Learning how to add a PostgreSQL database in a Docker container to a Ruby program by rewiring the Expenses app.

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Setup

• have docker installed
• build your containter: $ docker run --name ruby-postgres -e POSTGRES_PASSWORD=mysecret -d -p 5432:5432 postgres
• Go inside your container and create a database expenses:

$ docker exec -it ruby-postgres bash
root@05b3a3471f6f:/# psql -U postgres
postgres-# CREATE DATABASE expenses;
postgres-# \q
exit

• ready to go: start the app

• Cleaning up when done: Don't forget to clean up the container (and maybe the image too) before you go:

remove the container:

$ docker stop ruby-postgres
$ docker rm ruby-postgres

remove the postgres image:

$ docker rmi postgres

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Expenses app

Small command line application to track expenses

An expense recording system

Commands:

add AMOUNT MEMO [DATE] - record a new expense
clear - delete all expenses
list - list all expenses
delete NUMBER - remove expense with id NUMBER
search QUERY - list expenses with a matching memo field

run: $ ./expense

run a command: $ ./expense add 4.50 coffee