Fedora 27 Anaconda systemd fail, /dev/disk/ by-path enumeration name does not match CentOS/RHEL 7.3, 7.4, 7.5

[Ed Gasiorowski]

Description of problem: in RHEL 7.3, 7.4, and 7.5-SNAP1 using the following Beaker
Kickstart Metadata   

ignoredisk=--only-use=/dev/disk/by-path/platform-APMC0D33:01-ata-1.0
"clearpart=--initlabel --all" zerombr  

On Fedora 27, anaconda fails with the following message: 
http://beaker-controller.rack151.mustanglab.us.amcc/beaker/anamon 
<http://beaker-controller.rack151.mustanglab.us.amcc/beaker/anamon>
 + curl --retry 20 --remote-time -o /tmp/anamon 
http://beaker-controller.rack151.mustanglab.us.amcc/beaker/anamon  
<http://beaker-controller.rack151.mustanglab.us.amcc/beaker/anamon>
% Total    % Received % Xferd  Average Speed   Time    Time     Time  Current  Dload 
Upload   Total   Spent    Left  Speed
   0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0 100  8741 
100  8741    0     0   8741      0  0:00:01 --:--:--  0:00:01 2134k
+ python /tmp/anamon --recipe-id 28293 --xmlrpc-url
http://beaker-controller.rack151.mustanglab.us.amcc:8000/RPC2
<http://beaker-controller.rack151.mustanglab.us.amcc:8000/RPC2> 
/tmp/ks-script-6olvntfg: line 38: python: command not found
An error occurred during reading the kickstart file: The following problem occurred on
line 32 of the kickstart file:
Disk "/dev/disk/by-path/platform-APMC0D33:01-ata-1.0" given in ignoredisk
command does not exist.
The installer will now terminate. Pane is dead

Issue: In RHEL 7.3/7.4/7.5 & CentOS 7.3/7.4, in /dev/disk/by-path/... 
the path name "platform-APMC0D33:01-ata-1.0" has decimal extension i.e.
"1.0"

In Fedora 27, in /dev/disk/by-path/... 
the path name "platform-APMC0D33:01-ata-1" has no decimal extension i.e.
"1"

When using disk specific targeting for OS install on systems with more than 1 installable
device, this inconsistency causes issues with automation and common kickstart

[Peter Robinson]

On Fri, Mar 23, 2018 at 3:37 PM, Ed Gasiorowski <egasiorowski(a)gmail.com&gt; wrote:
>  Description of problem: in RHEL 7.3, 7.4, and 7.5-SNAP1 using the
> following Beaker Kickstart Metadata
>
>  ignoredisk=--only-use=/dev/disk/by-path/platform-APMC0D33:01-ata-1.0
> "clearpart=--initlabel --all" zerombr
>
>  On Fedora 27, anaconda fails with the following message:
>  http://beaker-controller.rack151.mustanglab.us.amcc/beaker/anamon 
> <http://beaker-controller.rack151.mustanglab.us.amcc/beaker/anamon>
>   + curl --retry 20 --remote-time -o /tmp/anamon 
> http://beaker-controller.rack151.mustanglab.us.amcc/beaker/anamon  
> <http://beaker-controller.rack151.mustanglab.us.amcc/beaker/anamon>
>  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current  Dload 
> Upload   Total   Spent    Left  Speed
>     0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0 100  8741
>  100  8741    0     0   8741      0  0:00:01 --:--:--  0:00:01 2134k
>  + python /tmp/anamon --recipe-id 28293 --xmlrpc-url
> http://beaker-controller.rack151.mustanglab.us.amcc:8000/RPC2
> <http://beaker-controller.rack151.mustanglab.us.amcc:8000/RPC2> 
> /tmp/ks-script-6olvntfg: line 38: python: command not found
>  An error occurred during reading the kickstart file: The following problem occurred on
> line 32 of the kickstart file:
>  Disk "/dev/disk/by-path/platform-APMC0D33:01-ata-1.0" given in ignoredisk
> command does not exist.
>  The installer will now terminate. Pane is dead
>
>  Issue: In RHEL 7.3/7.4/7.5 & CentOS 7.3/7.4, in /dev/disk/by-path/...
>  the path name "platform-APMC0D33:01-ata-1.0" has decimal extension i.e.
> "1.0"
>
>  In Fedora 27, in /dev/disk/by-path/...
>  the path name "platform-APMC0D33:01-ata-1" has no decimal extension i.e.
> "1"
>
>  When using disk specific targeting for OS install on systems with more than 1 installable
> device, this inconsistency causes issues with automation and common kickstart 
Looking at a booted mustang system I don't see those names but see the
following:
platform-1a400000.sata-ata-1
platform-1a400000.sata-ata-2

I don't see anything with platform-APM at all. So I suspect something
has changed in the upstream kernel, or more likely that RHEL is
pulling in non upstream patches. Do the RHEL systems have duplicate
names like the above, which would actually be more consistent across
systems that aren't APM anyway, that could be used. Ultimately Fedora
just uses upstream, if Red Hat pulls in various non upstream patch
sets that provide non standard naming there's not much we can do to
address that in Fedora.

Peter