go {build,test}: rm -i option, add go cache volume

Looks like -i (together with DOCKER_INCREMENTAL_BINARY etc)
were used to get faster incremental builds.

Nowdays (since Go 1.10) this is no longer the case, as
go build cache is used [1]. Here's a quote:

> You do not have to use "go test -i" or "go build -i" or
> "go install" just to get fast incremental builds. We will
> not have to teach new users those workarounds anymore.
> Everything will just be fast.

To enable go cache between builds, add a volume for /root/.cache.

[1] https://groups.google.com/forum/#!msg/golang-dev/qfa3mHN4ZPA/X2UzjNV1BAAJ

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

Makefile

@@ -1,10 +1,8 @@
-.PHONY: all binary dynbinary build cross help init-go-pkg-cache install manpages run shell test test-docker-py test-integration test-unit validate win
+.PHONY: all binary dynbinary build cross help install manpages run shell test test-docker-py test-integration test-unit validate win
 
 # set the graph driver as the current graphdriver if not set
 DOCKER_GRAPHDRIVER := $(if $(DOCKER_GRAPHDRIVER),$(DOCKER_GRAPHDRIVER),$(shell docker info 2>&1 | grep "Storage Driver" | sed 's/.*: //'))
 export DOCKER_GRAPHDRIVER
-DOCKER_INCREMENTAL_BINARY := $(if $(DOCKER_INCREMENTAL_BINARY),$(DOCKER_INCREMENTAL_BINARY),1)
-export DOCKER_INCREMENTAL_BINARY
 
 # get OS/Arch of docker engine
 DOCKER_OSARCH := $(shell bash -c 'source hack/make/.detect-daemon-osarch && echo $${DOCKER_ENGINE_OSARCH}')
@@ -38,7 +36,6 @@ DOCKER_ENVS := \
 	-e DOCKER_EXPERIMENTAL \
 	-e DOCKER_GITCOMMIT \
 	-e DOCKER_GRAPHDRIVER \
-	-e DOCKER_INCREMENTAL_BINARY \
 	-e DOCKER_LDFLAGS \
 	-e DOCKER_PORT \
 	-e DOCKER_REMAP_ROOT \
@@ -75,14 +72,10 @@ DOCKER_MOUNT := $(if $(DOCKER_MOUNT),$(DOCKER_MOUNT),-v /go/src/github.com/docke
 # This allows to set the docker-dev container name
 DOCKER_CONTAINER_NAME := $(if $(CONTAINER_NAME),--name $(CONTAINER_NAME),)
 
-# enable package cache if DOCKER_INCREMENTAL_BINARY and DOCKER_MOUNT (i.e.DOCKER_HOST) are set
-PKGCACHE_MAP := gopath:/go/pkg goroot-linux_amd64:/usr/local/go/pkg/linux_amd64 goroot-linux_amd64_netgo:/usr/local/go/pkg/linux_amd64_netgo
-PKGCACHE_VOLROOT := dockerdev-go-pkg-cache
-PKGCACHE_VOL := $(if $(PKGCACHE_DIR),$(CURDIR)/$(PKGCACHE_DIR)/,$(PKGCACHE_VOLROOT)-)
-DOCKER_MOUNT_PKGCACHE := $(if $(DOCKER_INCREMENTAL_BINARY),$(shell echo $(PKGCACHE_MAP) | sed -E 's@([^ ]*)@-v "$(PKGCACHE_VOL)\1"@g'),)
+DOCKER_MOUNT_CACHE := -v docker-dev-cache:/root/.cache
 DOCKER_MOUNT_CLI := $(if $(DOCKER_CLI_PATH),-v $(shell dirname $(DOCKER_CLI_PATH)):/usr/local/cli,)
 DOCKER_MOUNT_BASH_COMPLETION := $(if $(DOCKER_BASH_COMPLETION_PATH),-v $(shell dirname $(DOCKER_BASH_COMPLETION_PATH)):/usr/local/completion/bash,)
-DOCKER_MOUNT := $(DOCKER_MOUNT) $(DOCKER_MOUNT_PKGCACHE) $(DOCKER_MOUNT_CLI) $(DOCKER_MOUNT_BASH_COMPLETION)
+DOCKER_MOUNT := $(DOCKER_MOUNT) $(DOCKER_MOUNT_CACHE) $(DOCKER_MOUNT_CLI) $(DOCKER_MOUNT_BASH_COMPLETION)
 
 GIT_BRANCH := $(shell git rev-parse --abbrev-ref HEAD 2>/dev/null)
 GIT_BRANCH_CLEAN := $(shell echo $(GIT_BRANCH) | sed -e "s/[^[:alnum:]]/-/g")
@@ -124,19 +117,19 @@ binary: build ## build the linux binaries
 dynbinary: build ## build the linux dynbinaries
 	$(DOCKER_RUN_DOCKER) hack/make.sh dynbinary
 
-build: bundles init-go-pkg-cache
+build: bundles
 	$(warning The docker client CLI has moved to github.com/docker/cli. For a dev-test cycle involving the CLI, run:${\n} DOCKER_CLI_PATH=/host/path/to/cli/binary make shell ${\n} then change the cli and compile into a binary at the same location.${\n})
 	docker build ${BUILD_APT_MIRROR} ${DOCKER_BUILD_ARGS} -t "$(DOCKER_IMAGE)" -f "$(DOCKERFILE)" .
 
 bundles:
 	mkdir bundles
 
-clean: clean-pkg-cache-vol ## clean up cached resources
+.PHONY: clean
+clean: clean-cache
 
-clean-pkg-cache-vol:
-	@- $(foreach mapping,$(PKGCACHE_MAP), \
-		$(shell docker volume rm $(PKGCACHE_VOLROOT)-$(shell echo $(mapping) | awk -F':/' '{ print $$1 }') > /dev/null 2>&1) \
-	)
+.PHONY: clean-cache
+clean-cache:
+	docker volume rm -f docker-dev-cache
 
 cross: build ## cross build the binaries for darwin, freebsd and\nwindows
 	$(DOCKER_RUN_DOCKER) hack/make.sh dynbinary binary cross
@@ -144,9 +137,6 @@ cross: build ## cross build the binaries for darwin, freebsd and\nwindows
 help: ## this help
 	@awk 'BEGIN {FS = ":.*?## "} /^[a-zA-Z_-]+:.*?## / {sub("\\\\n",sprintf("\n%22c"," "), $$2);printf "\033[36m%-20s\033[0m %s\n", $$1, $$2}' $(MAKEFILE_LIST)
 
-init-go-pkg-cache:
-	$(if $(PKGCACHE_DIR), mkdir -p $(shell echo $(PKGCACHE_MAP) | sed -E 's@([^: ]*):[^ ]*@$(PKGCACHE_DIR)/\1@g'))
-
 install: ## install the linux binaries
 	KEEPBUNDLE=1 hack/make.sh install-binary
 
@@ -197,12 +187,11 @@ build-integration-cli-on-swarm: build ## build images and binary for running int
 	go build -buildmode=pie -o ./hack/integration-cli-on-swarm/integration-cli-on-swarm ./hack/integration-cli-on-swarm/host
 	@echo "Building $(INTEGRATION_CLI_MASTER_IMAGE)"
 	docker build -t $(INTEGRATION_CLI_MASTER_IMAGE) hack/integration-cli-on-swarm/agent
-# For worker, we don't use `docker build` so as to enable DOCKER_INCREMENTAL_BINARY and so on
 	@echo "Building $(INTEGRATION_CLI_WORKER_IMAGE) from $(DOCKER_IMAGE)"
 	$(eval tmp := integration-cli-worker-tmp)
 # We mount pkgcache, but not bundle (bundle needs to be baked into the image)
 # For avoiding bakings DOCKER_GRAPHDRIVER and so on to image, we cannot use $(DOCKER_ENVS) here
-	docker run -t -d --name $(tmp) -e DOCKER_GITCOMMIT -e BUILDFLAGS -e DOCKER_INCREMENTAL_BINARY --privileged $(DOCKER_MOUNT_PKGCACHE) $(DOCKER_IMAGE) top
+	docker run -t -d --name $(tmp) -e DOCKER_GITCOMMIT -e BUILDFLAGS --privileged $(DOCKER_IMAGE) top
 	docker exec $(tmp) hack/make.sh build-integration-test-binary dynbinary
 	docker exec $(tmp) go build -buildmode=pie -o /worker github.com/docker/docker/hack/integration-cli-on-swarm/agent/worker
 	docker commit -c 'ENTRYPOINT ["/worker"]' $(tmp) $(INTEGRATION_CLI_WORKER_IMAGE)

docs/contributing/set-up-dev-env.md

@@ -130,7 +130,7 @@ can take over 15 minutes to complete.
    ```none
    Successfully built 3d872560918e
    Successfully tagged docker-dev:dry-run-test
-   docker run --rm -i --privileged -e BUILDFLAGS -e KEEPBUNDLE -e DOCKER_BUILD_GOGC -e DOCKER_BUILD_PKGS -e DOCKER_CLIENTONLY -e DOCKER_DEBUG -e DOCKER_EXPERIMENTAL -e DOCKER_GITCOMMIT -e DOCKER_GRAPHDRIVER=devicemapper -e DOCKER_INCREMENTAL_BINARY -e DOCKER_REMAP_ROOT -e DOCKER_STORAGE_OPTS -e DOCKER_USERLANDPROXY -e TESTDIRS -e TESTFLAGS -e TIMEOUT -v "home/ubuntu/repos/docker/bundles:/go/src/github.com/docker/docker/bundles" -t "docker-dev:dry-run-test" bash
+   docker run --rm -i --privileged -e BUILDFLAGS -e KEEPBUNDLE -e DOCKER_BUILD_GOGC -e DOCKER_BUILD_PKGS -e DOCKER_CLIENTONLY -e DOCKER_DEBUG -e DOCKER_EXPERIMENTAL -e DOCKER_GITCOMMIT -e DOCKER_GRAPHDRIVER=devicemapper -e DOCKER_REMAP_ROOT -e DOCKER_STORAGE_OPTS -e DOCKER_USERLANDPROXY -e TESTDIRS -e TESTFLAGS -e TIMEOUT -v "home/ubuntu/repos/docker/bundles:/go/src/github.com/docker/docker/bundles" -t "docker-dev:dry-run-test" bash
    #
    ```
 

hack/integration-cli-on-swarm/README.md

@@ -36,7 +36,6 @@ while the client is supposed to be running on a laptop, e.g. Docker for Mac/Wind
 Following environment variables are known to work in this step:
 
  - `BUILDFLAGS`
- - `DOCKER_INCREMENTAL_BINARY`
 
 Note: during the transition into Moby Project, you might need to create a symbolic link `$GOPATH/src/github.com/docker/docker` to `$GOPATH/src/github.com/moby/moby`. 
 

hack/make.sh

@@ -148,14 +148,6 @@ EXTLDFLAGS_STATIC='-static'
 ORIG_BUILDFLAGS=( -tags "autogen netgo osusergo static_build $DOCKER_BUILDTAGS" -installsuffix netgo )
 # see https://github.com/golang/go/issues/9369#issuecomment-69864440 for why -installsuffix is necessary here
 
-# When $DOCKER_INCREMENTAL_BINARY is set in the environment, enable incremental
-# builds by installing dependent packages to the GOPATH.
-REBUILD_FLAG="-a"
-if [ "$DOCKER_INCREMENTAL_BINARY" == "1" ] || [ "$DOCKER_INCREMENTAL_BINARY" == "true" ]; then
-	REBUILD_FLAG="-i"
-fi
-ORIG_BUILDFLAGS+=( $REBUILD_FLAG )
-
 BUILDFLAGS=( $BUILDFLAGS "${ORIG_BUILDFLAGS[@]}" )
 
 # Test timeout.

hack/test/unit

@@ -19,10 +19,6 @@ TESTDIRS="${TESTDIRS:-"./..."}"
 exclude_paths="/vendor/|/integration"
 pkg_list=$(go list $TESTDIRS | grep -vE "($exclude_paths)")
 
-# install test dependencies once before running tests for each package. This
-# significantly reduces the runtime.
-go test -i "${BUILDFLAGS[@]}" $pkg_list
-
 for pkg in $pkg_list; do
     go test "${BUILDFLAGS[@]}" \
         -cover \