Adding a hack/debug script

Makefile

@@ -1,29 +1,8 @@
 # Root directory of the project (absolute path).
 ROOTDIR=$(dir $(abspath $(lastword $(MAKEFILE_LIST))))
 
-# Base path used to install.
-DESTDIR=/usr/local
-
-# Used to populate version variable in main package.
-VERSION=$(shell git describe --match 'v[0-9]*' --dirty='.m' --always)
-
 PROJECT_ROOT=github.com/docker/swarmkit
 
-# Race detector is only supported on amd64.
-RACE := $(shell test $$(go env GOARCH) != "amd64" || (echo "-race"))
-
-# Project packages.
-PACKAGES=$(shell go list ./... | grep -v /vendor/)
-INTEGRATION_PACKAGE=${PROJECT_ROOT}/integration
-
-# Project binaries.
-COMMANDS=swarmd swarmctl swarm-bench swarm-rafttool protoc-gen-gogoswarm
-BINARIES=$(addprefix bin/,$(COMMANDS))
-
-VNDR=$(shell which vndr || echo '')
-
-GO_LDFLAGS=-ldflags "-X `go list ./version`.Version=$(VERSION)"
-
 SHELL := /bin/bash
 
 # stop here. do we want to run everything inside of a container, or do we want

containerized.mk

@@ -2,6 +2,8 @@ IMAGE_NAME=docker/swarmkit
 GOPATH=/go
 DOCKER_IMAGE_DIR=${GOPATH}/src/${PROJECT_ROOT}
 
+DOCKER_SWARMKIT_DELVE_PORT ?= 2345
+
 # don't bother writing every single make target. just pass the call through to
 # docker and make
 # we prefer `%:` to `.DEFAULT` as the latter doesn't run phony deps
@@ -40,10 +42,16 @@ run: ensure_image_exists
 	@ [ "$$DOCKER_SWARMKIT_DOCKER_RUN_CMD" ] || exit 1
 	@ DOCKER_RUN_COMMAND="docker run -t -v swarmkit-cache:${GOPATH}" \
 		&& if [ "$$DOCKER_SWARMKIT_USE_DOCKER_SYNC" ]; then \
-			$(MAKE) ensure_sync_started && DOCKER_RUN_COMMAND="$$DOCKER_RUN_COMMAND -v swarmkit-sync:${DOCKER_IMAGE_DIR}"; \
+			$(MAKE) ensure_sync_started && DOCKER_RUN_COMMAND+=" -v swarmkit-sync:${DOCKER_IMAGE_DIR}"; \
 		else \
-			DOCKER_RUN_COMMAND="$$DOCKER_RUN_COMMAND -v ${ROOTDIR}:${DOCKER_IMAGE_DIR}"; \
+			DOCKER_RUN_COMMAND+=" -v ${ROOTDIR}:${DOCKER_IMAGE_DIR}"; \
+		fi \
+		&& if [ "$$DOCKER_SWARMKIT_USE_DELVE" ]; then \
+			DOCKER_RUN_COMMAND="DOCKER_SWARMKIT_DELVE_PORT=${DOCKER_SWARMKIT_DELVE_PORT} $$DOCKER_RUN_COMMAND" ; \
+			DOCKER_RUN_COMMAND+=" -p ${DOCKER_SWARMKIT_DELVE_PORT}:${DOCKER_SWARMKIT_DELVE_PORT} -e DOCKER_SWARMKIT_DELVE_PORT"; \
+			`# see https://github.com/derekparker/delve/issues/515#issuecomment-214911481'` ; \
+			DOCKER_RUN_COMMAND+=" --security-opt=seccomp:unconfined"; \
 		fi \
-		&& DOCKER_RUN_COMMAND="$$DOCKER_RUN_COMMAND $$DOCKER_SWARMKIT_DOCKER_RUN_FLAGS ${IMAGE_NAME} $$DOCKER_SWARMKIT_DOCKER_RUN_CMD" \
+		&& DOCKER_RUN_COMMAND+=" $$DOCKER_SWARMKIT_DOCKER_RUN_FLAGS ${IMAGE_NAME} $$DOCKER_SWARMKIT_DOCKER_RUN_CMD" \
 		&& echo $$DOCKER_RUN_COMMAND \
-		&& $$DOCKER_RUN_COMMAND
+		&& eval $$DOCKER_RUN_COMMAND

direct.mk

@@ -1,3 +1,25 @@
+# Base path used to install.
+DESTDIR=/usr/local
+
+# Used to populate version variable in main package.
+VERSION=$(shell git describe --match 'v[0-9]*' --dirty='.m' --always)
+
+# Race detector is only supported on amd64.
+RACE := $(shell test $$(go env GOARCH) != "amd64" || (echo "-race"))
+
+# Project packages.
+PACKAGES=$(shell go list ./... | grep -v /vendor/)
+INTEGRATION_PACKAGE=${PROJECT_ROOT}/integration
+
+# Project binaries.
+COMMANDS=swarmd swarmctl swarm-bench swarm-rafttool protoc-gen-gogoswarm
+BINARIES=$(addprefix bin/,$(COMMANDS))
+
+VNDR=$(shell which vndr || echo '')
+
+GO_LDFLAGS=-ldflags "-X `go list ./version`.Version=$(VERSION)"
+
+
 .DEFAULT_GOAL = all
 .PHONY: all
 all: check binaries test integration-tests ## run check, build the binaries and run the tests

hack/debug

@@ -0,0 +1,71 @@
+#!/bin/bash
+
+## Installs delve, then runs it as a headless server
+## Keeps running until killed
+## Also adds some goodies: delve servers ignore interrupts, which is annoying...
+## and also once a debugging session is done, the server just hangs there, which
+## is equally annoying.
+## This script takes care of both these things
+
+SUBSHELL_PID=
+DLV_PID_FILE=
+RUNNING=true
+
+main() {
+  [ "$1" ] || usage
+
+  ensure_delve_installed || exit $?
+
+  local PORT="$DOCKER_SWARMKIT_DELVE_PORT"
+  [ "$PORT" ] || PORT=2345
+
+  local DLV_CMD="dlv test --accept-multiclient --headless --listen=:$PORT --api-version=2 --log $@"
+  echo $DLV_CMD
+
+  trap handle_interrupt INT
+
+  DLV_PID_FILE=$(mktemp /tmp/dlv.XXXXXX.pid)
+  local DLV_OUTPUT_FILE=$(mktemp /tmp/dlv.XXXXXX.out)
+
+  # the weird regex is because we keep the output colored
+  local HALTING_REGEX='^\e\[37mDEBU\e\[0m\[[0-9]+\] halting\s+\e\[37mlayer\e\[0m=debugger'
+  while $RUNNING; do
+    # using `script` to keep colored output, and `exec` to get the PID from the
+    # subshell
+    script --flush --quiet "$DLV_OUTPUT_FILE" --command 'printf $$ > '"$DLV_PID_FILE && exec $DLV_CMD" &
+    SUBSHELL_PID=$!
+
+    # wait for either the subshell to die, or for the "halting" line to appear
+    # in the output
+    tail --follow --pid="$SUBSHELL_PID" --sleep-interval=0.1 "$DLV_OUTPUT_FILE" 2> /dev/null | grep --perl-regex --line-buffered "$HALTING_REGEX" | ( read && kill_delve )
+
+    wait "$SUBSHELL_PID"
+  done
+
+  rm -f "$DLV_PID_FILE" "$DLV_OUTPUT_FILE"
+}
+
+handle_interrupt() {
+  RUNNING=false
+  kill_delve
+}
+
+kill_delve() {
+  if [ -r "$DLV_PID_FILE" ]; then
+    local DLV_PID=$(cat "$DLV_PID_FILE")
+    [ "$DLV_PID" ] && kill "$DLV_PID" &> /dev/null
+  fi
+
+  [ "$SUBSHELL_PID" ] && kill $SUBSHELL_PID &> /dev/null
+}
+
+ensure_delve_installed() {
+  which dlv &> /dev/null || go get -u github.com/derekparker/delve/cmd/dlv
+}
+
+usage() {
+  echo "Usage: $0 name/of/go/package [additional dlv test options]"
+  exit 1
+}
+
+main "$@"