Bug 1595911

1. Proposed title of this feature request  
   Making `adcli` more resilient when FQDN isn't in gethostname() results

2. Who is the customer behind the request?  
   Account: University Of Central Florida (1295742)
   TAM customer:  Not that I can tell
   SRM customer:  Not that I can tell
   Strategic:  Not that I can tell
  

3. What is the nature and description of the request?  
   This customer has a large number of RHEL hosts joined to Active Directory with `adcli`.  Some return a FQDN with `hostname` and some return a short name.  Having the short name returned with `hostname` is preferable for some of their internal operations.

   After joining the servers to AD, the servers with shortname `hostname` output had their DNS records  scavenged by AD because their TTL had not been updated.  The workaround is to have "ad_hostname=fqdn" specified in sssd.conf.

   If a FQDN is required to properly join a RHEL host to Active Directory with `adcli`, and the RHEL host returns a shortname with `hostname`, but `hostname -f` returns the FQDN, would it be possible to have `adcli` be more resilient and perhaps get the fqdn from /etc/hosts or concatenate the shortname with the domain it's being joined to?



4. Why does the customer need this? (List the business requirements here)  
   The customer is asking "if adcli truly needs a FQDN, why does it not use `hostname -f`?" which returns the FQDN in their environment.  Having to configure all their hosts to return a FQDN for `hostname` output would be a lot of work.


5. How would the customer like to achieve this? (List the functional requirements here)  
   Have `adcli` require `hostname -f` output instead of `hostname` if it truly requires a FQDN


6. For each functional requirement listed, specify how Red Hat and the customer can test to confirm the requirement is successfully implemented.  
   The customer can verify if DNS records are updated and an AD join persists for hosts that have shortnames
   

7. Is there already an existing RFE upstream or in Red Hat Bugzilla?  
   -- Related bug:  "Bug 86107 - adcli not using fqdn" -- https://bugs.freedesktop.org/show_bug.cgi?id=86107
   -- Upstream bug and discussion:  "DDNS not working due to non FQDN hostname" -- https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.org/thread/QHBRCO2JR36PT5F4ZPZNGUHCEE5E4G42/
   -- RFE for RHEL 6 was opened as well but will most likely not be acted upon: https://bugzilla.redhat.com/show_bug.cgi?id=1592974


8. Does the customer have any specific timeline dependencies and which release would they like to target (i.e. RHEL5, RHEL6)?
   The customer has RHEL 7 hosts that they are joining to AD.


9. Is the sales team involved in this request and do they have any additional input?  
   Not at the moment


10. List any affected packages or components.  
    adcli, sssd, Active Directory environment


11. Would the customer be able to assist in testing this functionality if implemented?
    Yes


___________________________________________________


Additional Additional information:

1) The `hostname` output only has a shortname:

   $ cat hostname 
   net1682

2) Similarly, the kernel is only aware of the short name:

   $ cat proc/sys/kernel/hostname 
   net1682

3) But /etc/sysconfig/network has the FQDN:

   $ cat etc/sysconfig/network
   NETWORKING=yes
   HOSTNAME=net1682.net.ucf.edu

4) And the shortname is also in the interface's network script:

   $ cat etc/sysconfig/network-scripts/ifcfg-eth0
   DEVICE="eth0"
   BOOTPROTO="dhcp"
   #GATEWAY="10.169.200.1"
   HOSTNAME="net1682"            <---
   HWADDR="00:50:56:B1:8D:60"
   #IPADDR="10.169.200.79"
   IPV6INIT="no"
   MTU="1500"
   #NETMASK="255.255.255.0"
   NM_CONTROLLED="yes"
   ONBOOT="yes"
   TYPE="Ethernet"
   UUID="ddd7b117-364c-46be-b373-fc6f7c52e3d4"