From 83e14f4dcde82eda7dafc497107349a628dc90f1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20Sch=C3=BCller?= <florian.schueller@redhat.com>
Date: Thu, 11 Apr 2024 18:18:30 +0200
Subject: [PATCH] Makefile: support for golang debugging

---
 Makefile                                  | 10 ++++---
 containers/osbuild-composer/entrypoint.py | 33 +++++++++++++++++++++--
 distribution/Dockerfile-composer          |  5 ++--
 distribution/Dockerfile-worker_srcinstall |  3 ++-
 4 files changed, 43 insertions(+), 8 deletions(-)

diff --git a/Makefile b/Makefile
index 40e67bac96e..ca3d747f703 100644
--- a/Makefile
+++ b/Makefile
@@ -317,6 +317,10 @@ WORKER_SRC_DEPS := $(SRC_DEPS)
 COMPOSER_SRC_DEPS := $(SRC_DEPS)
 
 GOMODARGS ?= -modfile=go.local.mod
+# gcflags "-N -l" for golang to allow debugging
+GCFLAGS ?= -gcflags=all=-N -gcflags=all=-l
+
+CONTAINER_DEPS_COMPOSER := ./containers/osbuild-composer/entrypoint.py
 
 USE_BTRFS ?= yes
 
@@ -331,12 +335,12 @@ go.local.mod go.local.sum: $(SRC_DEPS_EXTERNAL_DIRS) go.mod $(SRC_DEPS_EXTERNAL)
 	env GOPROXY=$(GOPROXY) go mod vendor $(GOMODARGS)
 
 container_worker_built.info: go.local.mod $(WORKER_SRC_DEPS) $(DOCKERFILE_WORKER)
-	$(CONTAINER_EXECUTABLE) build -t $(DOCKER_IMAGE_WORKER) -f $(DOCKERFILE_WORKER) --build-arg GOMODARGS=$(GOMODARGS) --build-arg USE_BTRFS=$(USE_BTRFS) .
+	$(CONTAINER_EXECUTABLE) build -t $(DOCKER_IMAGE_WORKER) -f $(DOCKERFILE_WORKER) --build-arg GOMODARGS="$(GOMODARGS)"  --build-arg GCFLAGS="$(GCFLAGS)" --build-arg USE_BTRFS=$(USE_BTRFS) .
 	echo "Worker last built on" > $@
 	date >> $@
 
-container_composer_built.info: go.local.mod $(COMPOSER_SRC_DEPS) $(DOCKERFILE_COMPOSER)
-	$(CONTAINER_EXECUTABLE) build -t $(DOCKER_IMAGE_COMPOSER) -f $(DOCKERFILE_COMPOSER) --build-arg GOMODARGS=$(GOMODARGS) .
+container_composer_built.info: go.local.mod $(COMPOSER_SRC_DEPS) $(DOCKERFILE_COMPOSER) $(CONTAINER_DEPS_COMPOSER)
+	$(CONTAINER_EXECUTABLE) build -t $(DOCKER_IMAGE_COMPOSER) -f $(DOCKERFILE_COMPOSER) --build-arg GOMODARGS="$(GOMODARGS)" --build-arg GCFLAGS="$(GCFLAGS)" .
 	echo "Composer last built on" > $@
 	date >> $@
 
diff --git a/containers/osbuild-composer/entrypoint.py b/containers/osbuild-composer/entrypoint.py
index 8fc0b093b73..21ff06a4366 100644
--- a/containers/osbuild-composer/entrypoint.py
+++ b/containers/osbuild-composer/entrypoint.py
@@ -333,12 +333,37 @@ def handler(signum, frame):
         liveness.touch()
 
         try:
-            if self.args.builtin_worker:
+            should_launch_composer = any([self.args.weldr_api, self.args.composer_api, self.args.local_worker_api, self.args.remote_worker_api])
+            if self.args.builtin_worker or not should_launch_composer:
+                if not should_launch_composer:
+                    print(f"NOTE: launching worker only - no API for composer enabled")
                 proc_worker = self._spawn_worker()
 
-            if any([self.args.weldr_api, self.args.composer_api, self.args.local_worker_api, self.args.remote_worker_api]):
+            if should_launch_composer:
                 proc_composer = self._spawn_composer(sockets)
 
+            debug_port = os.environ.get('GODEBUG_PORT')
+            debugger = None
+
+            if debug_port:
+                # only debug one - either composer or worker if there is no composer
+                child_pid = proc_composer.pid if proc_composer else proc_worker.pid
+                debug_target_name = "image-builder-composer" if proc_composer else "image-builder-worker"
+
+                debugger_cmd = [
+                    "/usr/bin/dlv",
+                    "attach",
+                    "--headless=true",
+                    "--api-version", "2",
+                    "--listen", f":{debug_port}",
+                    str(child_pid),
+                    "/usr/libexec/osbuild-composer/osbuild-composer"
+                ]
+
+                print(f"NOTE: you HAVE to attach the debugger NOW otherwise { debug_target_name } "
+                      f"will not continue running")
+                debugger = subprocess.Popen(debugger_cmd)
+
             if proc_composer:
                 res = proc_composer.wait()
 
@@ -347,6 +372,10 @@ def handler(signum, frame):
                     proc_worker.terminate()
                 proc_worker.wait()
 
+            if debugger:
+                debugger.wait()
+
+
         except KeyboardInterrupt:
             if proc_composer:
                 proc_composer.terminate()
diff --git a/distribution/Dockerfile-composer b/distribution/Dockerfile-composer
index 7975a5327a0..819999b41f8 100644
--- a/distribution/Dockerfile-composer
+++ b/distribution/Dockerfile-composer
@@ -11,15 +11,16 @@ ARG GOPROXY=https://proxy.golang.org,direct
 RUN go env -w GOPROXY=$GOPROXY
 
 ARG GOMODARGS=""
+ARG GCFLAGS=""
 
-RUN go install $GOMODARGS ./cmd/osbuild-composer/
+RUN go install $GOMODARGS $GCFLAGS ./cmd/osbuild-composer/
 
 FROM registry.access.redhat.com/ubi9/go-toolset:latest AS builder2
 RUN go install github.com/jackc/tern@latest
 
 FROM fedora:39
 
-RUN dnf install -y python3 python3-dnf gpgme libassuan device-mapper-libs
+RUN dnf install -y python3 python3-dnf gpgme libassuan device-mapper-libs delve
 RUN mkdir -p "/usr/libexec/osbuild-composer"
 RUN mkdir -p "/etc/osbuild-composer/"
 RUN mkdir -p "/run/osbuild-composer/"
diff --git a/distribution/Dockerfile-worker_srcinstall b/distribution/Dockerfile-worker_srcinstall
index 6eb78d4ffe2..613f0b63c48 100644
--- a/distribution/Dockerfile-worker_srcinstall
+++ b/distribution/Dockerfile-worker_srcinstall
@@ -18,8 +18,9 @@ ARG GOPROXY=https://proxy.golang.org,direct
 RUN go env -w GOPROXY=$GOPROXY
 
 ARG GOMODARGS=""
+ARG GCFLAGS=""
 
-RUN go install $GOMODARGS ./cmd/osbuild-worker
+RUN go install $GOMODARGS $GCFLAGS ./cmd/osbuild-worker
 
 FROM osbuild_devel