workflows: add guest OS selection for CI testing

Add support for selecting guest OS in GitHub Actions CI workflows to enable
testing with different distributions. This allows manual validation of guest
OS-specific fixes and provides foundation for automated multi-OS testing.

The implementation adds a workflow_dispatch input for guest OS selection that
gets merged into the kdevops configuration using the existing merge_config.sh
mechanism. Config fragments override the defconfig's default guest OS choice.

Changes:

- Add guest_os workflow_dispatch input with three options:
  * default: Use defconfig's default guest OS (typically Debian 13)
  * debian-13: Force Debian 13 Trixie guest
  * fedora-41: Force Fedora 41 guest

- Update configure action to accept guest_os input and conditionally merge
  the corresponding guestfs config fragment when non-default value is selected

- Create guestfs-debian-13.config fragment for Debian 13 guest configuration
  to complement existing guestfs-fedora-41.config

This enables manual testing of Fedora guests to validate the locale and
package installation fixes from commits d901509 and 3ec8bf0. The guest OS
parameter defaults to 'default' to maintain backward compatibility with
existing workflows.

Future enhancement: Add matrix strategy to automatically test both Debian
and Fedora guests in scheduled CI runs.

Link: https://lore.kernel.org/kdevops/[email protected]/ [1]
Generated-by: Claude AI
Signed-off-by: Daniel Gomez <[email protected]>

Author: dkruces

.github/actions/configure/action.yml

@@ -20,6 +20,10 @@ inputs:
     required: false
     type: string
     default: 'kdevops-ci'
+  guest_os:
+    required: false
+    type: string
+    default: 'default'
 
 runs:
   using: "composite"
@@ -112,11 +116,27 @@ runs:
           echo "Using Linux CI configuration (4GB/8core VMs)"
         fi
 
+        # Configure guest OS if specified
+        GUEST_OS_CONFIG=
+        if [[ "${{ inputs.guest_os }}" != "default" ]]; then
+          GUEST_OS_CONFIG="defconfigs/configs/guestfs-${{ inputs.guest_os }}.config"
+
+          if [[ ! -f "$GUEST_OS_CONFIG" ]]; then
+            echo "Error: Guest OS config not found: $GUEST_OS_CONFIG"
+            exit 1
+          fi
+
+          echo "Using guest OS configuration: $GUEST_OS_CONFIG"
+        else
+          echo "Using default guest OS from defconfig"
+        fi
+
         ./scripts/kconfig/merge_config.sh \
         -n .config \
         defconfigs/configs/diy.config \
         defconfigs/configs/ci.config \
-        ${VM_CONFIG_ARG}
+        ${VM_CONFIG_ARG} \
+        ${GUEST_OS_CONFIG}
 
     - name: Run kdevops make
       shell: bash

.github/workflows/kdevops.yml

@@ -87,6 +87,15 @@ on:
         options:
           - 'kdevops-ci'
           - 'linux-ci'
+      guest_os:
+        description: 'Guest OS for testing'
+        required: false
+        default: 'default'
+        type: choice
+        options:
+          - default      # Use defconfig's default (typically Debian 13 on debian hosts)
+          - debian-13    # Force Debian 13 Trixie
+          - fedora-41    # Force Fedora 41
       tests:
         description: 'Custom test to run (for kdevops-ci mode only)'
         required: false
@@ -230,6 +239,7 @@ jobs:
         uses: ./.github/actions/configure
         with:
           ci_workflow: ${{ matrix.ci_workflow }}
+          guest_os: ${{ github.event.inputs.guest_os || 'default' }}
           kernel_ref: >-
             ${{
               github.event_name == 'schedule' && needs.generate_kernel_ref.outputs.kernel_ref

defconfigs/configs/guestfs-debian-13.config

@@ -0,0 +1,3 @@
+CONFIG_GUESTFS_DEBIAN=y
+CONFIG_GUESTFS_DEBIAN_TRIXIE=y
+CONFIG_VIRT_BUILDER_OS_VERSION="debian-13"