#!/bin/sh

set -e

# Default if not supplied - same as weave net default
IPALLOC_RANGE=${IPALLOC_RANGE:-10.32.0.0/12}
HTTP_ADDR=${WEAVE_HTTP_ADDR:-127.0.0.1:6784}
STATUS_ADDR=${WEAVE_STATUS_ADDR:-0.0.0.0:6782}
HOST_ROOT=${HOST_ROOT:-/host}
CONN_LIMIT=${CONN_LIMIT:-30}

# Check if the IP range overlaps anything existing on the host
/usr/bin/weaveutil netcheck $IPALLOC_RANGE weave

# Default for network policy
EXPECT_NPC=${EXPECT_NPC:-1}

# kube-proxy requires that bridged traffic passes through netfilter
if ! BRIDGE_NF_ENABLED=$(cat /proc/sys/net/bridge/bridge-nf-call-iptables); then
    echo "Cannot detect bridge-nf support - network policy and iptables mode kubeproxy may not work reliably" >&2
else
    if [ "$BRIDGE_NF_ENABLED" != "1" ]; then
        echo 1 > /proc/sys/net/bridge/bridge-nf-call-iptables
    fi
fi

# Explicitly create the bridge so we can pass --expect-npc
WEAVE_NPC_OPTS="--expect-npc"
if [ "${EXPECT_NPC}" = "0" ]; then
    WEAVE_NPC_OPTS=""
fi

export HOST_ROOT=/host
/home/weave/weave --local create-bridge --force $WEAVE_NPC_OPTS

# Kubernetes sets HOSTNAME to the host's hostname
# when running a pod in host namespace.
NICKNAME_ARG=""
if [ -n "$HOSTNAME" ] ; then
    NICKNAME_ARG="--nickname=$HOSTNAME"
fi

BRIDGE_OPTIONS="--datapath=datapath"
if [ "$(/home/weave/weave --local bridge-type)" = "bridge" ] ; then
    # TODO: Call into weave script to do this
    if ! ip link show vethwe-pcap >/dev/null 2>&1 ; then
        ip link add name vethwe-bridge type veth peer name vethwe-pcap
        ip link set vethwe-bridge up
        ip link set vethwe-pcap up
        ip link set vethwe-bridge master weave
    fi
    BRIDGE_OPTIONS="--iface=vethwe-pcap"
fi

if [ -z "$KUBE_PEERS" ]; then
    if ! KUBE_PEERS=$(/home/weave/kube-peers) || [ -z "$KUBE_PEERS" ]; then
        echo Failed to get peers >&2
        exit 1
    fi
fi

peer_count() {
    echo $#
}

if [ -z "$IPALLOC_INIT" ]; then
    IPALLOC_INIT="consensus=$(peer_count $KUBE_PEERS)"
fi

post_start_actions() {
    # Wait for weave process to become responsive
    while true ; do
        curl $HTTP_ADDR/status >/dev/null 2>&1 && break
        sleep 1
    done

    # Install CNI plugin binary to typical CNI bin location
    # with fall-back to CNI directory used by kube-up on GCI OS
    if ! mkdir -p $HOST_ROOT/opt/cni/bin ; then
        if mkdir -p $HOST_ROOT/home/kubernetes/bin ; then
            export WEAVE_CNI_PLUGIN_DIR=$HOST_ROOT/home/kubernetes/bin
        else
            echo "Failed to install the Weave CNI plugin" >&2
            exit 1
        fi
    fi
    mkdir -p $HOST_ROOT/etc/cni/net.d
    /home/weave/weave --local setup-cni

    # Expose the weave network so host processes can communicate with pods
    /home/weave/weave --local expose $WEAVE_EXPOSE_IP
}

post_start_actions &

exec /home/weave/weaver $EXTRA_ARGS --port=6783 $BRIDGE_OPTIONS \
     --http-addr=$HTTP_ADDR --status-addr=$STATUS_ADDR --docker-api='' --no-dns \
     --ipalloc-range=$IPALLOC_RANGE $NICKNAME_ARG \
     --ipalloc-init $IPALLOC_INIT \
     --conn-limit=$CONN_LIMIT \
     "$@" \
     $KUBE_PEERS