gistfile1.txt

resources in cookbook:

user "dnscache" do
  uid 9997
  case node[:platform]
  when "ubuntu","debian"
    gid "nogroup"
  when "redhat", "centos"
    gid "nobody"
  else
    gid "nobody"
  end
  shell "/bin/false"
  home "/home/dnscache"
end

user "dnslog" do
  uid 9998
  case node[:platform]
  when "ubuntu","debian"
    gid "nogroup"
  when "redhat", "centos"
    gid "nobody"
  else
    gid "nobody"
  end
  shell "/bin/false"
  home "/home/dnslog"
end

user "tinydns" do
  uid 9999
  case node[:platform]
  when "ubuntu","debian"
    gid "nogroup"
  when "redhat", "centos"
    gid "nobody"
  else
    gid "nobody"
  end
  shell "/bin/false"
  home "/home/tinydns"
end

entries from /etc/passwd: 

dnscache:x:9997:65534::/home/dnscache:/bin/false
dnslog:x:9998:65534::/home/dnslog:/bin/false
tinydns:x:9999:65534::/home/tinydns:/bin/false

every chef-client run:
[Wed, 11 Feb 2009 13:58:42 -0700] INFO: Altered user[dnscache]
[Wed, 11 Feb 2009 13:58:42 -0700] INFO: Altered user[dnslog]
[Wed, 11 Feb 2009 13:58:42 -0700] INFO: Altered user[tinydns]