Nimbus: an Ethereum 2.0 Sharding Client for Resource-Restricted Devices

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Rationale

Nimbus: an Ethereum 2.0 Sharding Client. The code in this repository is currently focusing on Ethereum 1.0 feature parity, while all 2.0 research and development is happening in parallel in nim-beacon-chain. The two repositories are expected to merge in Q1 2019.

Development Updates

To keep up to date with changes and development progress, follow the Nimbus blog.

Building & Testing

Prerequisites

• A recent version of Facebook's RocksDB

  • Compile from source or use the package manager of your OS; for example, Debian, Ubuntu, and Fedora have working RocksDB packages
  • on Windows, you can download pre-compiled DLLs

• GNU make, Bash and the usual POSIX utilities

Obtaining the prerequisites through the Nix package manager

Users of the Nix package manager can install all prerequisites simply by running:

nix-shell nimbus.nix

Build & Develop

POSIX-compatible OS

To build Nimbus (in "build/nimbus"), just execute:

make

Running ./build/nimbus --help will provide you with a list of the available command-line options. To start syncing with mainnet, just execute ./build/nimbus without any parameters.

To execute all tests:

make test

To pull the latest changes in all the Git repositories involved:

git pull
make update

To run a command that might use binaries from the Status Nim fork:

./env.sh vim

Our Wiki provides additional helpful information for debugging individual test cases and for pairing Nimbus with a locally running copy of Geth.

Windows

Install Mingw-w64 for your architecture using the "MinGW-W64 Online Installer" (first link under the directory listing). Run it and select your architecture in the setup menu ("i686" on 32-bit, "x86_64" on 64-bit), set the threads to "win32" and the exceptions to "dwarf" on 32-bit and "seh" on 64-bit. Change the installation directory to "C:\mingw-w64" and add it to your system PATH in "My Computer"/"This PC" -> Properties -> Advanced system settings -> Environment Variables -> Path -> Edit -> New -> C:\mingw-w64\mingw64\bin (it's "C:\mingw-w64\mingw32\bin" on 32-bit)

Install Git for Windows and use a "Git Bash" shell to clone and build Nimbus.

If you don't want to compile RocksDB and SQLite separately, you can fetch pre-compiled DLLs with:

mingw32-make fetch-dlls

This will place the right DLLs for your architecture in the "build/" directory.

You can now follow those instructions in the previous section by replacing make with mingw32-make (regardless of your 32-bit or 64-bit architecture).

Development tips

• you can switch the DB backend with a Nim compiler define: -d:nimbus_db_backend=... where the (case-insensitive) value is one of "rocksdb" (the default), "sqlite", "lmdb"

• the Premix debugging tools are documented separately

• you can control the Makefile's verbosity with the V variable (defaults to 1):

make V=0 # quiet
make V=2 test # more verbose than usual

Git submodule workflow

Working on a dependency:

cd vendor/nim-chronicles
git checkout -b mybranch
# make some changes
git status
git commit -a
git push origin mybranch
# create a GitHub PR and wait for it to be approved and merged
git checkout master
git pull
git branch -d mybranch
# realise that the merge was done without "--no-ff"
git branch -D mybranch
# update the submodule's commit in the superproject
cd ../..
git status
git add vendor/nim-chronicles
git commit

It's important that you only update the submodule commit after it's available upstream.

You might want to do this on a new branch of the superproject, so you can make a GitHub PR for it and see the CI test results.

Don't update all Git submodules at once, just because you found the relevant Git command or make target. You risk updating submodules to other people's latest commits when they are not ready to be used in the superproject.

Adding the submodule "https://github.com/status-im/foo" to "vendor/foo":

./add_submodule.sh status-im/foo

Removing the submodule "vendor/bar":

git submodule deinit -f -- vendor/bar
git rm -f vendor/bar

Checking out older commits, either to bisect something or to reproduce an older build:

git checkout <commit hash here>
make -j8 clean update

Running a dependency's test suite using nim instead of nimble (which cannot be convinced not to run a dependency check, thus clashing with our jury-rigged "vendor/.nimble/pkgs"):

cd vendor/nim-blscurve
../../nimble.sh test

Troubleshooting

Report any errors you encounter, please, if not already documented!

Sometimes, the build will fail even though the latest CI is green - here are a few tips to handle this:

Using the Makefile

• Turn it off and on again:

make clean update

Using Nimble directly

• Wrong Nim version
  • We depend on many bleeding-edge features - Nim regressions often happen
  • Use the Status fork of Nim
• Wrong versions of dependencies
  • nimble dependency tracking often breaks due to its global registry
  • wipe the nimble folder and try again
• C compile or link fails
  • Nim compile cache is pretty buggy and sometimes will fail to recompile
  • wipe your nimcache folder

License

Licensed and distributed under either of

• MIT license: LICENSE-MIT or http://opensource.org/licenses/MIT

or

• Apache License, Version 2.0, (LICENSE-APACHEv2 or http://www.apache.org/licenses/LICENSE-2.0)

at your option. These files may not be copied, modified, or distributed except according to those terms.