[Technical Design][Draft] Bazel for Provisioning

[MuhammedIrfan]

Introduction

Bazel is an open-source build and test tool that scalably supports multi-language and multi-platform projects. it speeds up tests and builds by rebuilding only necessary parts, it is also scalable and can be extended with additional features to suit different needs. At present icon bridge primarily rely on bash scripts to perform task automation such as building and deploying smart contracts, It is unreliable and difficult to manage.

Terminology

Term	Definition	Link

Considerations

Though Bazel is used primarily for build and testing, Its dependency mapping, modularity, and hermetic nature makes it a good candidate to be used for provision, The NEAR integration in hugobyte/feature/bazel branch utilizes Bazel for provisioning

Design

Project Structure

• bridge: Contains rules that basically create a bridge between given two chains, It primarily contains a macro that will expand to the provided rules of the chain.

load("@btp//bridge:defs.bzl", "bridge")

bridge(
    name = "icon_to_near",
    SRC = "icon",
    DST = "near"
)

bridge(
    name = "near_to_icon",
    SRC = "near",
    DST = "icon"
)

• chain_repositories: Here we would define where to find local repositories

def chain_repositories():
    native.local_repository(
        name = "near",
        path = "./rust/near",
    )

    native.local_repository(
        name = "icon",
        path = "./javascore/icon",
    )

• cmd/iconbridge: This contains rules for building iconbridge and container image.
• cmd/iconvalidators: This contains rules for building iconvalidators.
• javascore/icon: This is being declared as a workspace so that we will be able to access rules in this folder using @icon notation, contains rules for local icon node as well as provides certain rules for bridge configuration.
• javascore/icon/cli: The rules performs the utilities of a cli ie deploying smart contracts, adding links and services etc.
• javascore/icon/cli/configs: To Add private keys and key secrets, and is ignored from vcs.
• patches: Some patches that will be applied while building the packages.
• rust/near: This is being declared as a workspace so that we will be able to access rules in this folder using @near notation, contains rules for local near node as well as provides certain rules for bridge configuration.
• rust/neat/cli: The rules performs the utilities of a cli ie deploying smart contracts, adding links and services etc.
• rust/near/cli/configs: To Add private keys and key secrets, and is ignored from vcs.
• utils: Utility scripts such as wait until, to check open port etc.

Pre requisites

• jq
• bazel or bazelisk
• gradle¹

Usage

Bridge can be deployed using the following commands.

1. Build iconbridge container image
   bazel run @btp//cmd/iconbridge:iconbridge_image --incompatible_enable_cc_toolchain_resolution --extra_toolchains @zig_sdk//:linux_amd64_gnu.2.19_toolchain
2. At present the bridge is uni directional,

• To run ICON(lisbon) to NEAR(testnet)
  bazel run @btp//bridge:icon_to_near --define near_network=testnet --define icon_network=lisbon
• To run NEAR(testnet) to ICON(lisbon)
  bazel run @btp//bridge:near_to_icon --define near_network=testnet --define icon_network=lisbon

The above rules will build, deploy, and setup the bridge.

Conclusion

With Bazel,

• We need not install toolchains such as rust as Bazel manages it within.
• Bazel can be integrated well with CI/CDs.
• Run tests in an optimized manner.
• Combining Bazel with aspect and tilt might improve integration better.

¹ This is a workaround done due to the limitation of the optimizedJar grade plugin, We need to migrate that to use bazel to build natively in bazel avoiding the gradle