SetMatrix GitHub Action

Dynamically generate a matrix JSON for GitHub Actions matrix strategy. Accepts comma-separated values, JSON arrays, JSON files, with filtering and include/exclude support.

Inputs

Input	Required	Default	Description
values	No	—	Comma-separated values OR JSON array
json	No	—	JSON array of objects for complex matrices
file	No	—	Path to a JSON file with the matrix array
name	No	value	Key name when using values input
filter	No	—	Filter expression (e.g. os!=windows, node>=18)
include	No	[]	JSON array of additional combinations
exclude	No	[]	JSON array of combinations to remove

Outputs

Output	Description
matrix	JSON object ready for fromJSON() in matrix strategy
length	Number of matrix combinations
is_empty	true if matrix has zero combinations

Examples

Simple list

jobs:
  setup:
    runs-on: ubuntu-latest
    outputs:
      matrix: ${{ steps.matrix.outputs.matrix }}
    steps:
      - id: matrix
        uses: skgandikota/SetMatrix@v1
        with:
          values: "ubuntu-latest,macos-latest,windows-latest"
          name: "os"

  build:
    needs: setup
    strategy:
      matrix: ${{ fromJSON(needs.setup.outputs.matrix) }}
    runs-on: ${{ matrix.os }}
    steps:
      - run: echo "Building on ${{ matrix.os }}"

Complex multi-dimension matrix

- id: matrix
  uses: skgandikota/SetMatrix@v1
  with:
    json: '[{"os":"ubuntu-latest","node":"18"},{"os":"ubuntu-latest","node":"20"},{"os":"macos-latest","node":"20"}]'
    exclude: '[{"os":"ubuntu-latest","node":"18"}]'

Dynamic matrix from API

- name: Get environments
  id: api
  uses: skgandikota/FetchUrl@v2
  with:
    url: "https://api.example.com/environments"

- name: Build matrix
  id: matrix
  uses: skgandikota/SetMatrix@v1
  with:
    json: "${{ steps.api.outputs.body }}"
    filter: "status==active"

From file

- uses: actions/checkout@v4
- id: matrix
  uses: skgandikota/SetMatrix@v1
  with:
    file: ".github/matrix.json"

License

MIT