dispatch.md

github/dispatch.nu

Nushell script for triggering GitHub Actions workflows based on configurable rules.

Requirements

• Nushell (installed and in PATH)
• GitHub CLI (gh) authenticated
• GitHub Token (required for cross-repository operations)
  Note: Automatic github.token doesn't support operations on other repositories!

---

Usage

dispatch.nu [flags]

Flags

Short	Long	Description	Default
-c	--config	Path to dispatch config	.github/.dispatch.yaml
-i	--inputs	Inputs as record or JSON	{}
-h	--help	Show help message

---

Configuration

dispatch.yaml Structure

default:
  dispatch:
    workflow: test-pr.yaml
    inputs:
      client: hello
      feature: pr
    match:
      type: pull_request
      pull_request:
        title_regex: '^ci\({feature} {client}\):'

dispatch:
  - repository: dennybaa/ghbar
  - repository: dennybaa/ghfoo
  - repository: dennybaa/testing
    inputs:
      pr-number: '{pull_request.number}' # additional input (take data from a matched pull_request)
    match:
      fallback_ref: main

Operation Flow

1. Config Loading

   • Reads --config file (default: .github/.dispatch.yaml)
   • Merges configurations with priority:
     default.dispatch < dispatch[N] < --inputs

2. Rule Processing

   • Executes matcher based on match.type
   • Substitutes inputs from parameters ({parameter}) used in rules such as pull_request.title_regex

3. Workflow Dispatch

   • Triggers workflow for each matched ref (branch/tag)

---

GitHub Action Integration

Example Workflow

steps:
  - uses: hustcer/setup-nu@main
  
  - name: Checkout Code
    uses: actions/checkout@v4
    with: { path: code }

  - name: Checkout Nu Modules
    uses: actions/checkout@v4
    with:
      repository: bitdeps/nu_scripts
      path: nu

  - name: Dispatch Workflows
    env:
      GITHUB_TOKEN: ${{ secrets.MYPAT }}
      NU_LOG_LEVEL: info
      NU_MODULE_DIRS: |
        ${{ github.workspace }}/nu/modules;
    shell: nu {0}
    run: |
      const workspace = '${{ github.workspace }}'
      source $"($workspace)/nu/scripts/common/env.nu"
      
      cd code; nu -I (nu-include-dirs) $"($workspace)/nu/scripts/github/dispatch.nu"

Key Environment Variables

• GITHUB_TOKEN: PAT with workflow scope
• NU_MODULE_DIRS: Paths to Nushell modules
• NU_LOG_LEVEL: Script verbosity (debug, info, warning, error)

---

Pattern Matching

• Uses {parameter} placeholders in regex patterns
• Automatically substitutes values from inputs
• Example: '^ci\({feature} {client-id}\):' becomes '^ci\(pr hello\):'