@brief Describes how to download, compile, and configure an EOS.IO node
The following instructions overview the process of getting the software, building it, and running a simple test network that produces blocks.
### Setting up a build/development environment
This project is written primarily in C++14 and uses CMake as its build system. An up-to-date C++ toolchain (such as Clang or GCC) and the latest version of CMake is recommended. At the time of this writing, Nathan uses clang 4.0.0 and CMake 3.8.0.
### Installing Dependencies
Eos has the following external dependencies, which must be installed on your system:
By default LLVM and clang do not include the WASM build target, so you will have to build it yourself. Note that following these instructions will create a version of LLVM that can only build WASM targets.
If a repo is cloned without the `--recursive` flag, the submodules can be retrieved after the fact by running this command from within the repo:
`git submodule update --init --recursive`
### Configuring and building
To do an in-source build, simply run `cmake .` from the top level directory. Out-of-source builds are also supported. To override clang's default choice in compiler, add these flags to the CMake command:
For a debug build, add `-DCMAKE_BUILD_TYPE=Debug`. Other common build types include `Release` and `RelWithDebInfo`.
After successfully running cmake, simply run `make` to build everything. To run the test suite after building, run the `chain_test` executable in the `tests` folder.
### Using the WASM compiler to perform a full build of the project
The WASM_LLVM_CONFIG environment variable is used to find our recently built WASM compiler.
This is needed to compile the example contracts insde eos/contracts folder and their respective tests.
If you are doing active development on EOS.IO software you may want to add WASM_LLVM_CONFIG to your `.bash_profile`
### Creating and launching a single-node testnet
After successfully building the project, the `eosd` binary should be present in the `programs/eosd` directory. Go ahead and run `eosd` -- it will probably exit with an error, but if not, close it immediately with Ctrl-C. Note that `eosd` will have created a directory named `data-dir` containing the default configuration (`config.ini`) and some other internals. This default data storage path can be overridden by passing `--data-dir /path/to/data` to `eosd`.
Edit the `config.ini` file, adding the following settings to the defaults already in place:
```
# Load the testnet genesis state, which creates some initial block producers with the default key
genesis-json = /path/to/eos/source/genesis.json
# Enable production on a stale chain, since a single-node test chain is pretty much always stale
enable-stale-production = true
# Enable block production with the testnet producers
producer-name = inita
producer-name = initb
producer-name = initc
producer-name = initd
producer-name = inite
producer-name = initf
producer-name = initg
producer-name = inith
producer-name = initi
producer-name = initj
producer-name = initk
producer-name = initl
producer-name = initm
producer-name = initn
producer-name = inito
producer-name = initp
producer-name = initq
producer-name = initr
producer-name = inits
producer-name = initt
producer-name = initu
# Load the block producer plugin, so we can produce blocks
plugin = eos::producer_plugin
```
Now it should be possible to run `eosd` and see it begin producing blocks. At present, the P2P code is not implemented, so only single-node configurations are possible. When the P2P networking is implemented, these instructions will be updated to show how to create an example multi-node testnet.
[Check the latest instructions to build EOS.IO in Github!](https://github.com/EOSIO/eos#building-eos-and-running-a-node)
