How to know if a docker container is running in privileged mode

Question

Would like to know via bash script, if current running container was started in --privileged mode from inside the container (not from the host machine).

For now I'm stuck with passing an env var with the flag but is not an ideal solution.

Answer 1

From the docker host

Use the docker inspect command:

docker inspect --format='{{.HostConfig.Privileged}}' <container id> 

And within a bash script you could have a test:

if [[ $(docker inspect --format='{{.HostConfig.Privileged}}' <container id>) == "false" ]]; then     echo not privileged else     echo privileged fi 

From inside the container itself

You have to try to run a command that requires the --privileged flag and see if it fails

For instance ip link add dummy0 type dummy is a command which requires the --privileged flag to be successful:

$ docker run --rm -it ubuntu ip link add dummy0 type dummy RTNETLINK answers: Operation not permitted 

while

$ docker run --rm -it --privileged ubuntu ip link add dummy0 type dummy 

runs fine.

In a bash script you could do something similar to this:

ip link add dummy0 type dummy >/dev/null if [[ $? -eq 0 ]]; then     PRIVILEGED=true     # clean the dummy0 link     ip link delete dummy0 >/dev/null else     PRIVILEGED=false fi