香港開源區塊鏈活動 Hyperledger BootCamp 2019

3月7-8日Linux基金會在香港數碼港舉行開源區塊鏈活動 Hyperledger BootCamp 2019，為Hyperledger旗下不同開源區塊鏈專案「開坑」，讓新開發者加速了解不同專案的入門方法，速成教導新開發者貢獻專案的程序。

BootCamp形式像BarCamp那像Unconfernce形式，由參加者設定每節題目。而不同之處是每節都需要參加者自備手提電腦，按不同專案和類型，分作12個10人大圓桌小組，跟主持（Session Leader）做一些習作和互動。主持按照該節目的，或多或少指導參加者作業，甚至交由參加者主導作業。另設三間10-20人培訓室，多作入門教學。

源自 IBM 釋出源碼的Hyperledger Fabric自然有不少人棒場，而筆者在兩日活動主要參加Hyperledger Iroha和Hyperledger Indy相關環節。

區塊鏈入門環節The Forest & the Trees! The unifying foundations of Blockchain，為區塊鏈新手講解區塊鏈技術。

以下是筆者英文速記：

• DLT = Distributed Ledger Technology
• Hash and Message Digest
• Public Key Crypto
• Merkle Tree
• Transaction Chain
• Blockchain
  • Header- contains
  • Chaining-achieved through hashing of previous blocks
  • Merkle Root: Hash based data structure of transactions (here Hash of Block data)
• Permissioned vs Permissionless
• Block-Fabric
  • Blockchain
  • Additional items in header and transactions…..
• Block-Sawtooth
  • additional items in header an batches are to do with permission ledgers.

Hyperledger Indy需要懂Rust的開發者，所以設有入門環節Introduction to Rust and Cargo，讓不認識Rust的開發者快速了解這Rust語言。以下是筆者英文速記：

• WASM!!
  • Web app server -> middleware -> browser code, all in RUST!
• cargo init –bin myproject
• Cargo.toml
  • .toml json file in different layout.
• cargo build
• cargo run
  • Finished dev [unoptimized + debuginfo] target(s) in 4.53 secs
• optimised version
  • cargo build —release
  • Finished release [optimized] target(s) in 0.0 secs
• https://doc.rust-lang.org/stable/book/
• https://doc.rust-lang.org/stable/cargo/
• https://doc.rust-lang.org/stable/rust-by-example/
• https://crates.io/
  • More packages than Python, Node
  • Most Recommended Package: serde
    • a generice serialisation/deserialization framework
• IRON extensible web framework for rust
  • ironframework.io
• enum = data type
• pub fn fn_name() {… } = public function
• for i in a {… } = for loop
• let, let out something = 0;
• impl

筆者在Hyperledger Iroha入門環節Getting Started with Iroha Session I 的英文速記。

• Features
  • Command-driven architecture
    • Asset management
    • Identify management
  • Byzantine fault-tolerant ordering service and consensus
  • Role-based access control
  • Mutlo-signature transactions
  • Universal peer role and easy scripted deployment with Docker and Ansible
• Why Iroha
  • Distributed Ledger platform for simple use-cases of payments and identify storage.
  • Uses fixed set of commands 16 in total (eg. asset creation, transfers, account creation) and ?? queues.
• Successful Proof of Concept projects: cross-chain exchange, bank settlements, etc.
• Data structure
  • User account {account_name}@{domain}
  • Each user have some Asset {asset_name}#{domain}
• Works
  • Run Iroha locally
  • Create simple web service to interact with Iroha
• Workshop 1
  • Start Iroha node locally and perform several operations over it using CLI by following Getting Started document
    • https://iroha.readthedocs.io/en/latest/getting_started/
  • Get familiar with client java lib
  • obtain the wireframe example web server
  • implement needed functions by example from client java lib
  • check everything using Postman tool
  • https://www.notion.so/Iroha-for-beginners-Practical-Part-c0983b5c3f1b4812b8ad9913feecb8a2
  • Iroha in Python: https://github.com/hyperledger/iroha-python

irohad –config ~/config.docker –keypair_name ~/node0

[2019-03-07 10:57:01.576692300] [I] [CLI/ResponseHandler/Query]: [Account Assets] [2019-03-07 10:57:01.576748700] [I] [CLI/ResponseHandler/Query]: -Account Id:- test@test [2019-03-07 10:57:01.576762100] [I] [CLI/ResponseHandler/Query]: -Asset Id- coolcoin#test [2019-03-07 10:57:01.576776500] [I] [CLI/ResponseHandler/Query]: -Balance- 100.5

[2019-03-07 10:57:40.420019600] [I] [CLI/ResponseHandler/Query]: [Account Assets] [2019-03-07 10:57:40.420044900] [I] [CLI/ResponseHandler/Query]: -Account Id:- admin@test [2019-03-07 10:57:40.420052900] [I] [CLI/ResponseHandler/Query]: -Asset Id- coolcoin#test [2019-03-07 10:57:40.420063700] [I] [CLI/ResponseHandler/Query]: -Balance- 100.0

筆者在Hyperledger Indy入門環節Getting Started with Indy的英文速記。

• Sovrin Foundation, Sovrin Alliance
• Identity
• Sovrin donate source code to LF.
• Most Bottom Layer: Indy-Crypto -> HyperLedger Ursa
• Client side: Indy-SDK (libIndy & libVCX), Agent (on top SDK) (Python, Node), Sovrin Connector-App
• Ledger side: Indy Plenum (Communicate with Nodes), Indy-Node (on top of Plenum)(Handling Identity), Sovrin Ledger plugin
• Look for: Agent Protocol, Schema2.0, DKMS Efforts (Decentrailised Key Management System), Ledger 2.0 (Python?).

然後是Indy Agent的英文速記。

• https://indyscan.io/
• https://github.com/hyperledger/indy-agent
• 跟Quickstart： https://github.com/hyperledger/indy-agent/tree/master/python
• 使用網卡IP地址而不用localhost
• https://vonx.io/about/
• https://sovrin.org/library/
• https://github.com/streetcred-id

在結束環節最後，Hyperledger團隊宣佈David Liu被選為新的義務宣傳大使(ambassador)。 （原文提供：Router.HK）