This article explores the distinction between a stack file and a Compose file in the context of Docker.

Both files serve as configuration files in Docker, with stack files used in Docker Swarm and Compose files used for a single Docker engine.

The stack file, written in YAML format, defines one or more services and includes additional configuration parameters such as replicas, deploy, and roles.

Conversely, the Compose file, typically named docker-compose.yml, lacks these specific parameters.

The docker stack command interprets the stack file and can only be invoked from a Docker swarm manager, while the docker-compose up command creates and updates containers, networks, volumes, etc.

Docker-compose is more suitable for development purposes, as it facilitates image building, pulling, and updating, whereas Docker Stack is better suited for deployment purposes.

By examining their use cases, key differences, and features, this article aims to provide a comprehensive understanding of stack files and Compose files in Docker.

Stack vs Compose

The main difference between a stack file and a Compose file lies in their usage and purpose within Docker.

A stack file is specifically used in Docker Swarm for orchestration and scheduling of services. It is a YAML file that defines one or more services, similar to a docker-compose.yml file.

Stacks have additional configuration parameters like replicas, deploy, and roles that are not needed in docker-compose.

The docker stack command is used to interpret the stack file and can be invoked from a Docker swarm manager only.

On the other hand, a Compose file is used for defining and running multi-container Docker applications on a single Docker engine. It is better suited for development purposes.

The docker-compose up command is used to create/update containers, networks, volumes, etc.

Docker-compose can work interchangeably with Docker Stack if using version 3.x of the Compose file format.

Use Cases

Use cases for stack and Compose files vary depending on the specific requirements and goals of the Docker deployment.

Docker-compose is primarily used for development purposes, where it allows developers to define and run multi-container Docker applications on a single docker engine. It is especially useful for creating development environments that closely resemble production environments.

On the other hand, Docker Stack is better suited for deployment scenarios where the focus is on orchestrating and scheduling containers across a swarm cluster. It allows for the definition of services, networks, and volumes with additional configuration parameters such as replicas, deploy, and roles.

Docker Stack is particularly useful for deploying pre-built applications in a distributed environment.

Key Differences

Significant distinctions exist in terms of functionality and purpose between the configuration files used in Docker Swarm and those used in a single Docker engine.

The stack file, which is used in Docker Swarm, is a YAML file that defines one or more services and includes additional configuration parameters such as replicas, deploy, and roles.

On the other hand, the Compose file, used for a single Docker engine, is also a YAML file but is better suited for development purposes. It allows the definition and running of multi-container Docker applications on a single engine and includes features such as building, pulling, and updating images.

While Docker Stack is integrated into Docker Swarm and can only be invoked from a Docker swarm manager, Docker-compose is a separate tool that needs to be installed separately on Linux but is bundled with Docker on Windows.