Under the Hood — Running Everything Together

In the previous post of the “Under the hood” series, I explained how payment requests work. In this post, I will show you how to install and run the full set of Swaptacular network nodes on your laptop.

A fair warning: This post may become too technical for the taste of some readers.

Preparing your machine

Because all of the services that we will run here are packaged as docker images, chances are that you will be able to run them on Linux, Windows, or Mac (currently we have x86-64 and ARM64 images). However, the instructions given bellow are for Linux, because I use Linux, and this is the most popular platform for deployment of servers.

You need to install three things on your machine:

1. Docker Engine
2. Docker Compose
3. Git

It should be relatively easy to find detailed instructions on how to install those for most operating systems.

Cloning the Git repositories

We want to run 3 different Swaptacular nodes simultaneously:

1. an accounting authority node,
2. a creditors agent node,
3. a debtors agent node.

The source code for each one of these nodes resides in a separate Git repository. You need to clone each of those 3 repositories separately:

$ git clone https://github.com/swaptacular/swpt_accounts.git
Cloning into 'swpt_accounts'...

$ git clone https://github.com/swaptacular/swpt_creditors.git
Cloning into 'swpt_creditors'...

$ git clone https://github.com/swaptacular/swpt_debtors.git
Cloning into 'swpt_debtors'...

$ ls
swpt_accounts  swpt_creditors  swpt_debtors

Starting the nodes

Open a new terminal for the accounting authority node, and in it, execute the following commands:

$ cd swpt_accounts/
$ cp development.env .env
$ docker-compose -f docker-compose-all.yml up --build
Creating network with the default driver
Building accounts-server
...

Then, open another terminal for the creditors agent node, and in it, execute the commands:

$ cd swpt_creditors/
$ cp development.env .env
$ docker-compose -f docker-compose-all.yml up --build
Creating network with the default driver
Building creditors-server
...

Finally, open a third terminal for the debtors agent node, and in it, execute:

$ cd swpt_debtors/
$ cp development.env .env
$ docker-compose -f docker-compose-all.yml up --build
Creating network with the default driver
Building debtors-server
...

In each of those 3 terminals, a new docker image will be built from source, and then a bunch of docker containers will be started, running the image, along with a bunch of other docker images, downloaded from Internet. The newly created .env files contain basic configuration settings.

Note: You can press Ctrl-C in the terminal, to stop all running containers.

Do not be alarmed by the large amount of spewed log messages. A lot of things need to happen before everything is configured and ready to go! In particular, you will probably see a lot of Connection refused error messages. This happens because every node is constantly trying to connect to its peer nodes, which will continue to fail until all peer nodes are up and running. Also, you may periodically see missed heartbeats from client, timeout error messages from the RabbitMQ server. This is perfectly normal.

Testing everything together

Before you begin experimenting with the new setup, you need to add the line:

127.0.0.1 host.docker.internal

to the hosts file on your machine. On Linux, you can do this by executing the following command:

$ sudo sh -c 'echo "127.0.0.1 host.docker.internal" >> /etc/hosts'

After you have successfully done this, you can use the following links:

Debtors agent’s “My Currency” webapp

Use this to create new currencies.

Note: You will have to coerce your web browser to trust the self-signed certificate.

Debtors agent’s fake email server

You will need this in order to read the email messages which the debtors agent sends to you, during the user registration and login.

Creditors agent’s “My Wallet” webapp

Use this to obtain already created currencies, trade with them, and make payments with them. By default, the creditors agent is configured to run automated currency exchange sessions every 10 minutes. This is convenient for testing.

Creditors agent’s fake email server

You will need this in order to read the email messages which the creditors agent sends to you, during the user registration and login.

Conclusion

In this post, I explained how one could easily run the full set of Swaptacular network nodes (that is: accounting authority, creditors agent, and debtors agent nodes) on a single computer, for testing and evaluation purposes.