[CI] collect any coredumps present on the hypervisors

.github/actions/test/integration/build/dev-user-butane.yaml

@@ -56,3 +56,30 @@ storage:
     contents:
       inline: |
         OCI_REPO=ghcr.io/gardenlinux/gardenlinux-ccloud
+  # Enable unlimited core dumps for all systemd services
+  - path: /etc/systemd/system.conf.d/10-core.conf
+    mode: 0644
+    contents:
+      inline: |
+        [Manager]
+        DefaultLimitCORE=infinity
+  # Configure systemd-coredump with reasonable limits
+  - path: /etc/systemd/coredump.conf.d/50-ci-core.conf
+    mode: 0644
+    contents:
+      inline: |
+        [Coredump]
+        Storage=external
+        ProcessSizeMax=3G
+        ExternalSizeMax=3G
+        MaxUse=2G
+        KeepFree=1G
+        Compress=yes
+  # Set kernel core pattern to use systemd-coredump
+  - path: /etc/sysctl.d/50-core.conf
+    mode: 0644
+    contents:
+      inline: |
+        kernel.core_pattern=|/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h
+        kernel.core_pipe_limit=16
+        fs.suid_dumpable=2

.github/actions/test/integration/collect-logs/action.yml

@@ -39,9 +39,44 @@ runs:
       run: |
         sudo chmod 644 *.log
 
-    - name: Upload artifacts
+    - name: Collect coredumps from hypervisors
+      shell: bash
+      run: |
+        KEY=/opt/ssh_host_ed25519_key
+        SSH_OPTS="-i $KEY -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null"
+        USER="root"
+
+        for HV_NAME in HV1 HV2; do
+          IP="192.168.122.$([[ $HV_NAME == HV1 ]] && echo 2 || echo 3)"
+
+          ssh $SSH_OPTS $USER@$IP "
+            # Only proceed if coredumps exist
+            if coredumpctl list --no-legend 2>/dev/null | grep -q .; then
+              mkdir -p /tmp/coredumps-$HV_NAME
+              for id in \$(coredumpctl list --no-legend 2>/dev/null | awk '{print \$5}'); do
+                echo Processing core \$id
+                coredumpctl info \$id > /tmp/coredumps-$HV_NAME/info-\$id.txt 2>/dev/null || true
+                coredumpctl dump \$id > /tmp/coredumps-$HV_NAME/core-\$id 2>/dev/null || true
+              done
+            else
+              echo 'No coredumps present on $HV_NAME'
+            fi
+          " || true
+
+          if ssh $SSH_OPTS $USER@$IP "[ -d /tmp/coredumps-$HV_NAME ] && [ -n \"\$(ls /tmp/coredumps-$HV_NAME 2>/dev/null)\" ]"; then
+            scp -r $SSH_OPTS $USER@$IP:/tmp/coredumps-$HV_NAME ./ || true
+          fi
+         done
+
+    - name: Upload debug logs
       uses: actions/upload-artifact@v4
       with:
         name: debug-logs
         path: "*.log"
 
+    - name: Upload coredumps (if any exist)
+      uses: actions/upload-artifact@v4
+      if: ${{ hashFiles('coredumps-*/**') != '' }}
+      with:
+        name: coredumps
+        path: coredumps-*/