feat: reorganize project layout + switch to cayley

Based on https://manfred.life/golang-project-layout

Makefile

@@ -1,13 +1,64 @@
 GOPKG ?= 	moul.io/depviz
-GOBINS ?=	. ./tools/opml-to-github-issues ./tools/sed-i-github-issues
+GOBINS =	./cmd/depviz
+#GOBINS += ./tools/opml-to-github-issues
+#GOBINS += ./tools/sed-i-github-issues
 DOCKER_IMAGE ?=	moul/depviz
 
+
 all: test install
 
+
+PRE_INSTALL_STEPS += generate
+PRE_TEST_STEPS += generate
+PRE_BUILD_STEPS += generate
+PRE_LING_STEPS += generate
+PRE_BUMPDEPS_STEPS += generate
 include rules.mk
 
+
 .PHONY: update_examples
 update_examples:
 	for dir in $(sort $(dir $(wildcard examples/*/*))); do (cd $$dir && make); done
 	@echo "now you can run:"
 	@echo "    git commit examples -m \"chore: update examples\""
+
+
+##
+## generate
+##
+
+
+PROTOS_SRC := $(wildcard ./api/*.proto) $(wildcard ./api/internal/*.proto)
+GEN_SRC := $(PROTOS_SRC) Makefile
+.PHONY: generate
+generate: gen.sum
+gen.sum: $(GEN_SRC)
+	shasum $(GEN_SRC) | sort > gen.sum.tmp
+	diff -q gen.sum gen.sum.tmp || ( \
+	  set -e; \
+	  GO111MODULE=on go mod vendor; \
+	  docker run \
+	    --user=`id -u` \
+	    --volume="$(PWD):/go/src/moul.io/depviz" \
+	    --workdir="/go/src/moul.io/depviz" \
+	    --entrypoint="sh" \
+	    --rm \
+	    moul/depviz-protoc:1 \
+	    -xec 'make generate_local'; \
+	    make tidy \
+	)
+
+
+.PHONY: generate_local
+generate_local:
+	@set -e; for proto in $(PROTOS_SRC); do ( set -xe; \
+	  protoc -I ./api:./vendor:/protobuf --grpc-gateway_out=logtostderr=true:"$(GOPATH)/src" --gogofaster_out="plugins=grpc:$(GOPATH)/src" "$$proto" \
+	); done
+	goimports -w ./pkg ./cmd ./internal
+	shasum $(GEN_SRC) | sort > gen.sum.tmp
+	mv gen.sum.tmp gen.sum
+
+
+.PHONY: clean
+clean:
+	rm -f gen.sum $(wildcard */*/*.pb.go */*/*.pb.gw.go) $(wildcard out/*)