Dockerfile 추가, CD Workflow 추가 #1

	name: Push Dev Image to GitHub Packages on Pushes to Main

	# when tagging action success
	on:
	pull_request:
	types:
	- closed
	branches:
	- main

	jobs:
	if_merged:
	if: github.event.pull_request.merged == true
	name: Build and Push
	runs-on: ubuntu-latest

	steps:
	- name: Checkout
	uses: actions/checkout@v3
	with:
	fetch-depth: 0

	- name: Set up Docker Buildx
	uses: docker/setup-buildx-action@v3

	- name: Cache Docker layers
	uses: actions/cache@v3
	with:
	path: /tmp/.buildx-cache
	key: ${{ runner.os }}-buildx-${{ github.sha }}
	restore-keys: \|
	${{ runner.os }}-buildx-

	- name: Log in to GitHub Packages
	run: echo ${{ secrets.GITHUB_TOKEN }} \| docker login ghcr.io -u USERNAME --password-stdin

	- name: Build Image and Push to GitHub Packages
	id: build_image_and_push
	uses: docker/build-push-action@v5
	env:
	IMAGE_TAG: dev
	with:
	push: true
	tags: \|
	"ghcr.io/NewWays-TechForImpactKAIST/backend:${{ env.IMAGE_TAG }}"
	cache-from: type=local,src=/tmp/.buildx-cache
	cache-to: type=local,dest=/tmp/.buildx-cache-new

	- name: Remove old cache
	run: \|
	rm -rf /tmp/.buildx-cache
	mv /tmp/.buildx-cache-new /tmp/.buildx-cache

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