allow to run as another user as root

Makefile

@@ -4,6 +4,9 @@ REPO  ?= dorowu/ubuntu-desktop-lxde-vnc
 TAG   ?= latest
 IMAGE ?= ubuntu:18.04
 LOCALBUILD ?= tw
+HTTP_PASSWORD ?= 123456
+CUSTOM_USER ?= ubuntu
+PASSWORD ?= ubuntu
 
 build:
 	docker build -t $(REPO):$(TAG) --build-arg localbuild=$(LOCALBUILD) --build-arg image=$(IMAGE) .
@@ -12,7 +15,9 @@ run:
 	docker run --rm \
 		-p 6080:80 -p 6081:443 \
 		-v ${PWD}:/src:ro \
-		-e HTTP_PASSWORD=123456 \
+		-e HTTP_PASSWORD=$(HTTP_PASSWORD) \
+		-e USER=$(CUSTOM_USER) \
+		-e PASSWORD=$(PASSWORD) \
 		--name ubuntu-desktop-lxde-test \
 		$(REPO):$(TAG)