Add 'publish' target to tag and push release

weaver/Makefile

@@ -9,15 +9,19 @@ weaver: ../*.go main.go
 
 docker-image: /tmp/weave.tar
 
-# override this on the command-line when you are doing a release
-# e.g. make tag=0.99
-tag=dev
-
 /tmp/weave.tar: Dockerfile weaver
 	sudo docker build -t zettio/weave:latest .
-	sudo docker tag zettio/weave:latest zettio/weave:$(tag)
 	sudo docker save zettio/weave > /tmp/weave.tar
 
+# override this on the command-line when you are doing a release
+# e.g. make publish tag=0.99
+tag=latest
+
+publish: docker-image
+	git tag -a $(tag) -m "Release $(tag)"
+	sudo docker tag zettio/weave:latest zettio/weave:$(tag)
+	sudo docker push zettio/weave
+
 clean:
 	-sudo docker rmi zettio/weave
 	rm -f weaver pipework /tmp/weave.tar