[chef] Re: Re: Re: Re: Re: Creating authorized_keys for LDAP users.


Chronological Thread 
  • From: Douglas Garstang < >
  • To:
  • Subject: [chef] Re: Re: Re: Re: Re: Creating authorized_keys for LDAP users.
  • Date: Tue, 27 Jan 2015 08:31:36 -0800

I am using nscd. It's functionality, and how it is restarted, is wrapped up in the upstream LDAP cookbook.

Doug.


On Mon, Jan 26, 2015 at 7:10 PM, Lamont Granquist < " target="_blank"> > wrote:

Uli Drepper's response from 10 years ago is to run nscd:

https://bugzilla.redhat.com/show_bug.cgi?id=132608#c2

Not sure if a process starts before nscd if there's still a race there or not, but I think every time you hit the nss functions in glibc it checks the ncsd socket so that it would work.


On 1/26/15 3:52 PM, Noah Kantrowitz wrote:
Chef and Ohai use the Etc library in Ruby, which in turn uses the standard getpw* and getgr* calls. These are configured by nsswitch.conf. If you go look this up, you'll see that that file is only read once for a given process and there is no universal way to clear the config. Some libcs offer non-standard calls for it, but I doubt any of those are exposed to Ruby.

--Noah

On Jan 26, 2015, at 3:29 PM, Douglas Garstang < " target="_blank"> > wrote:

Sorry to have to repeat myself, but I can't use 'owner' and 'group' on resources. Even thought LDAP is configured, chef isn't able to see the users and groups.

David suggested I reload ohai. I had no idea this was necessary or required, but I tried it anyway. I put this at the end of my ldap cookbook.

ohai "reload_passwd" do
   plugin "etc"
end
log node['etc']['passwd']

What I am seeing, (I'm using vagrant), is that on the first chef run, the LDAP users are not in in the node structure. However, if I reprovision, (without making any changes), then the users ARE there.

In hindsight, isn't this just the typical node[] not being populated until after the chef run issue?

Doug.

On Mon, Jan 26, 2015 at 3:22 PM, Lamont Granquist < " target="_blank"> > wrote:
On 1/26/15 2:29 PM, Douglas Garstang wrote:
I'm having trouble setting up users authorized keys. A cookbook that runs earlier in the runlist sets up LDAP. However, due to reasons I don't understand, none of that user information is available during the chef run. I previously posted about this once before. As a result, I can't simply create files and directories and use 'owner' and 'group.

I came up with the below idea. I'm iterating over the ssh keys in a data bag and then for each user running a command as this user. That makes PAM do all the home directory setup for me. I create the ~/.ssh directory in a similar fashion, as the user. All works ok. However, I'm having an issue with adding the array of ssh_keys pulled from the data bag to the users authorized keys file.

include_recipe "slice-ldap"
bag = data_bag("ssh-keys")
for item in bag do
   user = data_bag_item('ssh-keys', item)
   user_name = user['id']
   ssh_keys = user['ssh_keys']
   execute "create_home_#{user_name}" do
     command "su - #{user_name} -c \"ls\""
     creates "/home/#{user_name}"
     notifies :run, "execute[create_ssh_dir_#{user_name}]", :immediately
   end
   execute "create_ssh_dir_#{user_name}" do
     command "su - #{user_name} -c \"mkdir /home/#{user_name}/.ssh\""
     notifies :run, "execute[install_public_rsa_#{user_name}]", :immediately
     creates "/home/#{user_name}/.ssh"
   end
   ssh_keys.each_with_index do |k, index|
     log "k = #{k}"
     execute "install_public_rsa_#{user_name}" do
       command "su - #{user_name} -c \"echo '#{k}' >> /home/#{user_name}/.ssh/authorized_keys\""
       action :nothing
     end
   end
end

However, I'm having an issue with adding the array of ssh_keys pulled from the data bag to the users authorized keys file. The loop at the end does this, but chef also gives me this warning:

==> default: [2015-01-26T22:23:47+00:00] WARN: Previous execute[install_public_rsa_doug]: /tmp/vagrant-chef-3/chef-solo-1/cookbooks/slice-ssh-keys/recipes/default.rb:38:in `block (2 levels) in from_file'
==> default: [2015-01-26T22:23:47+00:00] WARN: Current  execute[install_public_rsa_doug]: /tmp/vagrant-chef-3/chef-solo-1/cookbooks/slice-ssh-keys/recipes/default.rb:38:in `block (2 levels) in from_file'


Apart from the warning, only the last ssh keys is being added to the authorized_keys file. Even though I'm using echo and >>, the last one is not there. The log statement shows each key, so I know the loop is iterating over both. What gives?

Doug

Yeah the warning is trying to tell you the problem.  You're defining multiple resources called `execute[install_public_rsa_doug]` and the resource collection and the way notifies and subscribes is implemented requires unique names.  So you're getting resource cloning and you're only notifying one of those blocks.  You could add the index to then name and then subscribe to the previous resources:

   ssh_keys.each_with_index do |k, index|
     log "k = #{k}"
     execute "install_public_rsa_#{user_name}_#{index}" do
       command "su - #{user_name} -c \"echo '#{k}' >> /home/#{user_name}/.ssh/authorized_keys\""
       subscribes :run, "execute[#{create_ssh_dir_#{user_name}]"
       subscribes :run, "execute[#{create_home_#{user_name}]"
       action :nothing
     end
   end

You'll be way better off just doing this though:

file "/home/#{user_name}" do
   owner user_name
   group user_name  # or "users" or whatever
   mode "0600"
end

file "/home/#{user_name}/.ssh" do
   owner user_name
   group user_name
   mode "0600"
end

file "/home/#{user_name}/.ssh/authorized_keys" do
   owner user_name
   group user_name
   mode "0600"
   content ssh_keys.join("\n")
end

That's idempotent, you don't need the action :nothing or any notifications or subscriptions, you can push new keys out and it'll correctly update, gets the job done with fewer resources, etc.  Similarly executing to su is a huge antipattern, so you can replace the rest of that.




--
Regards,

Douglas Garstang
http://www.linkedin.com/in/garstang
Email: " target="_blank">
Cell: +1-805-340-5627




--



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