Monday 29 April 2013

Chef Experiments - Create Users



The objective here is to create  a users cookbook with data bags

Create the data bag

knife data bag create user_config

Create the user json file

data_bags/users/usr_sri.json 

"id": "sri",
{

    "comment": "Sriram Rajan",

    "uid": 2000,

    "gid": 0,

    "home":"/home/sri",

    "shell":"/bin/bash",

    "pubkey":"<replace with the SSH public key"

}


Import the file

knife data bag from file users_config usr_sri.json


Create a key for the encrypted data bag

openssl rand -base64 512 > data_bags/users/enckey


Create the encrypted data bag

knife data bag create --secret-file  data_bags/users/enckey password_config pwdlist



Edit the data bag

knife data bag edit --secret-file  data_bags/users/enckey password_config pwdlist


"id": "pwdlist",
{
"sri": "Replace with SHA password string"
}


At this point you should have a data bag with users and encrypted data bag with passwords. Now we move to the cookbook

Create the cookbook

knife cookbook create user_config

Recipe looks like this. We add the user and also ensure the .ssh directory is created and populated with the public keys. The password will be pulled from the encrypted bag.


decrypted = Chef::EncryptedDataBagItem.load("password_config", "pwdlist")
search(:user_config, "*:*").each do |user_data|
    user user_data['id'] do
        comment user_data['comment']
        uid user_data['uid']
        gid user_data['gid']
        home user_data['home']
        shell user_data['shell']
        manage_home true
        password decrypted[user_data['id']
        action:create
    end
  
    ssh_dir = user_data['home'] + "/.ssh"
    directory ssh_dir do
        owner user_data['uid']
        group user_data['gid']
        mode "0700"
    end

    template "#{ssh_dir}/authorized_keys" do
        owner user_data['uid']
        group user_data['gid']
        mode "0600"
        variables(
             :ssh_keys => user_data['pubkey']
             )
        source "authorized_keys.erb"
    end
end

The template file

base_users/templates/default/authorized_keys.erb 

<% Array(@ssh_keys).each do |key| %>

<%= key %>

<% end %>



Finishing up
knife cookbook upload user_config

Ensure the secret key for the encrypted data bag is also sent to the node and stored under  /etc/chef/encrypted_data_bag_secret. You can bootstrap this file into the node build. See http://docs.opscode.com/essentials_data_bags_encrypt.html

Then add the recipe to a role or node run list and run the chef-client to test.

1 comment:

  1. Thanks for sharing !

    At line :
    knife data bag from file users_config usr_sri.json

    It should be read:
    knife data bag from file user_config usr_sri.json

    Isn't usr_sri.json a malformed JSON file btw ?

    ReplyDelete