Docker Linux – Kill Command Not Found in Docker Container

It should be actively discouraged to set the DEBIAN_FRONTEND to noninteractive via ENV. The reason is that the environment variable persists after the build, e.g. when you run docker exec -it ... bash. The setting would not make sense here.

There are two other possible ways:

1. Set it via ARG as this only is available during build:

   ARG DEBIAN_FRONTEND=noninteractive
   RUN apt-get -qq install {your-package}
   

2. Set it on-the-fly when required.

   RUN apt-get update && \
       DEBIAN_FRONTEND=noninteractive apt-get -qq install {your-package}
   

Use docker volumes, to store files in host system. For example, you can run your image with these options:

docker run --name mylamp -v /docker/site:/var/www -p 80:80 me/mylamp:tag

Now, your mylamp image mounts internal /var/www directory to external /docker/site directory, so you can use SSH/SFTP/FTP to upload files to /docker/site directory on your host system, and it will be visible inside docker image in /var/www directory.