Versioning: Get the version from the right place

The "hyper" calico changes meant that startup.go would never get a
version populated.

Instead, let's just get versioning information from one place. It can't
be "main" since startup can't import that, so at build time just store
the version in startup.VERSION then the version command in main.go can
retrieve it from there.

Makefile

@@ -117,7 +117,7 @@ MAKE_SURE_BIN_EXIST := $(shell mkdir -p dist .go-pkg-cache $(NODE_CONTAINER_BIN_
 NODE_CONTAINER_FILES=$(shell find ./filesystem -type f)
 SRCFILES=$(shell find ./pkg -name '*.go')
 LOCAL_USER_ID?=$(shell id -u $$USER)
-LDFLAGS=-ldflags "-X main.VERSION=$(CALICO_GIT_VER)"
+LDFLAGS=-ldflags "-X github.com/projectcalico/node/pkg/startup.VERSION=$(CALICO_GIT_VER)"
 PACKAGE_NAME?=github.com/projectcalico/node
 LIBCALICOGO_PATH?=none
 

cmd/calico-node/main.go

@@ -30,9 +30,6 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
-// Populated by build - used for printing version.
-var VERSION string
-
 // Create a new flag set.
 var flagSet = flag.NewFlagSet("Calico", flag.ContinueOnError)
 
@@ -89,7 +86,7 @@ func main() {
 
 	// Decide which action to take based on the given flags.
 	if *version {
-		fmt.Println(VERSION)
+		fmt.Println(startup.VERSION)
 		os.Exit(0)
 	} else if *runFelix {
 		felix.Run("/etc/calico/felix.cfg")