Show the schema loaded by the app contained in the specified docker image

schema-for.sh

#!/bin/bash

function cleanup () {
    docker rm -f $pg >/dev/null
}

trap cleanup EXIT

PARAMS=""
while (( "$#" )); do
    case "$1" in
        --pg-version)
            PGVERSION=$2
            shift 2
            ;;
        -b|--schema-builders)
            SCHEMA_BUILDERS=$2
            shift 2
            ;;
        -i|--image)
            IMAGE=$2
            shift 2
            ;;
        -d|--dbname)
            PGDATABASE=$2
            shift 2
            ;;
        --) # end argument parsing
            shift
            break
            ;;
        -*|--*=) # unsupported flags
            echo "Error: Unsupported flag $1" >&2
            exit 1
        ;;
        *) # preserve positional arguments
            PARAMS="$PARAMS $1"
            shift
            ;;
  esac
done
# set positional arguments in their proper place
eval set -- "$PARAMS"

{
    # pull required images
    docker pull $IMAGE
    docker pull postgres:9.6

    # start a postgres db
    pg=$(docker run -it --rm -d \
                -e POSTGRES_PASSWORD=admin \
                postgres:9.6)

    # generate the schema by invoking the matching builder
    migrate=$(docker run --link $pg:pg --rm \
                     -d \
                     -e IMAGE=$IMAGE \
                     -v $SCHEMA_BUILDERS:/tmp/schema-builders \
                     --entrypoint /bin/bash \
                     $IMAGE -c "bash /tmp/schema-builders/$IMAGE")
} &> /dev/null

docker wait $migrate >/dev/null

# dump the schema
docker run \
       --link $pg:pg \
       -e PGPASSWORD=admin \
       --rm \
       postgres:9.6 \
       pg_dump -h pg -U postgres $PGDATABASE