Makefile: Add deploy target, which pushes the resulting OCI image

This corrects ci behaviour, allowing this image to now be used like this:

docker run --rm -it guix-builder:latest <cmd>

Where <cmd> is any executable on the containers PATH.

Dockerfile

@@ -11,4 +11,4 @@ ENV PROOT_TMP_DIR=/tmp/proot
 RUN rm /tmp/proot/delete-me
 
 VOLUME /var/guix/daemon-socket/socket /gnu/store /etc/ssl
-ENTRYPOINT ["/guix-builder/bin/bash"]
+CMD ["/guix-builder/bin/bash"]

Makefile

@@ -6,7 +6,12 @@ GUIX_MANIFEST_DEV := manifest-dev.scm
 TARBALL ?= guix-tarball-pack.tar.gz
 LINKS_TARBALL ?= links.tar.gz
 PASSWD_FILE ?= passwd
-IMAGE_TAG ?= guix-builder
+
+OCI_REGISTRY ?= docker-local.nexus.home.rekahsoft.ca
+IMAGE_NAME ?= guix-builder
+IMAGE_TAG ?= latest
+LOCAL_IMAGE_NAME := $(IMAGE_NAME):$(IMAGE_TAG)
+PUSH_IMAGE_NAME := $(OCI_REGISTRY)/$(LOCAL_IMAGE_NAME)
 
 $(PASSWD_FILE):
 	echo 'root:x:0:0:root:/root:/bin/sh' > passwd
@@ -30,7 +35,7 @@ pre-build: $(TARBALL) $(LINKS_TARBALL) $(PASSWD_FILE)
 
 .PHONY: build
 build: pre-build
-	@docker build -t $(IMAGE_TAG) .
+	@docker build -t $(IMAGE_NAME) .
 
 .PHONY: run
 run: build
@@ -38,16 +43,21 @@ run: build
           -v /var/guix/daemon-socket/socket:/var/guix/daemon-socket/socket \
           -v /gnu/store:/gnu/store:ro \
           -v /etc/ssl:/etc/ssl:ro \
-          $(IMAGE_TAG):latest
+          $(IMAGE_NAME):latest
 
 .PHONY: run-no-store
 run-no-store: build
-	@docker run --rm -it $(IMAGE_TAG):latest
+	@docker run --rm -it $(IMAGE_NAME):latest
 
 .PHONY: shell
 shell:
 	@./shell.sh $(GUIX_MANIFEST) $(GUIX_MANIFEST_DEV)
 
-.PHONY:
+.PHONY: clean
 clean:
 	rm -r $(TARBALL) $(LINKS_TARBALL) $(PASSWD_FILE)
+
+.PHONY: deploy
+deploy:
+	docker tag $(IMAGE_NAME) $(PUSH_IMAGE_NAME)
+	docker push $(PUSH_IMAGE_NAME)