Installing authorized_keys file under custom user for Ubuntu AWS - amazon-web-services

Question

I'm trying to setup an ubuntu server and login with a non-default user. I've used cloud-config with the user data to setup an initial user, and packer to provision the server:
system_info:
default_user:
name: my_user
shell: /bin/bash
home: /home/my_user
sudo: ['ALL=(ALL) NOPASSWD:ALL']
Packer logs in and provisions the server as my_user, but when I launch an instance from the AMI, AWS installs the authorized_keys files under /home/ubuntu/.ssh/
Packer config:
{
"variables": {
"aws_profile": ""
},
"builders": [{
"type": "amazon-ebs",
"profile": "{{user `aws_profile`}}",
"region": "eu-west-1",
"instance_type": "c5.large",
"source_ami_filter": {
"most_recent": true,
"owners": ["099720109477"],
"filters": {
"name": "*ubuntu-xenial-16.04-amd64-server-*",
"virtualization-type": "hvm",
"root-device-type": "ebs"
}
},
"ami_name": "my_ami_{{timestamp}}",
"ssh_username": "my_user",
"user_data_file": "cloud-config"
}],
"provisioners": [{
"type": "shell",
"pause_before": "10s",
"inline": [
"echo 'run some commands'"
]}
]
}
Once the server has launched, both ubuntu and my_user users exist in /etc/passwd:
my_user:1000:1002:Ubuntu:/home/my_user:/bin/bash
ubuntu:x:1001:1003:Ubuntu:/home/ubuntu:/bin/bash
At what point does the ubuntu user get created, and is there a way to install the authorized_keys file under /home/my_user/.ssh at launch instead of ubuntu?

Answer 1

To persist the default user when using the AMI to launch new EC2 instances from it you have to change the value is /etc/cloud/cloud.cfg and update this part:
system_info:
default_user:
# Update this!
name: ubuntu

Answer 2

You can add your public keys when you create the user using cloud-init. Here is how you do it.
users:
- name: <username>
groups: [ wheel ]
sudo: [ "ALL=(ALL) NOPASSWD:ALL" ]
shell: /bin/bash
ssh-authorized-keys:
- ssh-rsa AAAAB3Nz<your public key>...
Addding additional SSH user account with cloud-init