jepsen: allow libvirt driver fallback to qemu in CI

Author: bootjp

.github/workflows/jepsen.yml

@@ -62,7 +62,15 @@ jobs:
 
       - name: Bring up Jepsen VMs
         working-directory: jepsen
-        run: vagrant up --provider=libvirt
+        run: |
+          if [ -r /dev/kvm ] && [ -w /dev/kvm ]; then
+            echo "KVM is available. Using kvm driver."
+            export LIBVIRT_DRIVER=kvm
+          else
+            echo "KVM is NOT available or not writable. Falling back to qemu driver (slow)."
+            export LIBVIRT_DRIVER=qemu
+          fi
+          vagrant up --provider=libvirt
 
       - name: Run Jepsen workload
         working-directory: jepsen

jepsen/Vagrantfile

@@ -34,7 +34,7 @@ Vagrant.configure("2") do |config|
         kvm.memory = name == :ctrl ? 4096 : 2048
         kvm.cpus = 2
         # 必要に応じてドライバを指定
-        kvm.driver = 'kvm' 
+        kvm.driver = ENV['LIBVIRT_DRIVER'] || 'kvm'
       end
 
       if name == :ctrl