GitHub Action workflow not being interpreted upon merge - continuous-integration

Question

I'm attempting to create a GHA workflow and I am getting an error that I'm unsure how to fix as I've implemented this in similar environments before.
name: Deploy Staging
# Controls when the workflow will run
on:
# Triggers the workflow on push events only for the main branch
push:
branches: [ main ]
# Allows you to run this workflow manually from the Actions tab
workflow_dispatch:
jobs:
# Run the build job first
build:
name: Build
uses: ./.github/workflows/build.yml
deploy-staging:
name: Staging Deploy
runs-on: ubuntu-latest
environment:
name: staging
needs: [build]
permissions:
id-token: write
contents: read
steps:
- uses: actions/setup-node#v3
with:
node-version: '14'
- name: Download build artifacts
uses: actions/download-artifact#v3
with:
name: buildResult
- name: CDK install
run: npm install -g aws-cdk
- name: Configure AWS credentials
uses: aws-actions/configure-aws-credentials#v1
with:
role-to-assume: XXXX
aws-region: us-east-1
- name: CDK diff
run: cdk --app . diff staging
- name: CDK deploy
run: cdk --app . deploy staging --require-approval never
- name: Configure DX AWS credentials
uses: aws-actions/configure-aws-credentials#v1
with:
role-to-assume: XXXX
aws-region: us-east-1
role-session-name: "${{ github.actor }}"
- name: Report deployment
uses: XXXX/deployment-tracker-action#v1
if: always()
with:
application-name: XXXX
environment: staging
platform: test
deployment-status: ${{ steps.deploy-workload.outcome == 'success' && 'success' || 'fail' }}
aws-region: us-east-1
XXXX
I don't understand quite where I'm going wrong here but when I merged my actions branch and I attempted to get it to work, I received the following message:
error parsing called workflow "./.github/workflows/build.yml": workflow is not reusable as it is missing a `on.workflow_call` trigger
Below is my build file for reference.
name: Build
# Controls when the workflow will run
on:
pull_request:
branches: [ main ]
# Allows you to run this workflow manually from the Actions tab
workflow_dispatch:
inputs:
buildEnvironment:
description: Build Environment
required: false
default: production
# A workflow run is made up of one or more jobs that can run sequentially or in parallel
jobs:
# next build runs lint, don't need a step for it
build:
name: Build
runs-on: ubuntu-latest
permissions:
id-token: write
contents: read
steps:
- uses: actions/checkout#v3
- uses: actions/setup-node#v3
with:
node-version: '14'
- name: Configure AWS Credentials
uses: aws-actions/configure-aws-credentials#v1
with:
role-to-assume: XXXX
aws-region: us-east-1
role-session-name: "${{ github.actor }}"
- name: Install Dependencies
run: npm install
- name: CDK install
run: npm install -g aws-cdk
- name: CDK build
run: cdk synth
- name: Upload build artifacts
uses: actions/upload-artifact#v3
with:
name: buildResult
path: |
cdk.out
test:
name: Test
runs-on: ubuntu-latest
permissions:
id-token: write
contents: read
steps:
# Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
- uses: actions/checkout#v3
- uses: actions/setup-node#v3
with:
node-version: '14'
- name: Configure AWS Credentials
uses: aws-actions/configure-aws-credentials#v1
with:
role-to-assume: XXXX
aws-region: us-east-1
role-session-name: "${{ github.actor }}"
- name: Install Dependencies
run: npm install
- name: Run tests
run: npm test

Answer 1

If you want to call another workflow (reusable workflow), the workflow you're calling needs to have the trigger workflow_call.
Therefore, in order to resolve your error, change build.yml to:
name: Build
on:
workflow_call:
pull_request:
# etc..