images/kubekins*: apply default Docker daemon.json

- Use the overlay2 storage driver
- Disable the containerd snapshotter.

Without this config we are hitting bugs when doing
'docker pull', 'docker save' from kubekins and then
trying to 'ctr import' the resulted tar files.

Author: neolit123

images/bootstrap/runner.sh

@@ -42,20 +42,30 @@ if [[ "${DOCKER_IN_DOCKER_ENABLED}" == "true" ]]; then
     echo "Docker in Docker enabled, initializing..."
     printf '=%.0s' {1..80}; echo
 
-    # optionally enable CDI in Docker/containerd (see https://github.com/cncf-tags/container-device-interface?tab=readme-ov-file#docker-configuration)
-    export CDI_IN_DOCKER_ENABLED=${CDI_IN_DOCKER_ENABLED:-false}
-    if [[ "${CDI_IN_DOCKER_ENABLED}" == "true" ]]; then
-        echo "Enabling CDI for Docker."
-        mkdir -p /etc/docker/
-        cat >/etc/docker/daemon.json <<EOF
+    DAEMON_JSON=/etc/docker/daemon.json
+    echo "Applying Docker config."
+
+    mkdir -p /etc/docker
+
+    # Use the overlay2 storage driver and disable the containerd snapshotter
+    cat ${DAEMON_JSON} > /dev/null <<EOF
 {
-  "features": {
-    "cdi": true
-  }
+    "storage-driver": "overlay2",
+    "features": {
+        "containerd-snapshotter": false
+    }
 }
 EOF
+
+    # Optionally enable CDI in Docker/containerd (see https://github.com/cncf-tags/container-device-interface?tab=readme-ov-file#docker-configuration)
+    export CDI_IN_DOCKER_ENABLED=${CDI_IN_DOCKER_ENABLED:-false}
+    if [[ "${CDI_IN_DOCKER_ENABLED}" == "true" ]]; then
+        echo "Enabling CDI for Docker."
+        jq '.features += {"cdi": true}' ${DAEMON_JSON} | tee ${DAEMON_JSON} > /dev/null
     fi
 
+    cat ${DAEMON_JSON}
+
     # docker v27+ has ipv6 by default, but not all e2e hosts have everything
     # we need enabled by default
     # enable ipv6

images/kubekins-e2e-v2/runner.sh

@@ -48,6 +48,22 @@ if [[ "${DOCKER_IN_DOCKER_ENABLED}" == "true" ]]; then
     # Fix ulimit issue
     sed -i 's|ulimit -Hn|ulimit -n|' /etc/init.d/docker || true
 
+    # Use the overlay2 storage driver and disable the containerd snapshotter
+    DAEMON_JSON=/etc/docker/daemon.json
+    echo "Applying Docker config."
+
+    mkdir -p /etc/docker
+    cat ${DAEMON_JSON} > /dev/null <<EOF
+{
+    "storage-driver": "overlay2",
+    "features": {
+        "containerd-snapshotter": false
+    }
+}
+EOF
+
+    cat ${DAEMON_JSON}
+
     # start the docker daemon
     service docker start
     # the service can be started but the docker socket not ready, wait for ready