Devise LDAP can't find user, but logs in fine - ruby-on-rails

Question

So when I authorize a user with the devise_ldap_authenticatable gem, I get the following logged information:
LDAP: LDAP dn lookup: sAMAccountName=john.smith
LDAP: LDAP search for login: sAMAccountName=john.smith
LDAP: LDAP search yielded 0 matches
LDAP: Authorizing user lt\john.smith
As I understand it, the search fails to return a user, which I would like to find so I could set other attributes based off of LDAP fields (mainly department).
I've checked that this search should work with the following rake task:
desc "LDAP Test"
task ldap: :environment do
ldap = Net::LDAP.new :host => ENV['LDAP_IP'],
:port => ENV['LDAP_PORT'],
:encryption => :simple_tls,
:base => ENV['LDAP_BASE'],
:auth => {
:method => :simple,
:username => ENV['LDAP_LOGIN'],
:password => ENV['LDAP_PASSWORD']
}
if ldap.bind
ldap.search(:base => ENV['LDAP_BASE'], :filter => Net::LDAP::Filter.eq("sAMAccountName", "john.smith"), :attributes => ["sAMAccountName", "department"], :return_result => false) do |entry|
entry.each do |attr, values|
puts "#{attr}: #{values.first}"
end
end
else
puts "Connection failed! Code: #{ldap.get_operation_result.code}, message: #{ldap.get_operation_result.message}"
end
end
Which returns:
dn: CN=John Smith,OU=Temporary Staff,OU=Users,DC=lt,DC=local
department: Bioinformatics
samaccountname: Johh.Smith
Does anyone know why the login search could be failing? My config files are as follows:
devise.rb:
# ==> LDAP Configuration
config.ldap_logger = true
config.ldap_create_user = true
config.ldap_update_password = false
# config.ldap_config = "#{Rails.root}/config/ldap.yml"
config.ldap_auth_username_builder = Proc.new() {|attribute, login, ldap| "lt\\#{login}"}
# config.ldap_check_group_membership = false
# config.ldap_check_attributes = false
config.ldap_use_admin_to_bind = true
ldap.yml:
development:
host: <%= ENV['LDAP_IP'] %>
port: <%= ENV['LDAP_PORT'] %>
attribute: sAMAccountName
base: <%= ENV['LDAP_BASE'] %>
admin_user: <%= ENV['LDAP_LOGIN'] %>
admin_password: <%= ENV['LDAP_PASSWORD'] %>
ssl: true
# <<: *AUTHORIZATIONS

Answer 1

I would use a packet sniffer like Wireshark to see the difference between the LDAP requests in the rake task vs. devise. The UnboundID LDAP SDK for Java also ships with a tool called LDAPDebugger that you can use as a proxy between your app and Active Directory to decode the traffic.
I hope this helps.