Skip disks listed in DISK_DEVS that are not present on the machine

[nabeya11]

Anaconda aborts with KickstartParseError when a disk listed in ignoredisk --only-use or clearpart --drives does not exist, so one DISK_DEVS value could not cover machines with different disk layouts.
Generate the two commands in %pre from the DISK_DEVS entries that actually exist and pull them in via %include, making DISK_DEVS a candidate list. Skipped disks are logged to ks-pre.log.
No behavior change when all listed disks exist: the generated commands are identical to the previous static ones.

c.f. https://pykickstart.readthedocs.io/en/latest/kickstart-examples.html

[Copilot]

Pull request overview

This PR updates the Kickstart generation flow so DISK_DEVS can be a candidate list: disks that don’t exist on the target machine are skipped in %pre, avoiding Anaconda/pykickstart parse failures when ignoredisk --only-use / clearpart --drives reference non-existent devices.

Changes:

• Generate ignoredisk and clearpart directives in %pre based on which /dev/<disk> entries from DISK_DEVS actually exist, then pull them in via %include /tmp/ks.diskdevs.cfg.
• Update documentation to clarify that DISK_DEVS may include disks that aren’t present and will be skipped.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
README.md	Clarifies DISK_DEVS semantics as a candidate list with skipping behavior.
ks.tpl.cfg	Replaces static ignoredisk/clearpart directives with a %pre-generated include file derived from present disks.

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[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (2)

ks.tpl.cfg:63

• @@DISK_DEVS@@ is inserted into a shell command unquoted, so any characters like $(), backticks, or globs in the value would be evaluated by the shell during %pre. Even if this is usually admin-provided, quoting the template substitution avoids accidental breakage and removes an easy injection footgun.

for dev in $(echo @@DISK_DEVS@@ | tr "," " ")

ks.tpl.cfg:79

• When diskdevs is empty, the generated include file contains ignoredisk --only-use= / clearpart ... --drives=, which is invalid kickstart syntax and can fail parsing. It’s better to fail fast in %pre with a clear log message (and optionally validate that MAIN_DISK is among the detected disks) rather than emitting invalid directives.

if [ -z "${diskdevs}" ]
then
  echo "no disks in DISK_DEVS (@@DISK_DEVS@@) found"
fi
cat > /tmp/ks.diskdevs.cfg <<EOF