- spin up a cluster of nodes
- copy config files for a tendermint testnet to each node
- copy linux binaries for tendermint and the app to each node
- start tendermint on every node

How it Works

To use, a user must only provide a directory containing two files: bins and run.sh.

The bins file is a list of binaries, for instance:

$GOPATH/bin/tendermint
$GOPATH/bin/dummy

and the run.sh specifies how those binaries ought to be started:

#! /bin/bash

if [[ "$SEEDS" != "" ]]; then
	SEEDS_FLAG="--seeds=$SEEDS"
fi

./dummy --persist .tendermint/data/dummy_data >> app.log 2>&1 &
./tendermint node --log_level=info $SEEDS_FLAG >> tendermint.log 2>&1 &

This let's you specify exactly which versions of Tendermint and the application are to be used, and how they ought to be started.

Note that these binaries MUST be compiled for Linux. If you are not on Linux, you can compile binaries for linux using go build with the GOOS variable:

GOOS=linux go build -o $GOPATH/bin/tendermint-linux $GOPATH/src/github.com/tendermint/tendermint/cmd/tendermint

This cross-compilation must be done for each binary you want to copy over.

If you want to use an application that requires more than just a few binaries, you may need to do more manual work, for instance using terraforce to set up the development environment on every machine.

Dependencies

We use terraform for spinning up the machines, and a custom rolled tool, terraforce, for running commands on many machines in parallel. You can download terraform here: https://www.terraform.io/downloads.html To download terraforce, run go get github.com/ebuchman/terraforce

We use tendermint itself to generate files for a testnet. You can install tendermint with

cd $GOPATH/src/github.com/tendermint/tendermint
glide install
go install ./cmd/tendermint

You also need to set the DIGITALOCEAN_TOKEN environment variables so that terraform can spin up nodes on digital ocean.

This stack is currently some terraform and a bunch of shell scripts, so its helpful to work out of a directory containing everything. Either change directory to $GOPATH/src/github.com/tendermint/tendermint/test/net or make a copy of that directory and change to it. All commands are expected to be executed from there.

For terraform to work, you must first run terraform get

Create

To create a cluster with 4 nodes, run

terraform apply

To use a different number of nodes, change the desired_capacity parameter in the main.tf.

Note that terraform keeps track of the current state of your infrastructure, so if you change the desired_capacity and run terraform apply again, it will add or remove nodes as necessary.

If you think that's amazing, so do we.

To get some info about the cluster, run terraform output.

See the terraform docs for more details.

To tear down the cluster, run terraform destroy.

Initialize

Now that we have a cluster up and running, let's generate the necessary files for a Tendermint node and copy them over. A Tendermint node needs, at the least, a priv_validator.json and a genesis.json. To generate files for the nodes, run

tendermint testnet 4 mytestnet

This will create the directory mytestnet, containing one directory for each of the 4 nodes. Each node directory contains a unique priv_validator.json and a genesis.json, where the genesis.json contains the public keys of all priv_validator.json files.

If you want to add more files to each node for your particular app, you'll have to add them to each of the node directories.

Now we can copy everything over to the cluster. If you are on Linux, run

bash scripts/init.sh 4 mytestnet examples/in-proc

Otherwise (if you are not on Linux), make sure you ran

GOOS=linux go build -o $GOPATH/bin/tendermint-linux $GOPATH/src/github.com/tendermint/tendermint/cmd/tendermint

and now run

bash scripts/init.sh 4 mytestnet examples/in-proc-linux

Start

Finally, to start Tendermint on all the nodes, run

bash scripts/start.sh 4

Check

Query the status of all your nodes:

bash scripts/query.sh 4 status