nix-bitcoin/dev/README.md

This directory contains docs and helper scripts for developing and debugging:

• dev.sh: misc dev helpers
• dev-features.sh: helpers for developing specific nix-bitcoin features, like services
• topics features specific topics
• dev-scenarios.nix: extra test scenarios used in the above scripts

See also: test/README.md

Run a dev shell

There are two ways to run a dev shell:

1. Run command nix develop

This starts a shell with test/run-tests.sh and the scripts in dir helper added to PATH.

2. Setup and start the direnv dev env

This is an opinionated, direnv-based dev env, optimized for developer experience.

dev-env/create.sh creates a git repo with the following contents:

• Dir src which contains the nix-bitcoin repo
• Dir bin for helper scripts
• File scenarios.nix for custom test scenarios
• File .envrc that defines a direnv environment, mainly for adding nix-bitcoin and helper scripts to PATH

Installation

1. Install direnv.
   If you use NixOS (and Bash as the default shell), just add the following to your system config:

     environment.systemPackages = [ pkgs.direnv ];
     programs.bash.interactiveShellInit = ''
       eval "$(direnv hook bash)"
     '';
   

2. Create the dev env:

   # Set up a dev environment in dir ~/dev/nix-bitcoin.
   # The dir is created automatically.
   ./dev-env/create.sh ~/dev/nix-bitcoin
   
   cd ~/dev/nix-bitcoin
   
   # Enable direnv
   direnv allow
   

3. Optional: Editor integration

   • Add envrc support to your editor
   • Setup your editor so you can easily execute lines or paragraphs from a shell script file in a shell.
     This simplifies using dev helper scripts like ./dev.sh.

Explore the dev env

# The direnv is automatically activated when visiting any subdir of ~/dev/nix-bitcoin
cd ~/dev/nix-bitcoin

ls -al . bin lib

# The direnv config file
cat .envrc

# You can use this file to define extra scenarios
cat scenarios.nix

# Binary `dev-run-tests` runs nix-bitcoin's `run-tests.sh` with extra scenarios from ./scenarios.nix
# Example:
# Run command `nodeinfo` in `myscenario` (defined in ./scenarios.nix) via a container
dev-run-tests -s myscenario container --run c nodeinfo

# Equivalent (shorthand)
te -s myscenario container --run c nodeinfo

# Run the tests for `myscenario` in a VM
te -s myscenario

# Start an interactive shell inside a VM
te -s myscenario vm

See also: test/README.md

Adding a new service

It's easiest to use an existing service as a template:

• electrs.nix: a basic service
• clightning.nix: simple, but covers a few more features.
  (A cli binary and a runtime-composed config to include secrets.)
• rtl.nix: includes a custom package, defined in pkgs/rtl.
  Most other services use packages that are already included in nixpkgs.

Switching to a new NixOS release

• flake.nix: update nixpkgs.url
• cirrus.yml: update toplevel container -> image attribute
• examples/configuration.nix: update system.stateVersion
• Treewide: check if any TODO-EXTERNAL comments can be resolved