https://flask.palletsprojects.com/en/1.1.x/quickstart/#a-minimal-application
https://codelabs.developers.dockerrgoogle.com/codelabs/cloud-run-hello-python3
gcloud services enable cloudbuild.googleapis.com run.googleapis.com
``` bash
PROJECT_ID=$(gcloud config get-value project)
echo $PROJECT_ID
DOCKER_IMG="gcr.io/$PROJECT_ID/project"
echo $DOCKER_IMG
gcloud builds submit --tag $DOCKER_IMG
gcloud beta emulators firestore start --host-port "localhost:8001"