Root password inside a Docker container

Question

I'm using a Docker image which was built using the USER command to use a non-root user called dev. Inside a container, I'm "dev", but I want to edit the /etc/hosts file.

So I need to be root. I'm trying the su command, but I'm asked to enter the root password.

What's the default root user's password inside a Docker container?

Answer 1

I'd suggest a better solution is to give the --add-host NAME:IP argument to docker run when starting the container. That will update the /etc/hosts/ file without any need to become root.

Otherwise, you can override the the USER setting by giving the -u USER flag to docker run. I would advise against this however, as you shouldn't really be changing things in a running container. Instead, make your changes in a Dockerfile and build a new image.

Answer 2

try the following command to get the root access

$ sudo -i 

Answer 3

docker exec -u 0 -it containername bash

Answer 4

When you start the container, you will be root but you won't know what root's pw is. To set it to something you know simply use "passwd root". Snapshot/commit the container to save your actions.

Answer 5

Get a shell of your running container and change the root password:

docker exec -it <MyContainer> bash

root@MyContainer:/# passwd
Enter new UNIX password:
Retype new UNIX password:

Answer 6

You can use the USER root command in your Dockerfile.