145 lines
4.0 KiB
Bash
Executable File
145 lines
4.0 KiB
Bash
Executable File
#!/bin/bash
|
|
# Configure systemd-resolved it to forward requests for a specific domain to Consul. This script has been tested
|
|
# with the following operating systems:
|
|
#
|
|
# 1. Ubuntu 18.04
|
|
# See https://learn.hashicorp.com/consul/security-networking/forwarding#systemd-resolved-setup for more details
|
|
# Github Issue: https://github.com/hashicorp/consul/issues/4155
|
|
|
|
set -e
|
|
|
|
readonly DEFAULT_CONSUL_DOMAIN="consul"
|
|
readonly DEFAULT_CONSUL_IP="127.0.0.1"
|
|
readonly DEFAULT_CONSUL_DNS_PORT=8600
|
|
|
|
readonly SYSTEMD_RESVOLDED_CONFIG_FILE="/etc/systemd/resolved.conf"
|
|
|
|
readonly SCRIPT_NAME="$(basename "$0")"
|
|
|
|
function print_usage {
|
|
echo
|
|
echo "Usage: setup-systemd-resolved [OPTIONS]"
|
|
echo
|
|
echo "Configure systemd-resolved to forward requests for a specific domain to Consul. This script has been tested with Ubuntu 18.04."
|
|
echo
|
|
echo "Options:"
|
|
echo
|
|
echo -e " --consul-domain\tThe domain name to point to Consul. Optional. Default: $DEFAULT_CONSUL_DOMAIN."
|
|
echo -e " --consul-ip\t\tThe IP address to use for Consul. Optional. Default: $DEFAULT_CONSUL_IP."
|
|
echo -e " --consul-dns-port\tThe port Consul uses for DNS. Optional. Default: $DEFAULT_CONSUL_DNS_PORT."
|
|
echo
|
|
echo "Example:"
|
|
echo
|
|
echo " setup-systemd-resolved"
|
|
}
|
|
|
|
function log {
|
|
local -r level="$1"
|
|
local -r message="$2"
|
|
local -r timestamp=$(date +"%Y-%m-%d %H:%M:%S")
|
|
>&2 echo -e "${timestamp} [${level}] [$SCRIPT_NAME] ${message}"
|
|
}
|
|
|
|
function log_info {
|
|
local -r message="$1"
|
|
log "INFO" "$message"
|
|
}
|
|
|
|
function log_warn {
|
|
local -r message="$1"
|
|
log "WARN" "$message"
|
|
}
|
|
|
|
function log_error {
|
|
local -r message="$1"
|
|
log "ERROR" "$message"
|
|
}
|
|
|
|
function assert_not_empty {
|
|
local -r arg_name="$1"
|
|
local -r arg_value="$2"
|
|
|
|
if [[ -z "$arg_value" ]]; then
|
|
log_error "The value for '$arg_name' cannot be empty"
|
|
print_usage
|
|
exit 1
|
|
fi
|
|
}
|
|
|
|
function install_dependencies {
|
|
local -r consul_ip="$1"
|
|
|
|
log_info "Installing dependencies"
|
|
sudo apt-get update -y
|
|
echo iptables-persistent iptables-persistent/autosave_v4 boolean true | sudo debconf-set-selections
|
|
echo iptables-persistent iptables-persistent/autosave_v6 boolean true | sudo debconf-set-selections
|
|
sudo apt-get install -y iptables-persistent
|
|
}
|
|
|
|
function configure_systemd_resolved {
|
|
local -r consul_domain="$1"
|
|
local -r consul_ip="$2"
|
|
local -r consul_port="$3"
|
|
|
|
UBUNTU_VERSION=`lsb_release -s -r`
|
|
if [ "$UBUNTU_VERSION" == "18.04" ]; then
|
|
log_info "Configuring systemd-resolved to forward lookups of the '$consul_domain' domain to $consul_ip:$consul_port in $CONSUL_DNS_MASQ_CONFIG_FILE"
|
|
|
|
sudo iptables -t nat -A OUTPUT -d localhost -p udp -m udp --dport 53 -j REDIRECT --to-ports $consul_port
|
|
sudo iptables -t nat -A OUTPUT -d localhost -p tcp -m tcp --dport 53 -j REDIRECT --to-ports $consul_port
|
|
sudo iptables-save | sudo tee /etc/iptables/rules.v4
|
|
sudo ip6tables-save | sudo tee /etc/iptables/rules.v6
|
|
sudo sed -i "s/#DNS=/DNS=${consul_ip}/g" "$SYSTEMD_RESVOLDED_CONFIG_FILE"
|
|
sudo sed -i "s/#Domains=/Domains=~${consul_domain}/g" "$SYSTEMD_RESVOLDED_CONFIG_FILE"
|
|
else
|
|
log_error "Cannot install on this OS."
|
|
exit 1
|
|
fi
|
|
}
|
|
|
|
function install {
|
|
local consul_domain="$DEFAULT_CONSUL_DOMAIN"
|
|
local consul_ip="$DEFAULT_CONSUL_IP"
|
|
local consul_dns_port="$DEFAULT_CONSUL_DNS_PORT"
|
|
|
|
while [[ $# > 0 ]]; do
|
|
local key="$1"
|
|
|
|
case "$key" in
|
|
--consul-domain)
|
|
assert_not_empty "$key" "$2"
|
|
consul_domain="$2"
|
|
shift
|
|
;;
|
|
--consul-ip)
|
|
assert_not_empty "$key" "$2"
|
|
consul_ip="$2"
|
|
shift
|
|
;;
|
|
--consul-dns-port)
|
|
assert_not_empty "$key" "$2"
|
|
consul_dns_port="$2"
|
|
shift
|
|
;;
|
|
--help)
|
|
print_usage
|
|
exit
|
|
;;
|
|
*)
|
|
log_error "Unrecognized argument: $key"
|
|
print_usage
|
|
exit 1
|
|
;;
|
|
esac
|
|
|
|
shift
|
|
done
|
|
|
|
log_info "Configuring systemd-resolved"
|
|
install_dependencies
|
|
configure_systemd_resolved "$consul_domain" "$consul_ip" "$consul_dns_port"
|
|
log_info "systemd-resolved configured!"
|
|
}
|
|
|
|
install "$@"
|