test: setup testing environment and reproducible build

.envrc

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+if ! has nix_direnv_version || ! nix_direnv_version 3.0.4; then
+  source_url "https://raw.githubusercontent.com/nix-community/nix-direnv/3.0.4/direnvrc" "sha256-DzlYZ33mWF/Gs8DDeyjr8mnVmQGx7ASYqA5WlxwvBG4="
+fi
+
+watch_file rust-toolchain.toml
+use flake

.gitignore

@@ -16,3 +16,6 @@ target/
 
 # MSVC Windows builds of rustc generate these, which store debugging information
 *.pdb
+
+# reproducible local environment
+.direnv

.taplo.toml

@@ -1,3 +1,5 @@
+exclude = [".direnv/*"]
+
 [[rule]]
 include = ["**/*.toml"]
 

Cargo.toml

@@ -126,7 +126,7 @@ cumulus-pallet-parachain-system = { git = "https://github.com/paritytech/polkado
 cumulus-pallet-session-benchmarking = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-v1.11.0", default-features = false }
 cumulus-pallet-xcm = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-v1.11.0", default-features = false }
 cumulus-pallet-xcmp-queue = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-v1.11.0", default-features = false }
-cumulus-primitives-core = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-v1.11.0", default_features = false }
+cumulus-primitives-core = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-v1.11.0", default-features = false }
 cumulus-primitives-parachain-inherent = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-v1.11.0" }
 cumulus-primitives-storage-weight-reclaim = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-v1.11.0", default-features = false }
 cumulus-primitives-utility = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-v1.11.0", default-features = false }

DEVELOPMENT.md

@@ -0,0 +1,35 @@
+# Development environment for Polka Storage Node 
+
+## Setup
+
+### Requirements
+- [nix](https://nixos.org/download/) with [flakes](https://nixos.wiki/wiki/flakes) enabled (`echo 'experimental-features = nix-command flakes' >> ~/.config/nix/nix.conf`)
+    - reasoning: every developer has the same version of development tools (rust, protoc, zombienet), directed by [flake.nix](./flake.nix)`. 
+    - how it works? fasterthanli.me has [a whole series on it](https://fasterthanli.me/series/building-a-rust-service-with-nix/part-10).
+    - optional: [vscode extension for Nix](https://marketplace.visualstudio.com/items?itemName=jnoortheen.nix-ide)
+- [direnv](https://direnv.net/) with a [shell hook](https://direnv.net/docs/hook.html)
+    - *VS Code only* [direnv extension](https://marketplace.visualstudio.com/items?itemName=mkhl.direnv) (uses the same tooling as rust-toolchain.toml defined).
+    - reasoning: when you enter a directory it uses everything defined in [.envrc](./.envrc), e.g. environment variables, `nix`, secrets.
+
+## Usage
+
+0. [Optional, if you don't have `direnv`] `nix develop`
+1. Verify:
+```
+$ polkadot --version
+polkadot 1.11.0-0bb6249
+
+$ cargo --version
+cargo 1.77.0 (3fe68eabf 2024-02-29)
+
+$ zombienet version
+1.3.103
+```
+2. `just testnet`
+3. Get into a direct link of `charlie` node to access parachain interface and see block production (it takes ~30s).
+    - testnet is defined via [zombienet configuration](https://paritytech.github.io/zombienet/guide.html) in [local-testnet.toml](./scripts//local-testnet.toml)
+
+## Maintenance
+
+- Updating nix flakes (`flake.lock` file has frozen state of package): `nix flake update`.
+- Running out of the disk space? `nix-collect-garbage`.

Justfile

@@ -0,0 +1,15 @@
+alias b := build
+alias r := release
+alias t := testnet
+
+lint:
+    taplo lint && taplo fmt --check
+
+build: lint
+    cargo build
+
+release: lint
+    cargo build --release
+
+testnet: release
+    zombienet -p native spawn scripts/local-testnet.toml

flake.nix

@@ -0,0 +1,54 @@
+{
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+    rust-overlay = {
+      url = "github:oxalica/rust-overlay";
+      inputs = {
+        nixpkgs.follows = "nixpkgs";
+        flake-utils.follows = "flake-utils";
+      };
+    };
+    zombienet = {
+      url = "github:paritytech/zombienet";
+      inputs = {
+        nixpkgs.follows = "nixpkgs";
+      };
+    };
+  };
+  outputs = { self, nixpkgs, flake-utils, rust-overlay, zombienet }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        overlays = [ (import rust-overlay) zombienet.overlays.default ];
+        pkgs = import nixpkgs {
+          inherit system overlays;
+        };
+        rustToolchain = pkgs.pkgsBuildHost.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
+        buildInputs = with pkgs; [
+          clang
+          pkg-config
+          rustToolchain
+          just
+          taplo
+          polkadot
+          # Due to zombienet's flake.nix, needs to be prefixed with pkg.zombienet
+          pkgs.zombienet.default
+        ] ++ lib.optionals stdenv.isDarwin [
+          darwin.apple_sdk.frameworks.Security
+          darwin.apple_sdk.frameworks.CoreServices
+          darwin.apple_sdk.frameworks.SystemConfiguration
+        ];
+      in
+      with pkgs;
+      {
+        devShells.default = mkShell {
+          inherit buildInputs;
+
+          LIBCLANG_PATH = "${llvmPackages.libclang.lib}/lib";
+          PROTOC = "${protobuf}/bin/protoc";
+          RUST_SRC_PATH = "${rustToolchain}/lib/rustlib/src/rust/library/";
+          ROCKSDB_LIB_DIR = "${rocksdb}/lib";
+        };
+      }
+    );
+}

rust-toolchain.toml

@@ -0,0 +1,5 @@
+[toolchain]
+channel = "1.77.0"
+components = ["cargo", "clippy", "rust-analyzer", "rust-src", "rust-std", "rustc", "rustc-dev", "rustfmt"]
+profile = "minimal"
+targets = ["wasm32-unknown-unknown"]

scripts/local-testnet.toml

@@ -0,0 +1,21 @@
+[relaychain]
+chain = "rococo-local"
+default_command = "polkadot"
+
+[[relaychain.nodes]]
+name = "alice"
+validator = true
+
+[[relaychain.nodes]]
+name = "bob"
+validator = true
+
+[[parachains]]
+cumulus_based = true
+id = 2000
+
+# run charlie as parachain collator
+[[parachains.collators]]
+command = "target/release/polka-storage-node"
+name = "charlie"
+validator = true