Manage local users

In this tutorial we will show how to use CFEngine to manage users, add them to groups, setup their home directory and copy ssh-keys to their ~/.ssh directory as part of creating the user.

1. Create some files and groups that we will use

Create the files id_rsa and id_rsa.pub in /tmp.

# touch /tmp/id_rsa /tmp/id_rsa.pub

Create user group security and webadmin.

# sudo groupadd security 
# sudo groupadd webadmin

1. Create CFEngine policy called users.cf

Create a file /tmp/users.cf with the following content:

body common control
{
  inputs => { "$(sys.libdir)/stdlib.cf" };
}

bundle agent main
{
  vars:
  "users" slist => { "adam", "eva" };
  users:
    "$(users)"
    policy => "present",
    home_dir => "/home/$(users)",
    group_primary => "users",
    groups_secondary => { "security", "webadmin" },
    shell => "/bin/bash/",
    home_bundle => setup_home_dir("$(users)");
}

bundle agent setup_home_dir(user)
{
  vars:
    "keys" slist => { "id_rsa", "id_rsa.pub" };
  files:
    "/home/$(user)/." create => "true";
    "/home/$(user)/.ssh/." create => "true";
    "/home/$(user)/.ssh/$(keys)" copy_from => local_cp("/tmp/$(keys)");
}

1. Test it out, and verify the result

Run CFEngine:

# /var/cfengine/bin/cf-agent -fK /tmp/users.cf

Verify the result: Have users have been created?

# grep -P "adam|eva" /etc/passwd

Congratulations! You should now see the users adam and eva listed.

Verify the result: Have users home directory have been created?

# ls /home | grep -P "adam|eva"

Congratulations! You should now see adam and eva listed.

Verify the result: Have users have been added to the correct groups?

# grep -P "adam|eva" /etc/group

Congratulations! You should now see adam and eva added to the groups security and webadmin. NOTE: CFEngine's users type promise will not create groups, so you must make sure the groups exists.

Verify the result: Have ssh-keys have been copied from /tmp to user’s ~/.ssh directory?

# ls /home/adam/.ssh /home/eva/.ssh

Congratulations! You should now see the files id_rsa and id_rsa.pub.

Ps. If you would like play around with the policy, delete the users after each run with the command

# deluser -r username

Mission accomplished!