quick-start.md

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Quick Start

Overview

This is a quick start guide. If you have a vague idea about how Tendermint works and want to get started right away, continue.

Install

Quick Install

To quickly get Tendermint installed on a fresh Ubuntu 16.04 machine, use this script.

⚠️ Do not copy scripts to run on your machine without knowing what they do.

curl -L https://git.io/fFfOR | bash
source ~/.profile

The script is also used to facilitate cluster deployment below.

Manual Install

For manual installation, see the install instructions

Initialization

Running:

tendermint init

will create the required files for a single, local node.

These files are found in $HOME/.tendermint:

$ ls $HOME/.tendermint

config  data

$ ls $HOME/.tendermint/config/

config.toml  genesis.json  node_key.json  priv_validator.json

For a single, local node, no further configuration is required. Configuring a cluster is covered further below.

Local Node

Start Tendermint with a simple in-process application:

tendermint node --proxy_app=kvstore

Note: kvstore is a non persistent app, if you would like to run an application with persistence run --proxy_app=persistent_kvstore

and blocks will start to stream in:

I[01-06|01:45:15.592] Executed block                               module=state height=1 validTxs=0 invalidTxs=0
I[01-06|01:45:15.624] Committed state                              module=state height=1 txs=0 appHash=

Check the status with:

curl -s localhost:26657/status

Sending Transactions

With the KVstore app running, we can send transactions:

curl -s 'localhost:26657/broadcast_tx_commit?tx="abcd"'

and check that it worked with:

curl -s 'localhost:26657/abci_query?data="abcd"'

We can send transactions with a key and value too:

curl -s 'localhost:26657/broadcast_tx_commit?tx="name=satoshi"'

and query the key:

curl -s 'localhost:26657/abci_query?data="name"'

where the value is returned in hex.

Cluster of Nodes

First create four Ubuntu cloud machines. The following was tested on Digital Ocean Ubuntu 16.04 x64 (3GB/1CPU, 20GB SSD). We'll refer to their respective IP addresses below as IP1, IP2, IP3, IP4.

Then, ssh into each machine, and execute this script:

curl -L https://git.io/fFfOR | bash
source ~/.profile

This will install go and other dependencies, get the Tendermint source code, then compile the tendermint binary.

Next, use the tendermint testnet command to create four directories of config files (found in ./mytestnet) and copy each directory to the relevant machine in the cloud, so that each machine has $HOME/mytestnet/node[0-3] directory.

Before you can start the network, you'll need peers identifiers (IPs are not enough and can change). We'll refer to them as ID1, ID2, ID3, ID4.

tendermint show_node_id --home ./mytestnet/node0
tendermint show_node_id --home ./mytestnet/node1
tendermint show_node_id --home ./mytestnet/node2
tendermint show_node_id --home ./mytestnet/node3

Finally, from each machine, run:

tendermint node --home ./mytestnet/node0 --proxy_app=kvstore --p2p.persistent_peers="ID1@IP1:26656,ID2@IP2:26656,ID3@IP3:26656,ID4@IP4:26656"
tendermint node --home ./mytestnet/node1 --proxy_app=kvstore --p2p.persistent_peers="ID1@IP1:26656,ID2@IP2:26656,ID3@IP3:26656,ID4@IP4:26656"
tendermint node --home ./mytestnet/node2 --proxy_app=kvstore --p2p.persistent_peers="ID1@IP1:26656,ID2@IP2:26656,ID3@IP3:26656,ID4@IP4:26656"
tendermint node --home ./mytestnet/node3 --proxy_app=kvstore --p2p.persistent_peers="ID1@IP1:26656,ID2@IP2:26656,ID3@IP3:26656,ID4@IP4:26656"

Note that after the third node is started, blocks will start to stream in because >2/3 of validators (defined in the genesis.json) have come online. Persistent peers can also be specified in the config.toml. See here for more information about configuration options.

Transactions can then be sent as covered in the single, local node example above.