Fly Secrets not populated during build

15

I just wanted to say this was the key to an afternoon-long unsticking for getting Font Awesome Pro into my build step, with my setup as…

GitHub repo secrets > GitHub Actions > flyctl-actions > Dockerfile

…and looked like this…

workflow.yml

on:
  workflow_dispatch:
env:
  FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}
jobs:
  deploy:
    name: Deploy app
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v2

      - name: Deploy to Fly
        uses: superfly/flyctl-actions@1.1
        with:
          args: "deploy --app ${{ secrets.STAGING_APP_NAME }}
          --build-arg FONT_AWESOME_TOKEN=${{ secrets.FA_TOKEN }}"

.npmrc

@fortawesome:registry=https://npm.fontawesome.com/
//npm.fontawesome.com/:_authToken=${FONT_AWESOME_TOKEN}

Dockerfile

FROM hexpm/elixir:1.10.3-erlang-23.2.7-alpine-3.14.0 AS build
ARG FONT_AWESOME_TOKEN
ENV FONT_AWESOME_TOKEN=${FONT_AWESOME_TOKEN}

[... other things...]

RUN npm run --prefix ./assets build