create config (only once)
#show state before
gcloud config configurations list
gcloud config configurations create "MY_PROFILE"
export CLOUDSDK_ACTIVE_CONFIG_NAME="MY_PROFILE"
gcloud config set core/project "MY_GCP_PROJECT"
gcloud config set core/account "MY_EMAIL"
#show state after
gcloud config configurations list
use config (every terminal session)
# choose project
export CLOUDSDK_ACTIVE_CONFIG_NAME="MY_PROFILE"
# login (valid for about an hour)
export GOOGLE_OAUTH_ACCESS_TOKEN="$(gcloud auth print-access-token)"