Modernize the makefile for the docker image.

docker/server/Makefile

@@ -1,35 +1,51 @@
+SHELL := bash
+.ONESHELL:
+.SHELLFLAGS := -eu -o pipefail -c
+.DELETE_ON_ERROR:
+MAKEFLAGS += --warn-undefined-variables
+MAKEFLAGS += --no-builtin-rules
+OS:=$(shell uname -s)
+
+ifeq ($(origin .RECIPEPREFIX), undefined)
+  $(error This Make does not support .RECIPEPREFIX. Please use GNU Make 4.0 or later)
+endif
+.RECIPEPREFIX = >
+
 IMAGE_NAME:=homepage
 # REMOTE_REPO:=harbor.fizz.buzz/private
+TARGET :=
 
-.PHONY: all
-all: build push
+.PHONY: help
+help:
+> @grep -h "##" $(MAKEFILE_LIST) | grep -v grep | sed -E 's/^([^:]*): *## */\1:  /'
 
 .PHONY: build
-build:
-	docker build -t $(IMAGE_NAME) -f Dockerfile ../../
+build: ## Build the docker image.
+> docker build --tag $(IMAGE_NAME) --target=$(TARGET) --file Dockerfile ../../
 
 .PHONY: push
-push:
+push: ## Push the docker image to a remote repository.
 ifdef REMOTE_REPO
-	docker tag $(IMAGE_NAME) $(REMOTE_REPO)/$(IMAGE_NAME)
-	docker push $(REMOTE_REPO)/$(IMAGE_NAME)
+> docker tag $(IMAGE_NAME) $(REMOTE_REPO)/$(IMAGE_NAME)
+> docker push $(REMOTE_REPO)/$(IMAGE_NAME)
 else
-	@echo "REMOTE_REPO not defined, not pushing to a remote repo."
+> @echo "REMOTE_REPO not defined, not pushing to a remote repo."
 endif
 
 .PHONY: clean
 clean:
-	docker rmi $(IMAGE_NAME)
+> docker rmi $(IMAGE_NAME)
 ifdef REMOTE_REPO
-	docker rmi $(REMOTE_REPO)/$(IMAGE_NAME)
+> docker rmi $(REMOTE_REPO)/$(IMAGE_NAME)
 else
-	@echo "REMOTE_REPO not defined, not removing from remote repo."
+> @echo "REMOTE_REPO not defined, not removing from remote repo."
 endif
 
 .PHONY: run
-run:
-	docker run --rm -i -t -p "8080:8080" $(IMAGE_NAME)
+run: ## Launch the docker image
+> docker run --rm -i -t -p "8080:8080" $(IMAGE_NAME)
 
 .PHONY: shell
-shell:
-	docker run --rm -i -t -p "8080:8080" --entrypoint /bin/bash $(IMAGE_NAME)
+shell: ## Launch an interactive shell inside the docker image.
+shell: build
+> docker run --rm -i -t -p "8080:8080" --entrypoint /bin/bash --mount type=tmpfs,destination=/tmp $(IMAGE_NAME)