How to install PHP composer inside a docker container

How to Install PHP Composer Inside a Docker Container

If you're working on a Laravel project using Docker, you might encounter the need to have PHP Composer inside your Docker container. This becomes essential when working with database migration, as Laravel requires Composer to run the composer dump-autoload command. However, installing Composer inside the Docker container can be a bit tricky. In this guide, I'll show you how to overcome the common error "executable file not found in $PATH" and successfully install PHP Composer.

The Problem

Let's set the context. You have a Dockerfile that installs PHP and other necessary dependencies. You've tried using the following command to install Composer inside the container:

RUN curl -sS https://getcomposer.org/installer | php -- \
--install-dir=/usr/bin --filename=composer

However, when you run docker-compose up and then docker-compose exec app composer dump-autoload, you encounter the following error:

rpc error: code = 13 desc = invalid header field value "oci runtime error: exec failed: container_linux.go:247: starting container process caused \"exec: \\\"composer\\\": executable file not found in $PATH\"\n"

The Solution

To resolve this issue, you need to modify your Dockerfile and update the PATH variable to include the location where Composer is installed.

1. Open your Dockerfile and add the following line after installing Composer:

ENV PATH="/usr/bin/vendor/bin:${PATH}"

This line ensures that the Composer binary is accessible in the container's PATH.

1. Save the Dockerfile and rebuild your Docker image. Run the following command in your terminal:

docker-compose build

This command will rebuild your Docker image with the changes made to the Dockerfile.

1. Now, when you run docker-compose up and subsequently use docker-compose exec app composer dump-autoload, you should no longer encounter the "executable file not found in $PATH" error.

Engage with the Community!

That's it! You've successfully installed PHP Composer inside your Docker container and resolved the error. You can now enjoy a seamless development environment for your Laravel project.

If you found this guide helpful or have any other questions or issues, feel free to reach out to the community. Share your thoughts, suggestions, and experiences in the comments below. Don't forget to check out the GitHub repository for further details on the Docker Compose configuration and other helpful resources.

Happy coding! 👨‍💻🚀