My script to add a peer in DN42.

dn42-peer.sh

#!/bin/sh

if [ "$(id -u -n)" != "root" ]; then
    echo "You need to run this script as root"
    exit 1
fi

WG_PRIVKEY=
WG_PUBKEY=

LINK_LOCAL_ADDR=
IPV4_ADDR=
IPV6_ADDR=

if [ "$(echo $WG_PRIVKEY | wg pubkey)" != "$WG_PUBKEY" ]; then
    echo "WireGuard key integrity check failed"
    exit 1
fi

read -p "Peer ASN: " -e -i "424242" PEER_ASN

PEER_ASN_NUMBER=$(echo "$PEER_ASN" | tr -cd "[:digit:]")
if [ "$PEER_ASN_NUMBER" != "$PEER_ASN" ]; then
    echo "Invalid peer ASN"
    exit 1
fi
if [ "$PEER_ASN" -le 0 -o "$PEER_ASN" -ge "$((2 ** 32))" ]; then
    echo "Invalid peer ASN"
    exit 1
fi

if [ "$PEER_ASN" -ge 4242420000 -a "$PEER_ASN" -le 4242423999 ]; then
    LISTEN_PORT=$((20000 + "$PEER_ASN" % 10000))
    PEER_HANDLE=$(("$PEER_ASN" % 10000))
else
    LISTEN_PORT=$((30000 + "$PEER_ASN" % 1000))
    PEER_HANDLE="as$PEER_ASN"
fi

read -p "Local link-local address: " -e -i "$LINK_LOCAL_ADDR" LINK_LOCAL_ADDR
if [ -z "$LINK_LOCAL_ADDR" ]; then
    echo "Invalid local link-local address"
    exit 1
fi

read -p "Peer WireGuard public key: " PEER_PUBKEY
if [ -z "$PEER_PUBKEY" ]; then
    echo "Invalid peer WireGuard public key"
    exit 1
fi

INTERFACE_NAME="dn42-$PEER_HANDLE"

WG_CONFIG_FILENAME="/etc/wireguard/$INTERFACE_NAME.conf"

WG_CONFIG="[Interface]
PrivateKey = $WG_PRIVKEY
Address = $LINK_LOCAL_ADDR
PostUp = ip addr add $IPV4_ADDR/32 dev %i
PostUp = ip addr add $IPV6_ADDR/128 dev %i
ListenPort = $LISTEN_PORT
Table = off

[Peer]
PublicKey = $PEER_PUBKEY
"

read -p "WireGuard preshared key (optional): " WG_PSK
if [ -n "$WG_PSK" ]; then
    WG_CONFIG+="PresharedKey = $WG_PSK
"
fi

read -p "Peer endpoint (optional): " PEER_ENDPOINT
if [ -n "$PEER_ENDPOINT" ]; then
    WG_CONFIG+="EndPoint = $PEER_ENDPOINT
"
fi

WG_CONFIG+="AllowedIPs = 172.16.0.0/12, 10.0.0.0/8, fd00::/8, fe80::/64
"

read -p "Peer link-local address: " PEER_LINK_LOCAL_ADDR
if [ -z "$PEER_LINK_LOCAL_ADDR" ]; then
    echo "Invalid peer link-local address"
    exit 1;
fi

BIRD_PROTOCOL_NAME="dn42_$PEER_HANDLE"

BIRD_CONFIG_FILENAME="/etc/bird/peers/$BIRD_PROTOCOL_NAME.conf"

BIRD_CONFIG="protocol bgp $BIRD_PROTOCOL_NAME from dnpeers {
    neighbor $PEER_LINK_LOCAL_ADDR%'$INTERFACE_NAME' as $PEER_ASN;
    direct;
}
"
echo

echo "========== $WG_CONFIG_FILENAME =========="
echo "$WG_CONFIG"


echo "========== $BIRD_CONFIG_FILENAME =========="
echo "$BIRD_CONFIG"

read -p "Confirm? (YES) " CONFIRM
if [ "$CONFIRM" != "YES" ]; then
    echo "Abort"
    exit 1
fi

echo -n "$WG_CONFIG" > "$WG_CONFIG_FILENAME"

chmod 600 "$WG_CONFIG_FILENAME"

systemctl enable --now "wg-quick@$INTERFACE_NAME"

echo -n "$BIRD_CONFIG" > "$BIRD_CONFIG_FILENAME"

chown bird:bird "$BIRD_CONFIG_FILENAME"

birdc configure