How to install Composer with docker exec

I'm trying to install composer on docker container. I have a container laravel55 and I'm gonna to install composer insite it.

docker exec laravel55 curl --silent --show-error | php #result Composer (version 1.6.5) successfully installed to: /root/docker- images/docker-php7-apache2/composer.phar Use it: php composer.phar 

Aftar installation, I'm trying to using composer but it doesn't work:

 docker exec -w /var/www/html laravel55 php composer.phar install #result Could not open input file: composer.phar 

It seems that Composer had not installed! How can I install composer on a docker container?

2 Answers

Well with your command you're actually installing composer.phar locally on your host, you just execute the curl command inside the container. The part behind the pipe symbol | is not executed in your docker container but on your host. In your second command you switch your working directory to /var/www/html where you apparently expect the composer.phar but not in the first command.

So to make the whole command run in the container, you can try the following:

docker-compose exec -w /var/www/html laravel55 \ sh -c "curl --silent --show-error | php" 

You could use official composer image from dockerhub and mount on it a volume from your app container

i.e

docker run -td --name my_app --volume /var/www myprivateregistry/myapp docker run --rm --interactive --volumes-from my_app --volume /tmp:/tmp --workdir /var/www composer install