Project 3: Write a MakeFile For Two-Tier-Flask-App

In this blog, I'll guide you through understanding and writing a Makefile that uses Docker Compose to build, run, and manage a two tier flask app across multiple operating systems. If you’re working on a project with Docker and need an easy way to streamline commands, this Makefile will come in handy.

Overview of the Makefile

A Makefile is a simple file that contains a set of instructions or rules for automating repetitive tasks. This specific Makefile is designed to manage a Dockerized service, with different commands tailored to run on Linux, macOS, and Windows. It provides four main functionalities:

1. Build the Docker image.

2. Run the service in the background.

3. Stop the service.

4. Clean up Docker resources.

Now, let's break down the Makefile and see how it works.

---

1. Determine the Operating System

OS := $(shell uname)

• $(shell uname): This command is used to detect the operating system by running the uname command.

  • On Linux, uname returns Linux.

  • On macOS, it returns Darwin.

  • On Windows, uname is not available, but the Makefile uses Windows_NT to handle Windows systems.

This OS detection allows the Makefile to adjust commands based on which platform it is being executed on.

---

2. Define Docker Compose Command

DOCKER_COMPOSE := docker compose

• This defines a variable DOCKER_COMPOSE which holds the command docker compose.

• This is used later in the script to run Docker Compose commands without repeating the full docker compose command every time.

---

3. Define the Docker Service Name

SERVICE_NAME := web

SERVICE_NAME is set to web, which is a placeholder for the actual name of the Docker service you are working with. In Docker Compose, services are defined in the docker-compose.yml file.

4. Build the Docker Image

build:

ifeq ($(OS),Linux)

@echo "Building for Linux"

$(DOCKER_COMPOSE) build

endif

ifeq ($(OS),Darwin)

@echo "Building for macOS"

$(DOCKER_COMPOSE) build

endif

ifeq ($(OS),Windows_NT)

@echo "Building for Windows"

# Add Windows-specific build commands if you wish

endif

This section defines the build target, which builds the Docker image using Docker Compose. It does this differently depending on the detected OS:

• Linux: If the OS is Linux, the script prints Building for Linux and runs docker compose build.

• macOS: If the OS is macOS, it prints Building for macOS and runs docker compose build.

• Windows: If it detects Windows_NT (for Windows), it prints Building for Windows. You can add Windows-specific build commands here.

5. Run the Service

run:

ifeq ($(OS),Linux)

@echo "Running for Linux"

$(DOCKER_COMPOSE) up -d

endif

ifeq ($(OS),Darwin)

@echo "Running for macOS"

$(DOCKER_COMPOSE) up -d

endif

ifeq ($(OS),Windows_NT)

@echo "Running for Windows"

# Add Windows-specific run commands if you wish

endif

The run target starts the Docker service defined in the docker-compose.yml file. Like the build section, it adjusts the commands depending on the OS:

• Linux: Runs docker compose up -d, which starts the Docker containers in the background.

• macOS: Same as Linux, running the service in the background.

• Windows: You can add custom run commands for Windows if needed.

6. Stop the Service

stop:

$(DOCKER_COMPOSE) down

The stop target stops and removes all running containers for the service. This target is the same for all operating systems, as the docker compose down command works across platforms.

7. Clean Up Docker Resources

The clean target first runs the stop target (i.e., stops the containers) and then removes any remaining containers and resources:

• $(DOCKER_COMPOSE) rm -f: Removes all stopped containers for the service.

• 'docker system prune -f': Cleans up any dangling Docker images, networks, volumes, and containers that are no longer in use.

This ensures that you’re left with a clean Docker environment.

8. How to Use the Makefile

You can use this Makefile to simplify your Docker workflows. To run the tasks:

1. Build the Docker image:

   make build

2. Run the Docker service:

   make run

3. Stop the Docker service:

   make stop

4. Clean up Docker resources:

   make clean

The 'make' command automatically detects the correct task based on the OS you are running on.

Conclusion

This Makefile helps streamline Docker-related tasks across different operating systems. It detects the OS and runs appropriate Docker Compose commands, making your workflow more efficient. Whether you're using Linux, macOS, or Windows, this Makefile allows you to quickly build, run, stop, and clean up your Docker services with just a few commands.

By using a Makefile, you reduce manual errors and improve the efficiency of repetitive tasks, making it easier to manage Dockerized services in a cross-platform environment.

You can access the MAKEFILE and two tier flask app from here:

https://github.com/huzefaweb/Makefile_for_two_tier_flask_app