refactor makefile: rename variables (including removal of "DOCKER_" prefixes)

Makefile

@@ -1,14 +1,14 @@
-DOCKER_IMAGE_NAME = docker.io/fphammerle/onion-service
-DOCKER_TAG_VERSION = $(shell git describe --match=v* --abbrev=0 --dirty | sed -e 's/^v//')
+IMAGE_NAME = docker.io/fphammerle/onion-service
+BUILD_VERSION = $(shell git describe --match=v* --abbrev=0 --dirty | sed -e 's/^v//')
 TOR_PACKAGE_VERSION = $(shell grep -Po 'TOR_PACKAGE_VERSION=\K.+' Dockerfile | tr -d -)
 ARCH = $(shell arch)
-DOCKER_TAG_ARCH_SUFFIX_aarch64 = arm64
-DOCKER_TAG_ARCH_SUFFIX_armv6l = armv6
-DOCKER_TAG_ARCH_SUFFIX_armv7l = armv7
-DOCKER_TAG_ARCH_SUFFIX_x86_64 = amd64
-DOCKER_TAG_ARCH_SUFFIX = ${DOCKER_TAG_ARCH_SUFFIX_${ARCH}}
-DOCKER_TAG = ${DOCKER_TAG_VERSION}-tor${TOR_PACKAGE_VERSION}-${DOCKER_TAG_ARCH_SUFFIX}
-BUILD_PARAMS = --tag="${DOCKER_IMAGE_NAME}:${DOCKER_TAG}" \
+IMAGE_TAG_ARCH_aarch64 = arm64
+IMAGE_TAG_ARCH_armv6l = armv6
+IMAGE_TAG_ARCH_armv7l = armv7
+IMAGE_TAG_ARCH_x86_64 = amd64
+IMAGE_TAG_ARCH = ${IMAGE_TAG_ARCH_${ARCH}}
+IMAGE_TAG = ${BUILD_VERSION}-tor${TOR_PACKAGE_VERSION}-${IMAGE_TAG_ARCH}
+BUILD_PARAMS = --tag="${IMAGE_NAME}:${IMAGE_TAG}" \
 	--build-arg=REVISION="$(shell git rev-parse HEAD)"
 
 .PHONY: docker-build podman-build docker-push
@@ -26,5 +26,5 @@ podman-build: worktree-clean
 	podman build --format=docker ${BUILD_PARAMS} .
 
 docker-push: docker-build
-	sudo docker push "${DOCKER_IMAGE_NAME}:${DOCKER_TAG}"
-	@echo git tag --sign --message '$(shell sudo docker image inspect --format '{{join .RepoDigests "\n"}}' "${DOCKER_IMAGE_NAME}:${DOCKER_TAG}")' docker/${DOCKER_TAG} $(shell git rev-parse HEAD)
+	sudo docker push "${IMAGE_NAME}:${IMAGE_TAG}"
+	@echo git tag --sign --message '$(shell sudo docker image inspect --format '{{join .RepoDigests "\n"}}' "${IMAGE_NAME}:${IMAGE_TAG}")' docker/${IMAGE_TAG} $(shell git rev-parse HEAD)