Adding a Dockerfile and making it easy to use it for dev

Credit goes to dperny (moby#2687)

**- What I did**

Adds a Dockerfile for the swarmkit project, to easily get off the ground. Modifies the Makefile to make intelligent use of Docker.

Also made small clean up changes to the Makefile.

**- How I did it**

Modifies the Makefile to have two paths: containerized.mk, which builds the docker image and forwards any make targets to a container, and direct.mk, which encompasses the old Makefile's workflow.

By default, nothing will run inside a container. Set the environment variable `DOCKER_SWARMKIT_USE_CONTAINER` to use dockerized making.

Also leverages docker-sync for synchronizing code to the container if the `DOCKER_SWARMKIT_USE_DOCKER_SYNC` env variable is set; comes in handy on Macs, for example.

**- How to test it**

Set `DOCKER_SWARMKIT_USE_CONTAINER` and verify that your favorite make targets all work!

.gitignore

@@ -31,3 +31,6 @@ bin/swarmkitstate
 
 # ignore code coverage output
 *coverage.txt
+
+# dev sync, if used
+/.docker-sync/

BUILDING.md

@@ -113,3 +113,15 @@ NB: As of version 3.0.0-7 the Debian `protobuf-compiler` package lacks
 a dependency on `libprotobuf-dev` which contains some standard proto
 definitions, be sure to install both packages. This is [Debian bug
 #842158](https://bugs.debian.org/842158).
+
+### Build in a container instead of your local environment
+
+You can also choose to use a container to build SwarmKit and run tests. Simply
+set the `DOCKER_SWARMKIT_USE_CONTAINER` environment variable to any value,
+export it, then run `make` targets as you would have done within your local
+environment.
+
+Additionally, if your OS is not Linux, you might want to set and export the
+`DOCKER_SWARMKIT_USE_DOCKER_SYNC` environment variable, which will make use of
+[docker-sync](https://github.com/EugenMayer/docker-sync) to sync the code to
+the container, instead of native mounted volumes.

Dockerfile

@@ -0,0 +1,30 @@
+# NOTE(dperny): for some reason, alpine was giving me trouble
+FROM golang:1.10.3-stretch
+
+RUN apt-get update && apt-get install -y make git unzip
+
+# should stay consistent with the version we use in Circle builds
+ARG PROTOC_VERSION=3.5.0
+# make a directory to do these operations in
+RUN export PROTOC_TMP_DIR=protoc && mkdir -p $PROTOC_TMP_DIR && cd $PROTOC_TMP_DIR \
+  # download the pre-built protoc binary
+  && curl --silent --show-error --location --output protoc.zip \
+    https://github.com/google/protobuf/releases/download/v$PROTOC_VERSION/protoc-$PROTOC_VERSION-linux-x86_64.zip \
+  # move the binary to /bin. move the well-known types ot /usr/local/include
+  && unzip protoc.zip && mv bin/protoc /bin/protoc && mv include/* /usr/local/include \
+  # remove all of the installation files
+  && cd .. && rm -rf $PROTOC_TMP_DIR
+
+WORKDIR /go/src/github.com/docker/swarmkit/
+
+# install the dependencies from `make setup`
+# we only copy `direct.mk` to avoid busting the cache too easily
+COPY direct.mk .
+RUN make --file=direct.mk setup
+
+# now we can copy the rest
+COPY . .
+
+# default to just `make`. If you want to change the default command, change the
+# default make command, not this command.
+CMD ["make"]

Makefile

@@ -24,136 +24,15 @@ VNDR=$(shell which vndr || echo '')
 
 GO_LDFLAGS=-ldflags "-X `go list ./version`.Version=$(VERSION)"
 
-.PHONY: clean all AUTHORS fmt vet lint build binaries test integration setup generate protos checkprotos coverage ci check help install uninstall dep-validate
-.DEFAULT: default
-
-all: check binaries test integration ## run fmt, vet, lint, build the binaries and run the tests
-
-check: fmt vet lint ineffassign misspell ## run fmt, vet, lint, ineffassign, misspell
-
-ci: check binaries checkprotos coverage coverage-integration ## to be used by the CI
-
-AUTHORS: .mailmap .git/HEAD
-	git log --format='%aN <%aE>' | sort -fu > $@
-
-# This only needs to be generated by hand when cutting full releases.
-version/version.go:
-	./version/version.sh > $@
-
-setup: ## install dependencies
-	@echo "🐳 $@"
-	# TODO(stevvooe): Install these from the vendor directory
-	@go get -u github.com/golang/lint/golint
-	#@go get -u github.com/kisielk/errcheck
-	@go get -u github.com/gordonklaus/ineffassign
-	@go get -u github.com/client9/misspell/cmd/misspell
-	@go get -u github.com/lk4d4/vndr
-	@go get -u github.com/stevvooe/protobuild
-
-generate: protos
-	@echo "🐳 $@"
-	@PATH=${ROOTDIR}/bin:${PATH} go generate -x ${PACKAGES}
-
-protos: bin/protoc-gen-gogoswarm ## generate protobuf
-	@echo "🐳 $@"
-	@PATH=${ROOTDIR}/bin:${PATH} protobuild ${PACKAGES}
-
-checkprotos: generate ## check if protobufs needs to be generated again
-	@echo "🐳 $@"
-	@test -z "$$(git status --short | grep ".pb.go" | tee /dev/stderr)" || \
-		((git diff | cat) && \
-		(echo "👹 please run 'make generate' when making changes to proto files" && false))
-
-# Depends on binaries because vet will silently fail if it can't load compiled
-# imports
-vet: binaries ## run go vet
-	@echo "🐳 $@"
-	@test -z "$$(go vet ${PACKAGES} 2>&1 | grep -v 'constant [0-9]* not a string in call to Errorf' | egrep -v '(timestamp_test.go|duration_test.go|exit status 1)' | tee /dev/stderr)"
-
-misspell:
-	@echo "🐳 $@"
-	@test -z "$$(find . -type f | grep -v vendor/ | grep -v bin/ | grep -v .git/ | grep -v MAINTAINERS | xargs misspell | tee /dev/stderr)"
-
-fmt: ## run go fmt
-	@echo "🐳 $@"
-	@test -z "$$(gofmt -s -l . | grep -v vendor/ | grep -v ".pb.go$$" | tee /dev/stderr)" || \
-		(echo "👹 please format Go code with 'gofmt -s -w'" && false)
-	@test -z "$$(find . -path ./vendor -prune -o ! -name timestamp.proto ! -name duration.proto -name '*.proto' -type f -exec grep -Hn -e "^ " {} \; | tee /dev/stderr)" || \
-		(echo "👹 please indent proto files with tabs only" && false)
-	@test -z "$$(find . -path ./vendor -prune -o -name '*.proto' -type f -exec grep -Hn "Meta meta = " {} \; | grep -v '(gogoproto.nullable) = false' | tee /dev/stderr)" || \
-		(echo "👹 meta fields in proto files must have option (gogoproto.nullable) = false" && false)
-
-lint: ## run go lint
-	@echo "🐳 $@"
-	@test -z "$$(golint ./... | grep -v vendor/ | grep -v ".pb.go:" | tee /dev/stderr)"
-
-ineffassign: ## run ineffassign
-	@echo "🐳 $@"
-	@test -z "$$(ineffassign . | grep -v vendor/ | grep -v ".pb.go:" | tee /dev/stderr)"
-
-#errcheck: ## run go errcheck
-#	@echo "🐳 $@"
-#	@test -z "$$(errcheck ./... | grep -v vendor/ | grep -v ".pb.go:" | tee /dev/stderr)"
-
-build: ## build the go packages
-	@echo "🐳 $@"
-	@go build -i -tags "${DOCKER_BUILDTAGS}" -v ${GO_LDFLAGS} ${GO_GCFLAGS} ${PACKAGES}
-
-test: ## run tests, except integration tests
-	@echo "🐳 $@"
-	@go test -parallel 8 ${RACE} -tags "${DOCKER_BUILDTAGS}" $(filter-out ${INTEGRATION_PACKAGE},${PACKAGES})
-
-integration: ## run integration tests
-	@echo "🐳 $@"
-	@go test -parallel 8 ${RACE} -tags "${DOCKER_BUILDTAGS}" ${INTEGRATION_PACKAGE}
-
-FORCE:
-
-# Build a binary from a cmd.
-bin/%: cmd/% FORCE
-	@test $$(go list) = "${PROJECT_ROOT}" || \
-		(echo "👹 Please correctly set up your Go build environment. This project must be located at <GOPATH>/src/${PROJECT_ROOT}" && false)
-	@echo "🐳 $@"
-	@go build -i -tags "${DOCKER_BUILDTAGS}" -o $@ ${GO_LDFLAGS}  ${GO_GCFLAGS} ./$<
-
-binaries: $(BINARIES) ## build binaries
-	@echo "🐳 $@"
-
-clean: ## clean up binaries
-	@echo "🐳 $@"
-	@rm -f $(BINARIES)
-
-install: $(BINARIES) ## install binaries
-	@echo "🐳 $@"
-	@mkdir -p $(DESTDIR)/bin
-	@install $(BINARIES) $(DESTDIR)/bin
-
-uninstall:
-	@echo "🐳 $@"
-	@rm -f $(addprefix $(DESTDIR)/bin/,$(notdir $(BINARIES)))
-
-coverage: ## generate coverprofiles from the unit tests
-	@echo "🐳 $@"
-	@( for pkg in $(filter-out ${INTEGRATION_PACKAGE},${PACKAGES}); do \
-		go test -i ${RACE} -tags "${DOCKER_BUILDTAGS}" -test.short -coverprofile="../../../$$pkg/coverage.txt" -covermode=atomic $$pkg || exit; \
-		go test ${RACE} -tags "${DOCKER_BUILDTAGS}" -test.short -coverprofile="../../../$$pkg/coverage.txt" -covermode=atomic $$pkg || exit; \
-	done )
-
-coverage-integration: ## generate coverprofiles from the integration tests
-	@echo "🐳 $@"
-	go test ${RACE} -tags "${DOCKER_BUILDTAGS}" -test.short -coverprofile="../../../${INTEGRATION_PACKAGE}/coverage.txt" -covermode=atomic ${INTEGRATION_PACKAGE}
-
-help: ## this help
-	@awk 'BEGIN {FS = ":.*?## "} /^[a-zA-Z_-]+:.*?## / {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}' $(MAKEFILE_LIST) | sort
-
-dep-validate:
-	@echo "+ $@"
-	$(if $(VNDR), , \
-		$(error Please install vndr: go get github.com/lk4d4/vndr))
-	@rm -Rf .vendor.bak
-	@mv vendor .vendor.bak
-	@$(VNDR)
-	@test -z "$$(diff -r vendor .vendor.bak 2>&1 | tee /dev/stderr)" || \
-		(echo >&2 "+ inconsistent dependencies! what you have in vendor.conf does not match with what you have in vendor" && false)
-	@rm -Rf vendor
-	@mv .vendor.bak vendor
+SHELL := /bin/bash
+
+# stop here. do we want to run everything inside of a container, or do we want
+# to run it directly on the host? if the user has set ANY non-empty value for
+# the variable DOCKER_SWARMKIT_USE_CONTAINER, then we do all of the making inside of
+# a container. We will default to using no container, to avoid breaking
+# anyone's workflow
+ifdef DOCKER_SWARMKIT_USE_CONTAINER
+include containerized.mk
+else
+include direct.mk
+endif

containerized.mk

@@ -0,0 +1,46 @@
+IMAGE_NAME=docker/swarmkit
+GOPATH=/go
+DOCKER_IMAGE_DIR=${GOPATH}/src/${PROJECT_ROOT}
+
+# 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
+# (see https://www.gnu.org/software/make/manual/html_node/Special-Targets.html)
+%::
+	@ echo "Running target $@ inside a container"
+	@ DOCKER_SWARMKIT_DOCKER_RUN_CMD="make $*" $(MAKE) run
+
+shell:
+	@ DOCKER_SWARMKIT_DOCKER_RUN_CMD='bash' DOCKER_SWARMKIT_DOCKER_RUN_FLAGS='-i' $(MAKE) run
+
+.PHONY: image
+image:
+	docker build -t ${IMAGE_NAME} .
+
+# internal target, only builds the image if it doesn't exist
+.PHONY: ensure_image_exists
+ensure_image_exists:
+	@ if [ ! $$(docker images -q ${IMAGE_NAME}) ]; then $(MAKE) image; fi
+
+# internal target, starts the sync if needed
+# uses https://github.com/EugenMayer/docker-sync/blob/47363ee31b71810a60b05822b9c4bd2176951ce8/tasks/sync/sync.thor#L193-L196
+# which is not great, but that's all they expose so far to do this...
+.PHONY: ensure_sync_started
+ensure_sync_started:
+	@ kill -0 $$(cat .docker-sync/daemon.pid) 2&> /dev/null || docker-sync start
+
+# internal target, actually runs a command inside a container
+# we don't use the `-i` flag for `docker run` by default as that makes it a pain to kill
+# running containers (can't kill with ctrl-c)
+.PHONY: run
+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="$$DOCKER_RUN_COMMAND -v swarmkit-sync:${DOCKER_IMAGE_DIR}"; \
+		else \
+			DOCKER_RUN_COMMAND="$$DOCKER_RUN_COMMAND -v ${ROOTDIR}:${DOCKER_IMAGE_DIR}"; \
+		fi \
+		&& DOCKER_RUN_COMMAND="$$DOCKER_RUN_COMMAND $$DOCKER_SWARMKIT_DOCKER_RUN_FLAGS ${IMAGE_NAME} $$DOCKER_SWARMKIT_DOCKER_RUN_CMD" \
+		&& echo $$DOCKER_RUN_COMMAND \
+		&& $$DOCKER_RUN_COMMAND