Fix Samba regression from 3.8-14.03

[Mazo]

See thread here from another user: https://forum.rockstor.com/t/3-8-14-03-broke-samba/1726

        Traceback (most recent call last):

File "/opt/rockstor/src/rockstor/rest_framework_custom/generic_view.py", line 40, in _handle_exception
yield
File "/opt/rockstor/src/rockstor/smart_manager/views/samba_service.py", line 44, in get
config = get_global_config()
File "/opt/rockstor/src/rockstor/system/samba.py", line 179, in get_global_config
config[fields[0].strip()] = fields[1].strip()
IndexError: list index out of range

[phillxnet]

@Mazo Thanks for reporting this, I'm having a quick look now and think it's the indented comments within the [global] section of /etc/samba/smb.conf thats causing a simple parsing error.
Currently working on a fix and should be available pretty soon.

[phillxnet]

With the above logging commit we get the following:

[09/Jul/2016 18:38:10] DEBUG [system.samba:182] FIELDS = ['workgroup ', ' mygroup']
[09/Jul/2016 18:38:10] DEBUG [system.samba:183] LEN OF FIELDS = 2
[09/Jul/2016 18:38:10] DEBUG [system.samba:182] FIELDS = ['server string ', ' Samba Server Version %v']
[09/Jul/2016 18:38:10] DEBUG [system.samba:183] LEN OF FIELDS = 2
[09/Jul/2016 18:38:10] DEBUG [system.samba:182] FIELDS = [';\tnetbios name ', ' MYSERVER']
[09/Jul/2016 18:38:10] DEBUG [system.samba:183] LEN OF FIELDS = 2
[09/Jul/2016 18:38:10] DEBUG [system.samba:182] FIELDS = [';\tinterfaces ', ' lo eth0 192.168.12.2/24 192.168.13.2/24']
[09/Jul/2016 18:38:10] DEBUG [system.samba:183] LEN OF FIELDS = 2
[09/Jul/2016 18:38:10] DEBUG [system.samba:182] FIELDS = [';\thosts allow ', ' 127. 192.168.12. 192.168.13.']
[09/Jul/2016 18:38:10] DEBUG [system.samba:183] LEN OF FIELDS = 2
[09/Jul/2016 18:38:10] DEBUG [system.samba:182] FIELDS = [';\tmax protocol ', ' SMB2']
[09/Jul/2016 18:38:10] DEBUG [system.samba:183] LEN OF FIELDS = 2
[09/Jul/2016 18:38:10] DEBUG [system.samba:182] FIELDS = ['# log files split per-machine:']
[09/Jul/2016 18:38:10] DEBUG [system.samba:183] LEN OF FIELDS = 1
[09/Jul/2016 18:38:10] ERROR [storageadmin.util:47] exception: list index out of range
Traceback (most recent call last):
  File "/opt/rockstor/src/rockstor/rest_framework_custom/generic_view.py", line 40, in _handle_exception
    yield
  File "/opt/rockstor/src/rockstor/smart_manager/views/samba_service.py", line 44, in get
    config = get_global_config()
  File "/opt/rockstor/src/rockstor/system/samba.py", line 186, in get_global_config
    config[fields[0].strip()] = fields[1].strip()
IndexError: list index out of range
[09/Jul/2016 18:38:10] DEBUG [storageadmin.util:48] Current Rockstor version: 3.8-14.03

Hence the failed parsing on indented remarks.

[phillxnet]

@schakrava With the 'final field count sanity check' patch:
phillxnet@4ddd2aa
the new code did retrieve [global] options and display them in the new custom options box and didn't trip up on the indented remarks but upon submitting samba config the existing /etc/samba/smb.conf file was found to be empty.

Handing over to you on this one as I suspect you know what's happened on this one already.

[phillxnet]

Extracted "Custom global configuration" displayed with testing channel released code once all indented remarks are removed ie lines such as:

        # log files split per-machine:
        # maximum size of 50KB per log file, then rotate:

Looks like this (note the indent and last line with spaces):

              ; max protocol = SMB2
              ; map hidden = no
              ; add machine script = /usr/sbin/useradd -n -c "Workstation (%u)" -M -d /nohome -s /bin/false "%u"
              ; printcap name = lpstat
              ; logon path = 
              ; domain logons = yes
              ; map archive = no
              load printers = yes
              ; security = user
              ; domain master = yes
              ; delete user script = /usr/sbin/userdel "%u"
              ; add user script = /usr/sbin/useradd "%u" -n -g users
              ; wins support = yes
              ; map system = no
              ; passdb backend = tdbsam
              ; delete user from group script = /usr/sbin/userdel "%u" "%g"
              ; local master = no
              passdb backend = tdbsam
              ; delete group script = /usr/sbin/groupdel "%g"
              workgroup = MYGROUP
              cups options = raw
              ; realm = MY_REALM
              ; password server = <NT-Server-Name>
              max log size = 50
              log file = /var/log/samba/log.%m
              ; wins proxy = yes
              ; hosts allow = 127. 192.168.12. 192.168.13.
              ; dns proxy = yes
              ; wins server = w.x.y.z
              ; os level = 33
              server string = Samba Server Version %v
              ; add group script = /usr/sbin/groupadd "%g"
              ; logon script = %u.bat
              ; map read only = no
              ; store dos attributes = yes
              ; interfaces = lo eth0 192.168.12.2/24 192.168.13.2/24
              ; printing = cups
              security = user
              ; preferred master = yes
              ; netbios name = MYSERVER

[phillxnet]

Submitting the above, which results from removing the indented remarks then results in an empty smb.conf. Was looking for a user applicable edit of config as a quick work around on released testing channel code but looks like there more to this one that I initially though.

[phillxnet]

@schakrava pr ready for testing and review.

Please update the following forum thread with significant development on this issue:
https://forum.rockstor.com/t/3-8-14-03-broke-samba/1726

[schakrava]

Thanks @Mazo and @phillxnet and my apologies for sloppy changes to begin with.

[schakrava]

Fixed by #1386

[phillxnet]

The indicated forum thread has now been updated.