SANDBOX-1561 | feature: enable debug builds for the service

build/Dockerfile.debug

@@ -0,0 +1,51 @@
+# Compile Delve in an intermediate step.
+FROM registry.access.redhat.com/ubi8/ubi:latest AS delve-builder
+
+# The Golang version must be provided as a build arguments, which will ensure
+# that Delve gets built with the same version the service's binary gets built
+# with, to avoid any discrepancies.
+ARG GOLANG_VERSION
+
+# Install Tar to be able to extract Golang.
+RUN yum install --assumeyes \
+    tar \
+    && yum clean all
+
+# Download and extract Golang.
+RUN curl --location --output ${GOLANG_VERSION}.linux-amd64.tar.gz https://go.dev/dl/${GOLANG_VERSION}.linux-amd64.tar.gz \
+    && tar --directory /usr/local --extract --file ${GOLANG_VERSION}.linux-amd64.tar.gz \
+    && rm --force ${GOLANG_VERSION}.linux-amd64.tar.gz
+
+# Put Golang in the path so that we can Delve with it.
+ENV PATH=$PATH:/usr/local/go/bin
+
+# Build Delve and leave it in a temporary directory.
+RUN GOBIN=/tmp/bin go install github.com/go-delve/delve/cmd/dlv@latest
+
+# Build the final image.
+FROM registry.access.redhat.com/ubi8/ubi-minimal:latest
+
+LABEL maintainer = "KubeSaw <devsandbox@redhat.com>"
+LABEL author = "KubeSaw <devsandbox@redhat.com>"
+
+ENV REG_SERVICE=/usr/local/bin/registration-service \
+    USER_UID=1001 \
+    USER_NAME=registration-service \
+    LANG=en_US.utf8
+
+COPY build/bin /usr/local/bin
+RUN  /usr/local/bin/user_setup
+
+# Install registration-service binary
+COPY build/_output/bin/registration-service ${REG_SERVICE}
+
+# Copy Delve to the image so that we can execute the operator with it.
+COPY --from=delve-builder /tmp/bin/dlv /usr/local/bin/dlv
+
+# Execute the service with the "dlv" command to enable debugging.
+ENTRYPOINT ["dlv", "--listen=:50000", "--headless", "--continue", "--api-version=2", "--accept-multiclient", "exec", "/usr/local/bin/registration-service"]
+
+# Expose the debugger's port along with the service's regular ports.
+EXPOSE 50000 8080 8081 8082
+
+USER ${USER_UID}

make/go.mk

@@ -11,12 +11,13 @@ goarch ?= $(shell go env GOARCH)
 # builds the production binary
 build: build-prod
 
-# buils a development binary that has no bundled assets but reads them
-# from the filesystem. Use only for development.
-## builds development binary
+# Builds a development binary that has no bundled assets but reads them from
+# the filesystem. It also builds the binary without any optimizations or
+# code inlining, so that Delve can be used to execute it. Use only for
+# development.
 build-dev:
 	$(Q)CGO_ENABLED=0 GOARCH=${goarch} GOOS=linux \
-		go build ${V_FLAG} -ldflags="${LDFLAGS}" \
+		go build -gcflags "all=-N -l" ${V_FLAG} -ldflags="${LDFLAGS}" \
 		-tags dev \
 		-o $(OUT_DIR)/bin/registration-service \
 		cmd/main.go
@@ -38,13 +39,13 @@ vendor:
 verify-dependencies: tidy vet build test lint-go-code
 
 .PHONY: tidy
-tidy: 
+tidy:
 	go mod tidy
 
 .PHONY: vet
 vet:
 	go vet ./...
-	
+
 .PHONY: pre-verify
 pre-verify:
-	echo "No Pre-requisite needed"
+	echo "No Pre-requisite needed"

make/podman.mk

@@ -10,11 +10,21 @@ IMAGE_PLATFORM ?= linux/amd64
 podman-image: build
 	$(Q)podman build --platform ${IMAGE_PLATFORM} -f build/Dockerfile -t ${IMAGE} .
 
+## Build the operator's image with Delve on it so that it is ready to attach a
+## debugger to it.
+podman-image-debug: build-dev
+	$(Q)podman build --platform ${IMAGE_PLATFORM} --build-arg GOLANG_VERSION="$$(go version | awk '{print $$3}')" --file build/Dockerfile.debug --tag ${IMAGE} .
+
 .PHONY: podman-push
 ## Push the binary image to quay.io registry
 podman-push: check-namespace podman-image
 	$(Q)podman push ${IMAGE}
 
+.PHONY: podman-push-debug
+## Push the image with the debugger in it to the repository.
+podman-push-debug: check-namespace podman-image-debug
+	$(Q)podman push ${IMAGE}
+
 .PHONY: check-namespace
 check-namespace:
 ifeq ($(QUAY_NAMESPACE),${GO_PACKAGE_ORG_NAME})

scripts/deploy-dev.sh

@@ -32,16 +32,36 @@ setup() {
 }
 
 refresh() {
+    # Create a flag for when we need to build the "debug" images instead.
+    if [[ "$1" == "debug" ]]
+    then
+      DEBUG=true
+    else
+      DEBUG=false
+    fi
+
     # build the registration service
     echo "📦 building the binary"
-    VERBOSE=0 make build
+    if [[ "${DEBUG}" = true ]]
+    then
+      VERBOSE=0 make build-dev
+    else
+      VERBOSE=0 make build
+    fi
     echo "✅ done"
 
     echo "📦 building the image"
     REGISTRY_ROUTE=$(oc get route default-route -n openshift-image-registry --template='{{ .spec.host }}')
     TIMESTAMP=$(date +%s)
     IMAGE_NAME=registration-service:dev-$TIMESTAMP
-    podman build -f build/Dockerfile -t $REGISTRY_ROUTE/$HOST_NS/$IMAGE_NAME .
+
+    # Build the debug image with podman.
+    if [[ "${DEBUG}" = true ]]
+    then
+      IMAGE="${REGISTRY_ROUTE}/${HOST_NS}/${IMAGE_NAME}" VERBOSE=0 make podman-image-debug
+    else
+      IMAGE="${REGISTRY_ROUTE}/${HOST_NS}/${IMAGE_NAME}" VERBOSE=0 make podman-image
+    fi
     echo "✅ done"
 
     # copy/replace the binary into the pod's container
@@ -51,17 +71,23 @@ refresh() {
 
     # restart the process in the pod's container
     INTERNAL_REGISTRY=image-registry.openshift-image-registry.svc:5000
-    echo "✏️ patching the deployment with image $INTERNAL_REGISTRY/$HOST_NS/$IMAGE_NAME"
-    oc patch deployment/registration-service -n $HOST_NS --type='json' -p="[{\"op\": \"replace\", \"path\": \"/spec/template/spec/containers/0/image\", \"value\":\"$INTERNAL_REGISTRY/$HOST_NS/$IMAGE_NAME\"}]"
+    echo "✏️ patching the deployment with the pushed image ${INTERNAL_REGISTRY}/${HOST_NS}/${IMAGE_NAME}"
+    oc patch deployment/registration-service -n ${HOST_NS} --type='json' -p='[{"op": "replace", "path": "/spec/template/spec/containers/0/image", "value":"'"${INTERNAL_REGISTRY}/${HOST_NS}/${IMAGE_NAME}"'"}]'
+
+    if [[ "${DEBUG}" = true ]]
+    then
+      echo "✏️ patching the deployment's command to execute the registration service with Delve instead"
+      oc patch deployment/registration-service --namespace "${HOST_NS}" --type='json' --patch='[{"op": "replace", "path": "/spec/template/spec/containers/0/command", "value": ["dlv", "--listen=:50000", "--headless", "--continue", "--api-version=2", "--accept-multiclient", "exec", "/usr/local/bin/registration-service"]}'
+    fi
     # oc rollout restart deployment/registration-service
 
     # Et voilà!
     echo "👋 all done!"
 }
 
-if [ -z "$HOST_NS" ]; then 
-    echo "HOST_NS is not set"; 
-    exit 1; 
+if [ -z "$HOST_NS" ]; then
+    echo "HOST_NS is not set";
+    exit 1;
 fi
 
 if declare -f "$1" > /dev/null
@@ -72,8 +98,9 @@ else
     # Show a helpful error
     echo "'$1' is not a valid command" >&2
     echo "available commands:"
-    echo "setup     Configure the deployment with a single pod"
-    echo "refresh   Rebuild the registration-service and update the pod"
+    echo "setup         Configure the deployment with a single pod"
+    echo "refresh       Rebuild the registration-service and update the pod"
+    echo "refresh debug Rebuild the registration service with Delve on it listening on port 50000"
     echo ""
     exit 1
 fi