Cache sysupgrade files across runs.

Author: daztucker

.github/workflows/vm.yml

@@ -339,12 +339,35 @@ jobs:
             echo `hostname` `cat $key` >>$sshconf/ssh_known_hosts
           done
 
+    - name: Fetch sysupgrade version
+      run: |
+        ver=$(curl -s https://cdn.openbsd.org/pub/OpenBSD/snapshots/amd64/BUILDINFO)
+        echo "SNAPSHOT_VERSION=${ver}" >> $GITHUB_ENV
+    - name: Cache sysupgrade
+      id: cache-sysupgrade
+      uses: actions/cache@v4
+      with:
+        key: openbsd-sysupgrade ${{ env.SNAPSHOT_VERSION }}
+        path: /tmp/_sysupgrade/
+    - name: Restore sysupgrade from cache
+      run: |
+        mkdir -p /tmp/_sysupgrade/
+        rsync -av /tmp/_sysupgrade/ openbsd:/home/_sysupgrade/
     - name: upgrade to latest snapshot
-      run: ssh -q openbsd sysupgrade -s || true
+      run: ssh -q openbsd sysupgrade -s -k || true
     - name: wait for upgrade
       run: |
         SECONDS=0; sleep 10; while ! ssh -q -oConnectTimeout=1 openbsd true; do sleep 10; echo waited ${SECONDS}s; done
         ssh openbsd uname -a
+    - name: retrieve sysupgrade to cache
+      run: rsync -av openbsd:/home/_sysupgrade/ /tmp/_sysupgrade/
+    - name: save sysupgrade cache
+      if: steps.cache-sysupgrade.output.cache-hit != 'true' && ${{ hashFiles('/tmp/_sysupgrade/xshare78.tgz') != '' }}
+      uses: actions/cache/save@v4
+      with:
+        key: openbsd-sysupgrade ${{ env.SNAPSHOT_VERSION }}
+        path: /tmp/_sysupgrade/
+
     - name: checkout upstream source
       shell: openbsd {0}
       run: |