[BUILD] Minimize docker container sizes

We use two techniques:

1) the use of a minimal docker base (FROM scratch + busybox)
2) the use of a static binary

 ... to create a minimally sized image for 'peer' and 'orderer'

Before this patch, these containers are approximately 1.4GB.  After this
patch, they are about 20MB-24MB.

It isn't strictly necessary to include busybox.  The main benefit
is achieved simply by eliminating external dependencies in the
golang binary using -static and then getting rid of all the
bloat in the baseimage via "FROM scratch".  However, in this mode
the image is pathologically bare-boned.  For instance, the image has
to be launched using the exec-form '["peer", "node", "start"]' since
there is no shell interpreter available to do the more natural
"CMD peer node start".  Further, any "docker exec" style debugging
would be impossible.  It is often helpful to jump into a container
and poke around with tools like ifconfig, ping, netstat, etc.

Enter busybox: We can create a basic unix environment with only
a 5MB payload.  This is impressive and is easily worth its weight
in the image.

However, the challenge isn't really justifying the utility of having
busybox over saving 5MB as much as it is about how we will get it
into the image.  If the world were a monochrome x86_64, we could simply
s/FROM scratch/FROM busybox and be done.  However, we have to consider
other multi $arch.  To support this, we forgo the temptation to use
FROM busybox and build busybox from source.  On my 2011 Macbook Pro,
this adds about 5 minutes to the build, at least on the first build.
Subsequent builds utilize the cache in ./build and thus are no-ops.

This is _just_ fast enough that I am not embarrassed to propose it
for consideration.  However, if this is perceived as a problem
we do have alternatives.  For instance, we could start distributing
a multi-$arch busybox base (hyperledger/fabric-busybox:$arch), TBD.

Change-Id: I4ed20a429c2cc2e72fd602b45c5c8dd5548bc995
Signed-off-by: Greg Haskins <gregory.haskins@gmail.com>

Makefile

@@ -49,6 +49,7 @@ endif
 PKGNAME = github.com/$(PROJECT_NAME)
 GO_LDFLAGS = -X $(PKGNAME)/metadata.Version=$(PROJECT_VERSION)
 CGO_FLAGS = CGO_CFLAGS=" "
+GO_DOCKER_FLAGS= -ldflags "$(GO_LDFLAGS) -linkmode external -extldflags '-static -lpthread'"
 ARCH=$(shell uname -m)
 OS=$(shell uname)
 CHAINTOOL_RELEASE=v0.10.0
@@ -100,7 +101,7 @@ GOSHIM_DEPS = $(shell ./scripts/goListFiles.sh $(PKGNAME)/core/chaincode/shim |
 JAVASHIM_DEPS =  $(shell git ls-files core/chaincode/shim/java)
 PROTOS = $(shell git ls-files *.proto | grep -v vendor)
 PROJECT_FILES = $(shell git ls-files)
-IMAGES = peer orderer ccenv javaenv testenv
+IMAGES = peer orderer ccenv javaenv testenv runtime
 
 pkgmap.peer           := $(PKGNAME)/peer
 pkgmap.orderer        := $(PKGNAME)/orderer
@@ -160,12 +161,12 @@ linter: testenv
 build/docker/bin/%: $(PROJECT_FILES)
 	$(eval TARGET = ${patsubst build/docker/bin/%,%,${@}})
 	@echo "Building $@"
-	@mkdir -p build/docker/bin build/docker/pkg
+	@mkdir -p build/docker/bin build/docker/$(TARGET)/pkg
 	@$(DRUN) \
 		-v $(abspath build/docker/bin):/opt/gopath/bin \
-		-v $(abspath build/docker/pkg):/opt/gopath/pkg \
+		-v $(abspath build/docker/$(TARGET)/pkg):/opt/gopath/pkg \
 		hyperledger/fabric-baseimage:$(BASE_DOCKER_TAG) \
-		go install -ldflags "$(GO_LDFLAGS)" $(pkgmap.$(@F))
+		go install $(GO_DOCKER_FLAGS) $(pkgmap.$(@F))
 	@touch $@
 
 build/bin:
@@ -181,10 +182,19 @@ build/docker/gotools: gotools/Makefile
 		hyperledger/fabric-baseimage:$(BASE_DOCKER_TAG) \
 		make install BINDIR=/opt/gotools/bin OBJDIR=/opt/gotools/obj
 
-# Both peer and peer-docker depend on ccenv and javaenv (all docker env images it supports)
+build/docker/busybox:
+	@$(DRUN) \
+		hyperledger/fabric-baseimage:$(BASE_DOCKER_TAG) \
+		make -f busybox/Makefile install BINDIR=$(@D)
+
+# Both peer and peer-docker depend on ccenv and javaenv (all docker env images it supports).
 build/bin/peer: build/image/ccenv/.dummy build/image/javaenv/.dummy
 build/image/peer/.dummy: build/image/ccenv/.dummy build/image/javaenv/.dummy
 
+# Both peer-docker and orderer-docker depend on the runtime image
+build/image/peer/.dummy: build/image/runtime/.dummy
+build/image/orderer/.dummy: build/image/runtime/.dummy
+
 build/bin/%: $(PROJECT_FILES)
 	@mkdir -p $(@D)
 	@echo "$@"
@@ -205,6 +215,7 @@ build/image/peer/payload:       build/docker/bin/peer \
 build/image/orderer/payload:    build/docker/bin/orderer \
 				orderer/orderer.yaml
 build/image/testenv/payload:    build/gotools.tar.bz2
+build/image/runtime/payload:    build/docker/busybox
 
 build/image/%/payload:
 	mkdir -p $@

busybox/Makefile

@@ -0,0 +1,27 @@
+BUSYBOX_VER=1.25.1
+BUSYBOX_URL=https://www.busybox.net/downloads/busybox-$(BUSYBOX_VER).tar.bz2
+
+OBJDIR=build/busybox-$(BUSYBOX_VER)
+
+all: $(OBJDIR)/busybox
+
+install: $(BINDIR)/busybox
+
+$(BINDIR)/busybox: $(OBJDIR)/busybox
+	mkdir -p $(@D)
+	cp $< $@
+
+$(OBJDIR)/.source:
+	mkdir -p $(@D)
+	curl -L $(BUSYBOX_URL) | (cd $(@D); tar --strip-components=1 -jx)
+	touch $@
+
+$(OBJDIR)/.config: $(OBJDIR)/.source
+	make -C $(@D) defconfig
+
+$(OBJDIR)/busybox: Makefile $(OBJDIR)/.config
+	make -C $(@D) -l 2.5 -j all LDFLAGS=-static
+
+clean:
+	-rm -rf $(OBJDIR)
+

images/orderer/Dockerfile.in

@@ -1,4 +1,4 @@
-FROM hyperledger/fabric-baseimage:_BASE_TAG_
+FROM hyperledger/fabric-runtime:_TAG_
 ENV ORDERER_CFG_PATH /etc/hyperledger/fabric
 RUN mkdir -p /var/hyperledger/db /etc/hyperledger/fabric
 COPY payload/orderer /usr/local/bin

images/peer/Dockerfile.in

@@ -1,4 +1,4 @@
-FROM hyperledger/fabric-baseimage:_BASE_TAG_
+FROM hyperledger/fabric-runtime:_TAG_
 ENV PEER_CFG_PATH /etc/hyperledger/fabric
 RUN mkdir -p /var/hyperledger/db $PEER_CFG_PATH/msp
 COPY payload/peer /usr/local/bin

images/runtime/Dockerfile.in

@@ -0,0 +1,6 @@
+FROM scratch
+COPY payload/busybox /bin/busybox
+RUN ["/bin/busybox", "mkdir", "-p", "/usr/bin", "/sbin", "/usr/sbin"]
+RUN ["/bin/busybox", "--install"]
+RUN mkdir -p /usr/local/bin
+ENV PATH=$PATH:/usr/local/bin