Add Makefile for envoy Docker image

Change-Id: I47d2d6f85248d80d1a60b3c4bc0da1e0d04627d9
diff --git a/docker/envoy/Makefile b/docker/envoy/Makefile
new file mode 100644
index 0000000..0b38d59
--- /dev/null
+++ b/docker/envoy/Makefile
@@ -0,0 +1,12 @@
+MUTABLE_VERSION ?= latest
+VERSION ?= $(shell git rev-parse --short HEAD)
+
+IMAGE_INTERNAL := docker-registry.corp.avm99963.com/twpt-server-envoy
+
+docker-internal: Dockerfile
+	docker build --force-rm -f Dockerfile --tag $(IMAGE_INTERNAL):$(VERSION) .
+	docker tag $(IMAGE_INTERNAL):$(VERSION) $(IMAGE_INTERNAL):$(MUTABLE_VERSION)
+
+push-internal: docker-internal
+	docker push $(IMAGE_INTERNAL):$(VERSION)
+	docker push $(IMAGE_INTERNAL):$(MUTABLE_VERSION)