Introduction¶

Building reliable blockchain infrastructure is a notoriously hard problem. As a result, most blockchain companies don’t run their own infrastructure, instead choosing to outsource it to a third-party. chaind makes deploying your own infrastructure simpler and cheaper by acting as a proxy between the Internet and your blockchain nodes. Out of the box, chaind provides the following features:

Automatic failover to any blockchain node with an open RPC endpoint
Intelligent request caching that takes chain reorgs into account
RPC-aware request logging

Getting started¶

The simplest way to get started with chaind is to install one of our pre-built packages using your OS’s package manager. For more information, head on over to Installation and Configuration.

History of `chaind`¶

chaind began in late 2018 as as an internal project at Kyokan. Since then, chaind has served millions of RPC request on low-cost hardware.

Installation¶

From Package¶

The fastest way to install chaind is to install it via your OS’s package manager. We currently have Debian packages available, with RPMs coming soon. To install from our Debian repository, follow these steps:

1. Add Kyokan’s signing key

First, you’ll need to instruct your package manager to trust Kyokan’s PGP key. Our PGP key is stored on MIT’s keyserver, and has the fingerprint A27E D5CE 49FA EB7D E0AA 50D4 23D7 FC00 2105 25.

You’ll only need to perform this step once per machine. Run the command below to use our key:

sudo apt-key adv --keyserver pgp.mit.edu --recv-keys 21052518

You should receive output that looks like this:

Executing: /tmp/apt-key-gpghome.MZuO4hoFiT/gpg.1.sh --keyserver pgp.mit.edu --recv-keys 21052518
gpg: key 23D7FC0021052518: public key "Kyokan, LLC OSS Signing Key <mslipper@kyokan.io>" imported
gpg: Total number processed: 1
gpg:               imported: 1

2. Add Kyokan’s Debian repository to your sources.list

Run the following command to add Kyokan’s Debian repository to your sources.list file:

echo "deb https://dl.bintray.com/kyokan/oss-deb any main" | sudo tee -a /etc/apt/sources.list

This also only needs to be done once per machine.

3. Install chaind

Now you’re ready to install chaind. To do so, run these commands:

sudo apt-get update
sudo apt-get install chaind

From Source¶

To build and install chaind from source, you’ll need to first install the following prerequisites:

go version 1.10 or higher
make
dep
git

Now, get the chaind source by running go get -u github.com/kyokan/chaind and cd into the source directory. You can now build and install chaind with the following commands:

make deps
make build
make install-global

make install-global will place the chaind binary in /usr/bin. You’ll need to create a configuration file manually.

Next Steps¶

Now, you’re ready to configure your chaind instance. See our Configuration page for more information.

Configuration¶

Configuration file¶

chaind is configured via a single chaind.toml file. When you install chaind using a package manager, a default chaind.toml is placed in /etc/chaind. It looks like this:

eth_path = "eth"
rpc_port = 8080
log_level = "info"

[log_auditor]
log_file="/var/log/chaind_audit.log"

[redis]
url="localhost:6379"

[[backend]]
type="ETH"
url="https://mainnet.infura.io/"
name="infura"

[[backend]]
type="ETH"
url="http://localhost:8545/"
name="local"
main=true

The only parts of the config file you’ll need to change are the [[backend]] stanzas, since the default URLs are only examples and won’t work out of the box. These stanzas define which blockchain nodes chaind will be proxying to. There can be an unlimited number of backends. Below, see a description of each available backend configuration directive:

Backend configuration¶

Key	Description
type	The type of blockchain node. Currently, can only be `ETH`, however in the future `BTC` (and potentially others) will be supported.
url	The URL to the blockchain node. Can be `http` or `https`.
name	A name for the backend. Will appear in logs.
main	Optional. Defines whether or not `chaind` should proxy to this node by default. There can only be one `main` backend per `type`. If `main` isn’t specified, the first backend will be chosen as the main.

Server configuration¶

The following directives are used to configure chaind itself:

Key	Description
rpc_port	The port at which to listen for RPC requests.
log_level	`chaind`’s log level. Can be one of the following: `trace`, `debug`, `info`, `warn`, `error`, `crit`.
`[log_auditor]`.log_file	The location of `chaind`’s audit log file
`[redis]`.url	URL to an instance of Redis.