#!/bin/bash
set -e

source /etc/terraform_environment

SERVER_ARGS=""
UI_DIR="null"
HTTP_CLIENT_ADDR="127.0.0.1"

echo "Installing Consul..."
pushd /tmp
wget https://dl.bintray.com/mitchellh/consul/0.4.1_linux_amd64.zip -O consul.zip
unzip consul.zip >/dev/null
chmod +x consul
mv consul /usr/local/bin/consul
mkdir -p /etc/consul.d
mkdir -p /mnt/consul/data
mkdir -p /etc/service
rm /tmp/consul.zip
popd

if [[ "${ROLE}" == *consul-server* ]]; then
    echo "Configure as Consul Server..."

    SERVER_ARGS="-server -bootstrap-expect=3"
else
    echo "Configure as Consul Client..."
fi

if [[ "${ROLE}" == *consul-ui* ]]; then
    echo "Installing Consul UI..."
    pushd /tmp
    wget https://dl.bintray.com/mitchellh/consul/0.4.1_web_ui.zip -O consul-ui.zip
    unzip consul-ui.zip >/dev/null
    mkdir -p /mnt/consul/ui
    mv dist/* /mnt/consul/ui/
    rm /tmp/consul-ui.zip
    popd

    HTTP_CLIENT_ADDR="0.0.0.0"
    UI_DIR="\"/mnt/consul/ui\""
fi

# Configuration file
echo "Creating configuration..."
cat >/etc/consul.d/config.json << EOF
{
    "addresses"                   : {
        "http" : "${HTTP_CLIENT_ADDR}"
    },
    "ports"                       : {
        "dns" : 53
    },
    "recursor"                    : "10.0.0.2",
    "disable_anonymous_signature" : true,
    "disable_update_check"        : true,
    "data_dir"                    : "/mnt/consul/data",
    "ui_dir"                      : $UI_DIR
}
EOF
chmod 0644 /etc/consul.d/config.json

# Setup the join address
echo "Configure IPs..."
cat >/etc/service/consul-join << EOF
export CONSUL_JOIN="10.0.1.10 10.0.1.11 10.0.1.12"
EOF
chmod 0644 /etc/service/consul-join

# Configure the server
echo "Configure server..."
cat >/etc/service/consul << EOF
export CONSUL_FLAGS="${SERVER_ARGS}"
EOF
chmod 0644 /etc/service/consul

# Add "first start" join service
echo "Creating 'join' service..."
cat >/etc/init/consul-join.conf <<"EOF"
description "Join the consul cluster"

start on started consul
stop on stopped consul

task

script
  if [ -f "/etc/service/consul-join" ]; then
    . /etc/service/consul-join
  fi

  # Keep trying to join until it succeeds
  set +e
  while :; do
    logger -t "consul-join" "Attempting join: ${CONSUL_JOIN}"
    /usr/local/bin/consul join \
      ${CONSUL_JOIN} \
      >>/var/log/consul-join.log 2>&1
    [ $? -eq 0 ] && break
    sleep 5
  done

  logger -t "consul-join" "Join success!"
end script
EOF
chmod 0644 /etc/init/consul-join.conf

# Add actual service
echo "Creating service..."
cat >/etc/init/consul.conf <<"EOF"
description "Consul agent"

start on runlevel [2345]
stop on runlevel [!2345]

respawn

script
  if [ -f "/etc/service/consul" ]; then
    . /etc/service/consul
  fi

  # Make sure to use all our CPUs, because Consul can block a scheduler thread
  export GOMAXPROCS=`nproc`

  exec /usr/local/bin/consul agent \
    -config-dir="/etc/consul.d" \
    ${CONSUL_FLAGS} \
    >>/var/log/consul.log 2>&1
end script
EOF
chmod 0644 /etc/init/consul.conf

# Start service
echo "Starting service..."
initctl start consul