Explicitly list the tags to push

The default behavior in Docker 20.10 changed, so that `docker push`
will only push the `latest` tag rather than all tags. Upstream did add
an option flag to support the previous behavior (`--all-tags`), but
explicitly listing the desired tags is more understandable and ensures
backward compatibility.

See:
- docker/cli#2214
- https://www.docker.com/blog/introducing-docker-engine-20-10/

Makefile

@@ -1,5 +1,10 @@
 DOCKER_HUB_REPOSITORY ?= elasticdog
 
+UNIQUE_TAG := $(shell printf '%s.%s' "$$(date +%Y%m%d)" "$${CIRCLE_BUILD_NUM:-$$(git rev-parse --short=12 HEAD)}")
+PATCH_VERSION := $(shell docker run -it --rm tiddlywiki --version | sed 's/[^0-9.]*//g')
+MINOR_VERSION := $(shell echo "${PATCH_VERSION}" | awk -F. '{ print $$1"."$$2 }')
+MAJOR_VERSION := $(shell echo "${PATCH_VERSION}" | awk -F. '{ print $$1 }')
+
 .PHONY: all
 all: build
 
@@ -13,10 +18,6 @@ test:
 	cd tests/ && dgoss run tiddlywiki --listen
 
 .PHONY: tag
-tag: UNIQUE_TAG = $(shell printf '%s.%s' "$$(date +%Y%m%d)" "$${CIRCLE_BUILD_NUM:-$$(git rev-parse --short=12 HEAD)}")
-tag: PATCH_VERSION = $(shell docker run -it --rm tiddlywiki --version | sed 's/[^0-9.]*//g')
-tag: MINOR_VERSION = $(shell echo "${PATCH_VERSION}" | awk -F. '{ print $$1"."$$2 }')
-tag: MAJOR_VERSION = $(shell echo "${PATCH_VERSION}" | awk -F. '{ print $$1 }')
 tag:
 	# unique tag
 	docker tag tiddlywiki "${DOCKER_HUB_REPOSITORY}/tiddlywiki:${UNIQUE_TAG}"
@@ -29,7 +30,13 @@ tag:
 
 .PHONY: deploy
 deploy: tag
-	docker push "${DOCKER_HUB_REPOSITORY}/tiddlywiki"
+	# unique tag
+	docker push "${DOCKER_HUB_REPOSITORY}/tiddlywiki:${UNIQUE_TAG}"
+	# stable tags
+	docker push "${DOCKER_HUB_REPOSITORY}/tiddlywiki:latest"
+	docker push "${DOCKER_HUB_REPOSITORY}/tiddlywiki:${PATCH_VERSION}"
+	docker push "${DOCKER_HUB_REPOSITORY}/tiddlywiki:${MINOR_VERSION}"
+	docker push "${DOCKER_HUB_REPOSITORY}/tiddlywiki:${MAJOR_VERSION}"
 
 .PHONY: clean
 clean: