Ubuntu 20.04 Cloud-Init Example to Create a User That Can Use sudo

Use the steps below and example config to create a cloud-init file that creates a user, sets their password, and enables SSH access. The Cloud Config documentation has some examples, but they don’t actually work for being able to ssh into a server and run commands via sudo

First, create a password hash with mkpasswd command:

$ mkpasswd -m sha-512
Password:  
$6$nq4v1BtHB8bg$Oc2TouXN1KZu7F406ELRUATiwXwyhC4YhkeSRD2z/I.a8tTnOokDeXt3K4mY8tHgW6n0l/S8EU0O7wIzo.7iw1

Make note of the output string. You need to enter it exactly in the passwd line of your cloud-init config.

This is the minimal configuration to create a user using cloud-init:

users:
  - name: brandon
    groups: [ sudo ]
    shell: /bin/bash
    lock_passwd: false
    passwd: "$6$nq4v1BtHB8bg$Oc2TouXN1KZu7F406ELRUATiwXwyhC4YhkeSRD2z/I.a8tTnOokDeXt3K4mY8tHgW6n0l/S8EU0O7wIzo.7iw1"
    ssh-authorized-keys:
    - ssh-ed25519 AAAAC3NzaC1lZDI1zzzBBBGGGg3BZFFzTexMPpOdq34a6OlzycjkPhsh4Qg2tSWZyXZ my-key-name

A few things that are noteworthy:

  • The string in the passwd field is enclosed in quotes
  • lock_passwd: false is required to use sudo. Otherwise, the system user account created will have a disabled password and will be unable to use sudo. You’ll just continually be asked for a password, even if you enter it correctly.
  • I prefer the method of adding the user to the sudo group to grant access to sudo. There are other ways to make that work as well, but I feel like this is the cleanest.
  • Adding any users, will prevent the default ubuntu user from being created.
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