Docker is one of the most popular containerization technologies owing to its ease of use and flexibility.
Many cloud platforms support Docker, and you’re able to run docker containers in many environments.
One of Dockers selling points is its functionality for working with multiple containers quickly.
This makes Docker suitable for building both monolithic applications and microservices.
Docker Compose is the tool Docker uses to achieve cross-container interaction and orchestration.
What Is Docker Compose?
Docker Compose is a simple container orchestration tool built on the Docker engine.
It lets you work with multiple Docker containers.
There aremany reasons to use Docker for virtualization, from its scalability to its built-in version control.
you might use Docker Compose to build full-stack apps with multiple architectural patterns.
Docker Compose is an agnostic tool that powers many containerized microservice applications.
With Docker Compose, you still get to use a single host environment for your software.
But you avoid the hassles of multiple configurations that can compromise your apps security and productivity.
Docker Compose doesnt use Dockerfiles for builds.
Instead, youll use adocker-compose.yamlfile for your apps configuration tweaks.
it’s possible for you to configure many different build controls in the YAML file.
These include port mapping, environment variables, volumes and networks, and services.
Check Docker Compose Is Installed
Thedocker-composeprogram runs on the Docker engine.
Docker Compose is part of a macOS or Windows installation of Docker CLI and Docker GUI.
The Docker engine is a dependency for Docker Compose.
Youll need to ensure that you have Docker installed before attempting to install Docker Compose.
The Docker Compose YAML File
Docker Compose uses a.yamlfile for build specifications.
Youll use thedocker-composefile to define your apps' services, networks, and volume configurations for your apps build.
Afterwriting the Dockerfilefor your app, create a docker-compose file in the root directory of your working directory.
In theserviceskey, you’re free to define the container configurations.
Thewebkey defines the service name.
you’re free to specify additional fields for your database and services in thedocker-composefile.
It will build docker files in the root directory to run on port8080with a Redis database image andenvironment variablesdeclared.
Docker Compose Commands
you’re free to use many other commands withdocker-composefor your container orchestration-related operations.
Thebuildcommand builds or rebuilds the images in thedocker-composeYAML file and creates the containers for your service.
Theruncommand starts up your services as specified in thedocker-composefile by creating the containers from the Docker images.
Theimagescommand lets you view a list of the images built from your docker-compose file.
Theupcommand is the combination of thebuildandruncommands.
This command builds and runs the Docker images and starts the containers.
you could use thepscommand to list all containers in thedocker-composefile.
Thedowncommand stops and cleans up containers and images associated with thedocker-composefile.
Youll find thestopcommand useful if you only want to stop all containers and services in yourdocker-composefile.
Docker Compose offers easier container management, so using Docker can be more productive than other competing technologies.
