How To Install Docker Compose On Centos 7

Before diving into the installation process, it’s essential to ensure that your system meets the necessary prerequisites. Here are the steps you need to follow:

CentOS 7 Operating System: Ensure that you have a running instance of CentOS 7.
Sudo privileges: You must have access to a user account with sudo privileges to execute administrative commands.
Docker: Docker must be installed on your CentOS 7 system. If not already installed, you can find instructions on the official Docker documentation.
Curl: The curl tool is used to download files from the internet and should be installed on your system.

Checking for Docker Installation

To verify if Docker is installed on your CentOS 7 system, run the following command:

docker --version

If Docker is installed, you will see the version number in the output. If not, you’ll need to install Docker first.

Step-by-Step Guide to Install Docker Compose

Step 1: Update the System Packages

It’s always a good practice to update your system packages before installing new software. Use the following command to update your system:

sudo yum update -y

Step 2: Downloading Docker Compose

Docker Compose can be downloaded from its official GitHub repository. To get the latest stable release, use the curl command as follows:

sudo curl -L "https://github.com/docker/compose/releases/download/1.29.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose

Replace 1.29.2 with the latest release available at the time of your installation.

Step 3: Setting Up Execute Permissions

After downloading, you need to apply executable permissions to the binary file:

sudo chmod +x /usr/local/bin/docker-compose

Step 4: Verifying Docker Compose Installation

To confirm that Docker Compose has been successfully installed, check its version by running:

docker-compose --version

This command should return the version of Docker Compose that was installed.

Configuring Docker Compose

Creating a Docker Compose File

Docker Compose uses a YAML file to define multi-container applications. Here’s an example of how to create a simple docker-compose.yml file:

version: '3'
services:
  web:
    image: nginx
    ports:
      - "80:80"

This configuration will set up a single service called “web” using the nginx image and map port 80 on the host to port 80 in the container.

Running Docker Compose

To start the application defined in your docker-compose.yml file, navigate to the directory containing the file and run:

docker-compose up

To run Docker Compose in detached mode (in the background), use the -d flag:

docker-compose up -d

Troubleshooting Common Issues

Permission Denied Error

If you encounter a permission denied error when trying to execute Docker Compose, it may be due to incorrect permissions. Ensure that the docker-compose binary has the correct permissions by reapplying them:

sudo chmod +x /usr/local/bin/docker-compose

Version Mismatch Error

A version mismatch error occurs when the docker-compose.yml file specifies a version that is not compatible with the installed Docker Compose. Make sure that the version specified at the top of your YAML file matches the capabilities of your Docker Compose version.

Frequently Asked Questions

Can I install Docker Compose without root or sudo access?

No, installing Docker Compose typically requires root or sudo access to place the binary in /usr/local/bin and apply the necessary permissions.

How do I upgrade Docker Compose?

To upgrade Docker Compose, simply repeat the download step with the newer version’s URL and apply the executable permissions again.

What is the difference between Docker and Docker Compose?

Docker is a platform for developing, shipping, and running applications inside containers. Docker Compose is a tool for defining and running multi-container Docker applications.

Is Docker Compose suitable for production environments?

While Docker Compose is primarily designed for development and testing workflows, it can be used in production with careful planning and understanding of its limitations.

References

Docker Compose Official Documentation: https://docs.docker.com/compose/
Docker Compose GitHub Releases: https://github.com/docker/compose/releases
CentOS Official Documentation: https://www.centos.org/docs/