Restoring fetch-dist and sign Make targets

These make targets are used as part of the release process. They
had yet to be brought over to the v3 branch from the v2 branch
as they were developed after the branching happened.

Signed-off-by: Matt Farina <matt@mattfarina.com>

Makefile

@@ -1,7 +1,8 @@
-BINDIR     := $(CURDIR)/bin
-DIST_DIRS  := find * -type d -exec
-TARGETS    := darwin/amd64 linux/amd64 linux/386 linux/arm linux/arm64 linux/ppc64le windows/amd64
-BINNAME    ?= helm
+BINDIR      := $(CURDIR)/bin
+DIST_DIRS   := find * -type d -exec
+TARGETS     := darwin/amd64 linux/amd64 linux/386 linux/arm linux/arm64 linux/ppc64le windows/amd64
+TARGET_OBJS ?= darwin-amd64.tar.gz darwin-amd64.tar.gz.sha256 linux-amd64.tar.gz linux-amd64.tar.gz.sha256 linux-386.tar.gz linux-386.tar.gz.sha256 linux-arm.tar.gz linux-arm.tar.gz.sha256 linux-arm64.tar.gz linux-arm64.tar.gz.sha256 linux-ppc64le.tar.gz linux-ppc64le.tar.gz.sha256 windows-amd64.zip windows-amd64.zip.sha256
+BINNAME     ?= helm
 
 GOPATH        = $(shell go env GOPATH)
 DEP           = $(GOPATH)/bin/dep
@@ -138,6 +139,20 @@ dist:
 		$(DIST_DIRS) zip -r helm-${VERSION}-{}.zip {} \; \
 	)
 
+.PHONY: fetch-dist
+fetch-dist:
+	mkdir -p _dist
+	cd _dist && \
+	for obj in ${TARGET_OBJS} ; do \
+		curl -sSL -o helm-${VERSION}-$${obj} https://get.helm.sh/helm-${VERSION}-$${obj} ; \
+	done
+
+.PHONY: sign
+sign:
+	for f in _dist/*.{gz,zip,sha256} ; do \
+		gpg --armor --detach-sign $${f} ; \
+	done
+
 .PHONY: checksum
 checksum:
 	for f in _dist/*.{gz,zip} ; do \