Executing a command inside docker shows wrong $PATH

Question

I am trying to run a bash command inside docker from host:

$ docker exec -it -u weiss apollo_dev /bin/bash -c "rosbag"

/bin/bash: rosbag: command not found

So I tried:

$ docker exec -it -u weiss apollo_dev /bin/bash -c "echo \$PATH"

/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

But when I run docker interactively:

$ docker exec -it -u weiss apollo_dev /bin/bash
weiss@docker$ echo $PATH

/usr/local/cuda-8.0/bin:/home/tmp/ros/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

Any reason why I am getting different results for $PATH?

Answer 1

This path is most likely changed in your .bashrc file, and this file is not loaded when the shell is non interactive (see https://www.gnu.org/software/bash/manual/bash.html#Bash-Startup-Files)

So /bin/bash will load it, /bin/bash -c will not

Answer 2

Here you are getting de $PATH of your Host. Before you run the container the variable is replace for the host's $PATH.

$ docker exec -it -u weiss apollo_dev /bin/bash -c "echo \$PATH"

You need to pass the command without replace the variable, so when run the command in the container just invoke the $PATH variable.

$ docker exec -it -u weiss apollo_dev /bin/bash -c 'echo \$PATH'

Te 'apostrophe' is the key. Bye