urbit/pub/doc/guide/e-dev.md

Doing development can be a messy process. Since Urbit ships are meant to last forever it can be convenient to development on a disposable ship as to not permanently destroy any of your own part of the urbit network. In this short guide we're going to go over how to set up a fake network for development on a single physical machine.

This guide assumes that you have already followed the setup instructions. Going forward we'll refer to the directory you cloned the repo in as /$URB_DIR.

Start a fake vere for the carrier ~zod.

In /$URB_DIR, run

    $ bin/vere -F -I ~zod -c zod

This will boot vere into the carrier ~zod. Because we're using the flag -F vere doesn't check any of the keys to confirm that we are in fact the owner of ~zod. We use -I here to signal to vere that we want to start an 'imperial' ship, or carrier. -I takes a ship name. You can enter any one of the 256 Urbit carriers. More information on vere and its command line options can be found here.

You should see vere start as usual, although instead of copying its files from a parent ship the files are copied from urb/zod inside your Urbit directory.

For most development tasks, using a fake carrier works really well. You get a very short name, and a safe testing environment. If you need to test out a collection of ships talking to each other, let's keep going.

Start a second fake vere.

In a new terminal, cd to /$URB_DIR and run:

    $ bin/vere -F -c doznec

Since we don't specify a carrier with -I here, this should boot into a submarine, as if you had started vere normally. In your running fake ~zod you should see a ~& alerting you that the sub you just started is your neighbor. This means that a key exchange has happened, and your packets are being transmitted directly. Now, let's get a ticket for a cruiser.

In your fake ~zod, ticket a cruiser:

    ~zod/try=> :ticket ~doznec

This line should return a [ship: ticket] pair of @p. You can Now you can return to your submarine and run:

    ~sipmyl-wolmeb-haswel-losmyl--dibten-holdyn-dacdyn-natsep/try=> :begin

Use the [ship: ticket] pair you got from your fake ~zod to complete the :begin process for ~doznec. When finished you should see something like ; ~doznec _doz_ is your neighbor on your fake ~zod.

You can repeat this process on ~doznec, ticketing destroyers that are children of ~doznec by running :ticket with a valid destroyer. :ticket actually takes two arguments, a ship name and a number indicating how many tickets to generate. ~tasfyn-partyv is the first destroyer under ~doznec, so you can run :ticket ~tasfyn-partyv 5 to get five [ship: ticket] pairs.

Add some files, make sure the network if functioning.

You should now have a directory /$URB_DIR/zod.

In

/$URB_DIR/zod/zod/try/test.txt

Put

    hello from mars

You should see a sync event on ~zod indicated by a + with the file path, and at least one %merge-fine messages on ~doznec. On your filesystem, you should see the file mirrored in /$URB_DIR/doznec/doznec/try/test.txt.

You can also send a few :hi messages over the network. On ~doznec try:

    ~doznec/try=> :hi ~zod "just checking in from urth"

You should see the message appear on your ~zod and get a hi ~zod successful on your ~doznec.

This is a good way to set up a test environment where you can try anything out and break anything you want. When working in these test environments it is usually safest to keep your working files outside of your pier and copy them in. This way you can quickly rm -rf zod/ && bin/vere -F -I ~zod -c zod to start again.