Docker command works in terminal but not script

Question

After following instructions to setup a blockchain system, my colleague moved everything into a script since it needs to be run multiple times.

However as a script it fails on the following line:

docker exec -it cli bash

When entering it into a terminal use user and path change to root@someaddress which I assume is the new docker container. Then -it cli bash should create a new bash environment to run the rest of the commands.

Is there any reason this doesn't work as a shell script?

Answer 1

Bash command in docker

Welcome to Docker ;-) The command docker run -it cli bash starts the Docker image cli and than runs the bash command as login shell inside the container. This is way you get the root@someaddress prompt. So everything is as expected.

If you want to execute a command inside the container (and exit the container after that), use this:

docker run -it cli bash -c "echo hello from \$host; ls -la /"

Beware, quoting is important after the -c switch. If you need more information on the command_string checkout the bash manpage.

Run command(s) in container

There are many ways to get bash commands executed inside the container:

# mount the script into the container with -v
script=$(readlink -f myscript.sh)
docker run -it -v $script:$script cli bash $script

# use bash array to pass the commands into the container
cmd_list=()
cmd_list+=(echo cmd1)
cmd_list+=(echo cmd2)
cmd_list+=(echo done)
docker run -it cli bash -c "${cmd_list[*]}"

# google: bash here script