Add new `c9s-rt` variant

I think having an image with RT enabled out of the box just makes
sense.

.github/workflows/build.yaml

@@ -22,7 +22,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: ["fedora", "c9s"]
+        os: ["fedora", "c9s", "c9s-rt"]
     container:
       # Yes, we're using this as a *builder* image.
       image: quay.io/fedora/fedora-coreos:stable

c9s-base.yaml

@@ -0,0 +1,20 @@
+releasever: stream9
+
+repos:
+  - baseos
+  - appstream
+  - coreos-continuous-c9s
+  - bootc-c9s
+
+metadata:
+  name: c9s-oscore
+  summary: CentOS 9 OSCore
+
+repo-packages:
+  - repo: bootc-c9s
+    packages:
+      - bootc
+
+include:
+  - oscore/manifest.yaml
+

c9s-rt.yaml

@@ -0,0 +1,3 @@
+include:
+  - c9s-base.yaml
+  - oscore/kernel-rt.yaml

c9s.yaml

@@ -1,19 +1,4 @@
-releasever: stream9
-
-repos:
-  - baseos
-  - appstream
-  - coreos-continuous-c9s
-  - bootc-c9s
-
-metadata:
-  name: c9s-oscore
-  summary: CentOS 9 OSCore
-
-repo-packages:
-  - repo: bootc-c9s
-    packages:
-      - bootc
-
 include:
-  - oscore/manifest.yaml
+  - c9s-base.yaml
+  - oscore/kernel.yaml
+

fedora.yaml

@@ -12,6 +12,7 @@ metadata:
 
 include:
   - oscore/manifest.yaml
+  - oscore/kernel.yaml
 
 repo-packages:
   - repo: bootc-fedora

oscore/bootc.yaml

@@ -1,7 +1,7 @@
 # A relatively minimal base, but we also do include linux-firmware so
 # we can be directly booted on metal.
 packages:
- - kernel systemd
+ - systemd
  # linux-firmware now a recommends so let's explicitly include it
  # https://gitlab.com/cki-project/kernel-ark/-/commit/32271d0cd9bd52d386eb35497c4876a8f041f70b
  # https://src.fedoraproject.org/rpms/kernel/c/f55c3e9ed8605ff28cb9a922efbab1055947e213?branch=rawhide

oscore/kernel-rt.yaml

@@ -0,0 +1,10 @@
+repos:
+  - rt
+  - nfv
+
+# Enable the "realtime" AKA soft-realtime AKA latency-optimized kernel.
+packages:
+ - kernel-rt-core kernel-rt-modules kernel-rt-modules-extra kernel-rt-kvm
+
+exclude-packages:
+  - kernel-rt-debug-core

oscore/kernel.yaml

@@ -0,0 +1,6 @@
+# Enable the Linux kernel; see also kernel-rt.
+packages:
+ - kernel
+
+exclude-packages:
+  - kernel-debug