docker compose copying files example

build.context = folder in which dockerfile is
build.dockerfile = name of dockerfile

When doing COPY command in the Dockerfile then only the files specified by the build.context is available

For example:

You have folder `postgresql` with dockerfile and scripts in.
Then if you have a COPY command in the dockerfile and you want to copy a script such as `initdb.sql`
Like:
COPY initdb.sql /var/lib/postgresql/data
Then your docker-compose.yml need the following config

version: '3'
services:
  database:
    build:
      context: ./postgresql
      dockerfile: postgresql.Dockerfile