Build statically linked release executables.

Makefile

@@ -8,7 +8,7 @@ appname := weed
 
 sources := $(wildcard *.go)
 
-build = GOOS=$(1) GOARCH=$(2) go build -o build/$(appname)$(3) $(SOURCE_DIR)
+build = CGO_ENABLED=0 GOOS=$(1) GOARCH=$(2) go build -ldflags "-extldflags -static" -o build/$(appname)$(3) $(SOURCE_DIR)
 tar = cd build && tar -cvzf $(1)_$(2).tar.gz $(appname)$(3) && rm $(appname)$(3)
 zip = cd build && zip $(1)_$(2).zip $(appname)$(3) && rm $(appname)$(3)