Fix and refactor Makefile and .goreleaser build commands.

The earlier goreleaser implementation was incorrect where every
build would trigger `make pack-release` with the list of all
cross-platform releases. Fix that to atomically run the packing
once per goreleaser build. In addition, add `make release-dry`
and `make release` for goreleaser.

.goreleaser.yml

@@ -1,7 +1,6 @@
 env:
   - GO111MODULE=on
   - CGO_ENABLED=0
-  - RELEASE_BUILDS=dist/listmonk_darwin_amd64/listmonk dist/listmonk_linux_amd64/listmonk dist/listmonk_windows_amd64/listmonk.exe
 
 before:
   hooks:
@@ -21,7 +20,7 @@ builds:
 
     hooks:
       # stuff executables with static assets.
-      post: make pack-releases
+      post: make pack-bin bin={{ .Path }}
 
 archives:
   - format: tar.gz

Makefile

@@ -11,43 +11,55 @@ STATIC := config.toml.sample \
 	frontend/dist/favicon.png:/frontend/favicon.png \
 	frontend/dist/frontend:/frontend
 
-# Dependencies.
+# Install dependencies for building.
 .PHONY: deps
 deps:
 	go get -u github.com/knadh/stuffbin/...
 	cd frontend && yarn install
 
-# Build steps.
+# Build the backend to ./listmonk.
 .PHONY: build
 build:
 	go build -o ${BIN} -ldflags="-s -w -X 'main.buildString=${BUILDSTR}' -X 'main.versionString=${VERSION}'" cmd/*.go
 
-.PHONY: build-frontend
-build-frontend:
-	export VUE_APP_VERSION="${VERSION}" && cd frontend && yarn build
-
+# Run the backend.
 .PHONY: run
 run: build
 	./${BIN}
 
+# Build the JS frontend into frontend/dist.
+.PHONY: build-frontend
+build-frontend:
+	export VUE_APP_VERSION="${VERSION}" && cd frontend && yarn build
+
+# Run the JS frontend server in dev mode.
 .PHONY: run-frontend
 run-frontend:
 	export VUE_APP_VERSION="${VERSION}" && cd frontend && yarn serve
 
+# Run Go tests.
 .PHONY: test
 test:
 	go test ./...
 
-# dist builds the backend, frontend, and uses stuffbin to
-# embed all frontend assets into the binary.
+# Bundle all static assets including the JS frontend into the ./listmonk binary
+# using stuffbin (installed with make deps).
 .PHONY: dist
 dist: build build-frontend
 	stuffbin -a stuff -in ${BIN} -out ${BIN} ${STATIC}
 
-# pack-releases runns stuffbin packing on a given list of
-# binaries. This is used with goreleaser for packing
-# release builds for cross-build targets.
-.PHONY: pack-releases
-pack-releases:
-	$(foreach var,$(RELEASE_BUILDS),stuffbin -a stuff -in ${var} -out ${var} ${STATIC};)
+# pack-releases runns stuffbin packing on the given binary. This is used
+# in the .goreleaser post-build hook.
+.PHONY: pack-bin
+pack-bin:
+	stuffbin -a stuff -in $(bin) -out $(bin) ${STATIC}
 
+# Use goreleaser to do a dry run producing local builds.
+.PHONY: release-dry
+release-dry:
+	goreleaser --parallelism 1 --rm-dist --snapshot --skip-validate --skip-publish
+
+# Use goreleaser to build production releases and publish them.
+.PHONY: release
+release:
+	goreleaser --parallelism 1 --rm-dist --skip-validate