Generate NetworkManager .nmconnection keyfile for Leaseweb dedicated servers (queries Leaseweb API, outputs to stdout)

leaseweb-nmconnection.sh

#!/usr/bin/env bash
# Generate a NetworkManager .nmconnection keyfile for a Leaseweb dedicated server.
# Queries the Leaseweb API for network details and writes keyfile to stdout.
#
# Usage: LSW_API_KEY=xxx ./leaseweb-nmconnection.sh <server-id>
#
# Dependencies: curl, jq
# Output: .nmconnection keyfile on stdout; progress/errors on stderr

set -euo pipefail

die() { echo "error: $*" >&2; exit 1; }
log() { echo ":: $*" >&2; }

# -- deps --
for cmd in curl jq; do
	command -v "$cmd" >/dev/null 2>&1 || die "$cmd not found (apt-get install -y $cmd)"
done

# -- inputs --
[[ ${1:-} ]] || die "usage: $0 <server-id>"
SERVER_ID="$1"
: "${LSW_API_KEY:?set LSW_API_KEY}"

LSW_API="https://api.leaseweb.com/bareMetals/v2/servers"

lsw_get() {
	local url="$1"
	log "GET $url"
	curl -sf -H "X-Lsw-Auth: ${LSW_API_KEY}" "$url"
}

# -- fetch server info --
server_json=$(lsw_get "${LSW_API}/${SERVER_ID}")
server_mac=$(jq -r '.networkInterfaces.public.mac // empty' <<<"$server_json")

# fall back to MAC of the default route interface on this host
if [[ -z $server_mac ]]; then
	default_iface=$(ip route show default 2>/dev/null | awk '{print $5; exit}')
	if [[ -n ${default_iface:-} ]]; then
		server_mac=$(ip link show "$default_iface" 2>/dev/null | awk '/ether/ {print $2; exit}')
		log "mac from local interface ${default_iface}=${server_mac}"
	fi
fi

log "mac=${server_mac:-none}"

# -- fetch IPs --
ips_json=$(lsw_get "${LSW_API}/${SERVER_ID}/ips")

# primary IPv4: mainIp=true, version=4, networkType=PUBLIC
ipv4_entry=$(jq -r '[.ips[] | select(.version==4 and .mainIp==true and .networkType=="PUBLIC")] | first' <<<"$ips_json")
[[ $ipv4_entry != "null" ]] || die "no primary public IPv4 found"

ipv4_cidr=$(jq -r '.ip' <<<"$ipv4_entry")
ipv4_gw=$(jq -r '.gateway' <<<"$ipv4_entry")
ipv4_addr="${ipv4_cidr%/*}"
ipv4_mask="${ipv4_cidr#*/}"
log "ipv4=${ipv4_addr}/${ipv4_mask} gw=${ipv4_gw}"

# IPv6: version=6, networkType=PUBLIC (may not exist)
ipv6_entry=$(jq -r '[.ips[] | select(.version==6 and .networkType=="PUBLIC")] | first // empty' <<<"$ips_json")

if [[ -n $ipv6_entry ]]; then
	ipv6_cidr=$(jq -r '.ip' <<<"$ipv6_entry")
	ipv6_gw=$(jq -r '.gateway' <<<"$ipv6_entry")
	# strip underscores that Leaseweb sometimes includes in IPv6 addresses
	ipv6_cidr="${ipv6_cidr//_/}"
	ipv6_gw="${ipv6_gw//_/}"
	ipv6_addr="${ipv6_cidr%/*}"
	ipv6_mask="${ipv6_cidr#*/}"
	log "ipv6=${ipv6_addr}/${ipv6_mask} gw=${ipv6_gw}"
else
	log "warning: no IPv6 address found — request one via the Leaseweb dashboard"
fi

# -- generate keyfile --
log "generating keyfile"

cat <<EOF
[connection]
id=static
type=ethernet
autoconnect-priority=1

[ipv4]
method=manual
address1=${ipv4_addr}/${ipv4_mask},${ipv4_gw}
dns=1.1.1.1;1.0.0.1;

EOF

if [[ -n ${ipv6_entry:-} ]]; then
	cat <<EOF
[ipv6]
method=manual
address1=${ipv6_addr}/${ipv6_mask},${ipv6_gw}
dns=2606:4700:4700::1111;2606:4700:4700::1001;

EOF
else
	cat <<EOF
[ipv6]
method=disabled

EOF
fi

if [[ -n ${server_mac:-} ]]; then
	cat <<EOF
[ethernet]
mac-address=${server_mac}
EOF
else
	cat <<EOF
[ethernet]
EOF
fi

log "done"