WANChain Go

Branch	Tests
master
develop

Building the source

Building gwan requires both a Go (version 1.7 or later) and a C compiler.

If build release version,Docker is required

You can install them using your favourite package manager. Once the dependencies are installed, run

make gwan

or, to build the full suite of utilities:

make all

or, to build the release version

make release	

Running gwan

Full node on the main wanchain network

By far the most common scenario is people wanting to simply interact with the wanchain network: create accounts; transfer funds; deploy and interact with contracts. For this particular use-case the user doesn't care about years-old historical data, so we can fast-sync quickly to the current state of the network. To do so:

$ gwan console

This command will:

• Start gwan in fast sync mode (default, can be changed with the --syncmode flag), causing it to download more data in exchange for avoiding processing the entire history of the wanchain network, which is very CPU intensive. This too is optional and if you leave it out you can always attach to an already running gwan instance with gwan attach.

Full node on the wanchain test network

Transitioning towards developers, if you'd like to play around with creating wanchain contracts, you almost certainly would like to do that without any real money involved until you get the hang of the entire system. In other words, instead of attaching to the main network, you want to join the test network with your node, which is fully equivalent to the main network, but with play-Ether only.

$ gwan --testnet console

The console subcommand have the exact same meaning as above and they are equally useful on the testnet too. Please see above for their explanations if you've skipped to here.

Specifying the --testnet flag however will reconfigure your gwan instance a bit:

• Instead of using the default data directory (~/.wanchain on Linux for example), gwan will nest itself one level deeper into a testnet subfolder (~/.wanchain/testnet on Linux). Note, on OSX and Linux this also means that attaching to a running testnet node requires the use of a custom endpoint since gwan attach will try to attach to a production node endpoint by default. E.g. gwan attach <datadir>/testnet/gwan.ipc. Windows users are not affected by this.
• Instead of connecting the main wanchain network, the client will connect to the test network, which uses different P2P bootnodes, different network IDs and genesis states.

Note: Although there are some internal protective measures to prevent transactions from crossing over between the main network and test network, you should make sure to always use separate accounts for play-money and real-money. Unless you manually move accounts, gwan will by default correctly separate the two networks and will not make any accounts available between them.

Programatically interfacing gwan nodes

As a developer, sooner rather than later you'll want to start interacting with gwan and the wanchain network via your own programs and not manually through the console. To aid this, gwan has built in support for a JSON-RPC based APIs 。These can be exposed via HTTP, WebSockets and IPC (unix sockets on unix based platforms, and named pipes on Windows).

The IPC interface is enabled by default and exposes all the APIs supported by gwan, whereas the HTTP and WS interfaces need to manually be enabled and only expose a subset of APIs due to security reasons. These can be turned on/off and configured as you'd expect.

HTTP based JSON-RPC API options:

• --rpc Enable the HTTP-RPC server
• --rpcaddr HTTP-RPC server listening interface (default: "localhost")
• --rpcport HTTP-RPC server listening port (default: 8545)
• --rpcapi API's offered over the HTTP-RPC interface (default: "eth,net,web3")
• --rpccorsdomain Comma separated list of domains from which to accept cross origin requests (browser enforced)
• --ws Enable the WS-RPC server
• --wsaddr WS-RPC server listening interface (default: "localhost")
• --wsport WS-RPC server listening port (default: 8546)
• --wsapi API's offered over the WS-RPC interface (default: "eth,net,web3")
• --wsorigins Origins from which to accept websockets requests
• --ipcdisable Disable the IPC-RPC server
• --ipcapi API's offered over the IPC-RPC interface (default: "admin,debug,eth,miner,net,personal,shh,txpool,web3")
• --ipcpath Filename for IPC socket/pipe within the datadir (explicit paths escape it)

You'll need to use your own programming environments' capabilities (libraries, tools, etc) to connect via HTTP, WS or IPC to a gwan node configured with the above flags and you'll need to speak JSON-RPC on all transports. You can reuse the same connection for multiple requests!

Note: Please understand the security implications of opening up an HTTP/WS based transport before doing so! Hackers on the internet are actively trying to subvert wanchain nodes with exposed APIs! Further, all browser tabs can access locally running webservers, so malicious webpages could try to subvert locally available APIs!

Creating the rendezvous point

With all nodes that you want to run initialized to the desired genesis state, you'll need to start a bootstrap node that others can use to find each other in your network and/or over the internet. The clean way is to configure and run a dedicated bootnode:

$ bootnode --genkey=boot.key
$ bootnode --nodekey=boot.key

With the bootnode online, it will display an [enode URL] that other nodes can use to connect to it and exchange peer information. Make sure to replace the displayed IP address information (most probably [::]) with your externally accessible IP to get the actual enode URL.

Note: You could also use a full fledged gwan node as a bootnode, but it's the less recommended way.

Starting up your member nodes

With the bootnode operational and externally reachable (you can try telnet <ip> <port> to ensure it's indeed reachable), start every subsequent gwan node pointed to the bootnode for peer discovery via the --bootnodes flag. It will probably also be desirable to keep the data directory of your private network separated, so do also specify a custom --datadir flag.

$ gwan --datadir=path/to/custom/data/folder --bootnodes=<bootnode-enode-url-from-above>

Note: Since your network will be completely cut off from the main and test networks, you'll also need to configure a miner to process transactions and create new blocks for you.

Docker quick start

One of the quickest ways to get wanchain up and running on your machine is by using Docker:

docker run -d --name wanchain-node -v /home/ubuntu/wanchain:/root \
           -p 8545:8545 -p 17717:17717 \
           wanchain/client-go --rpc

This will start gwan in fast-sync mode with a DB memory allowance of 1GB just as the above command does. It will also create a persistent volume in your home directory for saving your blockchain as well as map the default ports. Do not forget --rpcaddr 0.0.0.0, if you want to access RPC from other containers and/or hosts. By default, gwan binds to the local interface and RPC endpoints is not accessible from the outside.