add mandatory variables

Makefile

@@ -12,7 +12,19 @@ include make-deploy/helm.mk
 self-update:
 	@- git submodule update --remote
 
-deploy: build test upload pre-deploy pre-local pull start post-local post-deploy reload
+deploy: mandatory build test upload pre-deploy pre-local pull start post-local post-deploy reload
+
+mandatory:
+	@- echo "\n### mandatory check"
+ifndef MANDATORY-$(DEPLOY_TYPE)
+	$(error MANDATORY-$(DEPLOY_TYPE) is not defined)
+endif
+	@ $(foreach var,$(MANDATORY), \
+		if test -z "${$(var)}"; then \
+			echo "Missing mandatory variable: $(var)"; \
+			exit 1; \
+                fi; \
+	)
 
 build:
 ifneq (,$(wildcard build.sh))

docker.mk

@@ -1,3 +1,4 @@
+MANDATORY-compose = DEPLOY_HOSTS DEPLOY_TYPE TAG
 pull-compose:
 	@- echo "\n### pulling image(s)"
 	@- $(foreach host,$(DEPLOY_HOSTS), \