User Management

Document Control

TODO:

Overall structure.
Initial draft complete
Add update_password on_create with vault stored password
Generate random password, use filters and retrieve it locally to file.
Testing
Ready

User Story: Linux User Management

As a: UNIX and Linux system administrator

I want to:

add users and groups to the system from a list
configure defined or random passwords, optionally store them in a vault
configure SSH key access

So that: I can automate my OS post-deployment and user management steps.

Managing user accounts

Group and User Creation

Creating the user and group devops for use with ansible

The user will be added to the sudoers file, and set up with an ssh key.

Creating the devops user, group and sudoers entry

group

- name: groups are created
  group:
    name: devops
  become: true

user

- name: User, shell and secondary groups setup
  user:
    name: devops
    shell: /bin/bash
    comment: DevOps user used by ansible
    groups: devops
    append: true
  become: true

password

- name: Update user password
  user:
    name: devops
    password: "{{ "$ecure_Passw0rd" | password_hash('sha512') }}"
    update_password: always
  become: true

ssh

- name: Set authorized key taken from file
  authorized_key:
    user: devops
    key: "paste_your_key_here"
    state: present
  become: true

sudo

- name: sudo package is installed
  package:
    name: sudo
    state: present
  become: true

sudoers

- name: add defined groups to sudoers
  template:
    src: sudoers.j2
    dest: "/etc/sudoers.d/devops"
    validate: 'visudo -cf %s'
    mode: "0440"
  when: item.sudo
  become: true

Parametrization

Creating defined users and groups

The user will be added to the sudoers file, and set up with an ssh key. The list of users and groups is defined in a variables file.

Using a dictionary to create multiple users and groups

Example command with shell, yaml and output

vars

users_groups:
  - wheel
  - docker

users_username:
  - name: devops
    sudo: true
    shell: /usr/bin/bash
    groups: wheel
    ssh_key: "{{ lookup('file', lookup('env','HOME') + '/.ssh/id_rsa.pub') }}"
    comment: 'Ansible user'

  - name: docker
    sudo: true
    shell: /usr/bin/zsh
    groups: docker
    ssh_key: "{{ lookup('file', lookup('env','HOME') + '/.ssh/id_rsa.pub') }}"
    comment: 'Regular user for use with docker'

group

- name: groups are created
  group:
    name: "{{ item }}"
  loop: "{{ users_groups }}"

user

- name: User, shell and secondary groups setup
  user:
    name: "{{ item.name }}"
    shell: "{{ item.shell | default('/bin/bash') }}"
    comment: "{{ item.comment }}"
    groups: "{{ item.groups | default(omit) }}"
    append: true
  become: true

ssh

- name: Set authorized key taken from file
  authorized_key:
    user: "{{ item.name }}"
    key: "{{ item.ssh_key }}"
    state: present
  when: item.ssh_key is defined
  become: true

sudoers

- name: add defined groups to sudoers
  template:
    src: sudoers.j2
    dest: "/etc/sudoers.d/{{ item.name }}"
    validate: 'visudo -cf %s'
    mode: "0440"
  when: item.sudo
  become: true

Generating a random password

Using lookup plugins and hashing filters to set a random password

password

- name: Set user password to random and store it in a file
  vars:
    password: "{{ lookup('password', 'credentials/mypass'
      + ' length=9 chars=ascii_letters,digits,hexdigits,punctuation') }}"
  user:
    name: devops
    password: "{{ password | password_hash('sha512') }}"
    update_password: always
  become: true

Notice how the password variable is used to simplify the playbook

Creating and using a role

Use a role to setup the devops user

You can create a role under roles/users or download crivetimihai.users using ansible-galaxy. Create a playbook called users-playbook.yml that defines / overrides the default variables of the role.

Using the role in a playbook

users-playbook.yml

---
- name: Install users on localhost
  hosts:
    - localhost
  connection: local

  tasks:
    - name: users is configured
      import_role:
        name: crivetimihai.users
      vars:
        users_groups:
          - wheel

        users_username:
          - name: devops
            sudo: true
            shell: /usr/bin/bash
            groups: wheel
            ssh_key: "{{ lookup('file', lookup('env','HOME') \
              + '/.ssh/id_rsa.pub') }}"
            comment: 'Created by ansible'
      tags: users

Run ansible-playbook

# Install the role
ansible-galaxy install crivetimihai.users

# Run the playbook
ansible-playbook users-playbook.yml

Last update: 2020-02-03