add restart policy to docker compose, add sample dockerfile for demoing features

06-building-container-images/Makefile

@@ -12,4 +12,45 @@ compose-up-build:
 
 .PHONY: compose-down
 compose-down:
-	docker compose down
+	docker compose down
+
+.PHONY: build-sample
+build-sample:
+	docker build -t sample -f Dockerfile.sample .
+
+define ENTRYPOINT_CMD_DESCRIPTION
+##############################
+
+See Dockerfile.sample for image definition.
+
+This series of docker run commands is meant
+to help you understand the interaction between
+CMD and ENTRYPOINT.
+
+The image has the following:
+
+ ENTRYPOINT [ "echo", "Hey Team 👋 (entrypoint)" ]
+ CMD [ "+ (cmd)" ]
+
+##############################
+endef
+export ENTRYPOINT_CMD_DESCRIPTION
+
+.PHONY: run-sample-entrypoint-cmd
+run-sample-entrypoint-cmd: build-sample
+	@echo "$$ENTRYPOINT_CMD_DESCRIPTION"
+
+	@echo "Run with no arguments:"
+	docker run sample
+
+	@echo "##############################"
+	@echo "Run with argument (CMD is ignored):"
+	docker run sample "+ (argument)"
+
+	@echo "##############################"
+	@echo "Overriden entrypoint with no arguments (CMD is ignored):"
+	docker run --entrypoint echo sample
+
+	@echo "##############################"
+	@echo "Overriden entrypoint with arguments (CMD is ignored):"
+	docker run --entrypoint echo sample "Hey Team 👋 (Overriden entrypoint + arguments)"