Chapter 10. Docker and security
This chapter covers
- The level of security Docker offers out of the box
- What Docker has done to help make it more secure
- What other parties are doing about it
- What other steps can be taken to ameliorate security concerns
- How to manage users in a multi-tenant environment
As Docker makes clear in its documentation, access to the Docker API implies access to root privileges, which is why Docker must often be run with sudo, or the user must be added to a user group (which might be called docker or dockerroot) that allows access to the Docker API.
In this chapter we’re going to look at the issue of security in Docker.
You may be wondering what sort of damage a user can do if they can run Docker. As a simple example, this command (don’t run it!) would delete all the binaries in /sbin on your host machine (if you took out the bogus --donotrunme flag):
It’s worth pointing out that this is true even if you’re a non-root user. This command will show you the contents of the secure shadow password file from the host system: