[FIX] Avoid NullpointerException thrown during scheduling. #185

	name: Build SPipes engine docker
	on:
	push:
	branches: [ main ]
	workflow_dispatch:
	env:
	IMAGE_NAME: s-pipes-engine
	USERNAME: ${{ github.actor }}
	TOKEN: ${{ secrets.GITHUB_TOKEN }}
	jobs:
	build-and-publish:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2

	- name: Log into registry
	run: echo "${{ secrets.GITHUB_TOKEN }}" \| docker login docker.pkg.github.com -u ${{ github.actor }} --password-stdin

	- name: Build image
	run: \|
	cd aircraft-maintenance-planning-model
	docker build . --file ./Dockerfile --tag $IMAGE_NAME

	- name: Push image
	run: \|
	IMAGE_ID=docker.pkg.github.com/${{ github.repository }}/$IMAGE_NAME
	# Change all uppercase to lowercase
	IMAGE_ID=$(echo $IMAGE_ID \| tr '[A-Z]' '[a-z]')
	# Strip git ref prefix from version
	VERSION=$(echo "${{ github.ref }}" \| sed -e 's,./$.$,\1,')
	# Strip "v" prefix from tag name
	[[ "${{ github.ref }}" == "refs/tags/"* ]] && VERSION=$(echo $VERSION \| sed -e 's/^v//')
	# Use Docker `latest` tag convention
	[ "$VERSION" == "main" ] && VERSION=latest
	echo IMAGE_ID=$IMAGE_ID
	echo VERSION=$VERSION
	docker tag $IMAGE_NAME $IMAGE_ID:$VERSION
	docker push $IMAGE_ID:$VERSION

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