cat <<EOF > Dockerfile
FROM k8s.gcr.io/node-problem-detector:v0.8.8
COPY rootfs /
EOF

mkdir -p rootfs/plugins/

cat <<EOF > rootfs/plugins/contrack.sh
#!/bin/bash

OK=0
NONOK=1
UNKNOWN=2

[ -f /proc/sys/net/netfilter/nf_conntrack_max ] || exit $UNKNOWN
[ -f /proc/sys/net/netfilter/nf_conntrack_count ] || exit $UNKNOWN

conntrack_max=$(cat /proc/sys/net/netfilter/nf_conntrack_max)
conntrack_count=$(cat /proc/sys/net/netfilter/nf_conntrack_count)

if (( conntrack_count >= conntrack_max )); then
    echo "Conntrack table full"
    exit $NONOK
fi

exit $OK
EOF

cat <<EOF > rootfs/plugins/resolv.sh
#!/bin/bash

OK=0
NONOK=1

getent ahostsv4 kubernetes.default.svc > /dev/null
if [ $? -ne 0 ]; then
    echo "Resolv kubernetes.default.svc dont work"
    exit $NONOK
fi

exit $OK
EOF