#!/bin/bash
# Hashicorp Consul bootstrap script
# Params:
#   server       : if present, bootstraps a server
#   bind         : bind interface address
#   server-ip    : server ip address

# exit on error
set -e

if [ "$#" -eq 0 ]
then
  echo "No options specified, exiting."
  exit 1
fi

# create directory if doesn't exist and set permissions
mkdir -p /etc/consul.d/ && chown -R consul:consul /etc/consul.d/

# write systemd conf
cat >>/etc/systemd/system/consul.service <<EOF
[Unit]
Description="HashiCorp Consul - A service mesh solution"
Documentation=https://www.consul.io/
Requires=network-online.target
After=network-online.target
ConditionFileNotEmpty=/etc/consul.d/consul.hcl

[Service]
EnvironmentFile=/etc/consul.d/consul.env
User=consul
Group=consul
ExecStart=/usr/bin/consul agent -config-dir=/etc/consul.d/
ExecReload=/bin/kill --signal HUP $MAINPID
KillMode=process
KillSignal=SIGTERM
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

# reload systemd
systemctl daemon-reload

# parameter setup
consultype="client"
bind_ip=null
server_ip=null

# read parameters
while [[ "$#" -gt 0 ]]
do
  case $1 in
    -server)
      consultype="server"
      ;;
    -bind)
      bind_ip="$2"
      ;;
    -server-ip)
      server_ip="$2"
      ;;
  esac
  shift
done

# write config file

if [ $consultype == "client" ]
then

  cat >> /etc/consul.d/consul.hcl <<EOF
datacenter    = "dc1"
data_dir      = "/opt/consul"
client_addr   = $bind_ip
retry_join    = ["$server_ip"]
EOF
  chmod 640 /etc/consul.d/consul.hcl

else

  cat >> /etc/consul.d/server.hcl <<EOF
datacenter        = "dc1"
data_dir          = "/opt/consul"
bind_addr         = $bind_ip
server            = true
bootstrap_expect  = 1
EOF
  chmod 640 /etc/consul.d/server.hcl

fi

echo "Done! Please launch with systemctl start consul"