcp
diff --git a/test/tools/remotedebug/kustomization.yaml b/test/tools/remotedebug/kustomization.yaml
new file mode 100644
index 00000000..935d2003
--- /dev/null
+++ b/test/tools/remotedebug/kustomization.yaml
@@ -0,0 +1,14 @@
+resources:
+  - ../../../manifests/
+  - ./resources/service.yaml
+
+patchesJson6902:
+- target:
+    group: apps
+    version: v1
+    kind: Deployment
+    name: core
+  path: patch/remote_debug_command.yaml
+
+patchesStrategicMerge:
+  - patch/install_dlv_init.yaml
diff --git a/test/tools/remotedebug/patch/install_dlv_init.yaml b/test/tools/remotedebug/patch/install_dlv_init.yaml
new file mode 100644
index 00000000..aeeaa361
--- /dev/null
+++ b/test/tools/remotedebug/patch/install_dlv_init.yaml
@@ -0,0 +1,35 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  namespace: rukpak-system
+  name: core
+spec:
+  template:
+    spec:
+      securityContext:
+        runAsNonRoot: false
+      volumes:
+      - name: gobindir
+        emptyDir: {}
+      initContainers:
+        - name: install-dlv
+          env:
+          - name: CGO_ENABLED
+            value: "0"
+          image: golang:1.17
+          command:
+          - go
+          args:
+          - install
+          - -ldflags
+          - "-s -w -extldflags '-static'"
+          - github.com/go-delve/delve/cmd/dlv@latest
+          volumeMounts:
+          - name: gobindir
+            mountPath: /go/bin/
+      containers:
+        - name: kube-rbac-proxy
+        - name: manager
+          volumeMounts:
+          - name: gobindir
+            mountPath: /go/bin/
diff --git a/test/tools/remotedebug/patch/remote_debug_command.yaml b/test/tools/remotedebug/patch/remote_debug_command.yaml
new file mode 100644
index 00000000..e4c096cd
--- /dev/null
+++ b/test/tools/remotedebug/patch/remote_debug_command.yaml
@@ -0,0 +1,33 @@
+# Move the original command to the beginning of the args array
+- op: copy
+  from: /spec/template/spec/containers/1/command/0
+  path: /spec/template/spec/containers/1/args/0
+# Set the command to /dlv
+- op: add
+  path: /spec/template/spec/containers/1/command
+  value: ["/go/bin/dlv"]
+# Prepend the args array with the following dlv args
+- op: add
+  path: /spec/template/spec/containers/1/args/0
+  value: "--listen=:40000"
+- op: add
+  path: /spec/template/spec/containers/1/args/1
+  value: "--continue"
+- op: add
+  path: /spec/template/spec/containers/1/args/2
+  value: "--headless=true"
+- op: add
+  path: /spec/template/spec/containers/1/args/3
+  value: "--api-version=2"
+- op: add
+  path: /spec/template/spec/containers/1/args/4
+  value: "--accept-multiclient"
+- op: add
+  path: /spec/template/spec/containers/1/args/5
+  value: "--log"
+- op: add
+  path: /spec/template/spec/containers/1/args/6
+  value: "exec"
+- op: add
+  path: /spec/template/spec/containers/1/args/7
+  value: "--"
diff --git a/test/tools/remotedebug/resources/service.yaml b/test/tools/remotedebug/resources/service.yaml
new file mode 100644
index 00000000..8f44f441
--- /dev/null
+++ b/test/tools/remotedebug/resources/service.yaml
@@ -0,0 +1,14 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: core-remote-debug
+  namespace: rukpak-system
+spec:
+  type: NodePort
+  ports:
+  - port: 40000
+    targetPort: 40000
+    nodePort: 31111
+    protocol: TCP
+  selector:
+    app: core
\ No newline at end of file