Docker(strongSwan + MySQL + bitcoin + Spring Boot)

Written on January 2, 2018

I wanted to get some hands-on experience with Docker and Spring Boot, so I built a Spring Boot webapp, and have put together Docker images to tie it together with Bitcoin Core, strongSwan, and a database. Oh, also, it is absolutely no fun trying to choose a VPN service. I’m not aware of any VPN providers that offer certificate-based authentication for IKEv2/IPsec. Given the current transaction fees and confirmation delays with Bitcoin, it would make sense to go with a different cryptocurrency. You can clone the most up-to-date instance of this project here.

Architecture

There are four Docker containers:

• bitcoin
  • There are shell scripts that are triggered on blocknotify and walletnotify. These make calls to the webapp’s updatePayment and updateConfirmations actions.
• db
  • There are two MySQL databases in this container - one that is primarily used by strongSwan, and the other that is primarily used by the webapp.
• strongswan
  • strongSwan uses the MySQL plugin for its configuration. There is no ipsec.conf or swanctl.conf.
  • There are iptables that are inserted when a client brings up the connection.
    • An iptables -t nat rule is inserted so that traffic is forwarded through
    • Two iptables -t mangle rules are inserted, these are used to get the bandwidth counts.
  • A cron job is used to make calls to write the new bandwidth data to the database; and to clean up any connections
• webapp
  • This is a Spring Boot app which serves as the front-end. Thymeleaf is used for templating, and Gradle is used for building. Bootstrap is used for the UI.
  • The webapp has the Subscription and Payment logic, and is also responsible for issuing certificates based on the user’s CSR.

Requirements

You will need Java, Gradle, and Docker installed.

Set up keystore

sudo apt-get install strongswan (need this for ipsec pki. will move commands to use openssl later)

cd ipsec-pki ; bash -x buildKeystore.sh

Build webapp

./gradlew build buildDocker

Run (this will build the other images)

• docker-compose up -d

Make Payment (this uses the regtest network)

Connect bitcoin wallet

bitcoin-qt -datadir=/home/ram/bob-datadir -port=19444 -rpcport=19332 -rpcuser=bob -rpcpassword=bobpass -connect=172.20.0.1:18333 -regtest -server -listen -debug

Generate block

bitcoin-cli -regtest -rpcport=19332 -rpcuser=bob -rpcpassword=bobpass generate 1