Connect to PostgreSQL database using Heroku addon

2020-04-27

Motivation

This article is a hands-on guide on how to create and operate the Heroku PostgreSQL database.

Goals

1. Setup and config Heroku addon that supports PostgreSQL operation
2. Implement basic user management (CURD) for the bdmhero project.

References

• Heroku Postgres: https://devcenter.heroku.com/articles/heroku-postgresql
• Install PostgreSQL on Mac https://postgresapp.com

Steps

1. Create DB plan for PostgreSQL (DB provision process)
   Command to display all created addons

heroku addons

Add-on                                      Plan       Price  State
──────────────────────────────────────────  ─────────  ─────  ───────
heroku-postgresql (postgresql-rigid-16229)  hobby-dev  free   created
 └─ as DATABASE

The table above shows add-ons and the attachments to the current app (bdmhero) or other apps.

Command to create PostgreSQL if it's not available yet.

heroku addons:create heroku-postgresql:hobby-dev

Creating heroku-postgresql:hobby-dev on ⬢ bdmhero... free
Database has been created and is available
 ! This database is empty. If upgrading, you can transfer
 ! data from another database with pg:copy
Created postgresql-rigid-16229 as DATABASE_URL
Use heroku addons:docs heroku-postgresql to view documentation

Command to check DATABASE_URL, as well as other defined configs

heroku config

=== bdmhero Config Vars
DATABASE_URL:                postgres://hxgombqjtymuoh:bc403c8a4db1581bf339672b93911da6170872c052fb4cde8e94574ef942d7e2@ec2-54-88-130-244.compute-1.amazonaws.com:5432/dkak1glce3uq8
MYSQL_DOCKER_CONTAINER_NAME: bdhero
MYSQL_HOST_ADDR:             192.168.7.169
MYSQL_HOST_DB_NAME:          dkak1glce3uq8
MYSQL_HOST_PORT:             5432
MYSQL_HOST_PSWD:             bc403c8a4db1581bf339672b93911da6170872c052fb4cde8e94574ef942d7e2
MYSQL_HOST_USER:             hxgombqjtymuoh
......

Command to check Postgres DB info

heroku pg:info

=== DATABASE_URL
Plan:                  Hobby-dev
Status:                Available
Connections:           0/20
PG Version:            12.2
Created:               2020-04-27 11:20 UTC
Data Size:             7.9 MB
Tables:                0
Rows:                  0/10000 (In compliance)
Fork/Follow:           Unsupported
Rollback:              Unsupported
Continuous Protection: Off
Add-on:                postgresql-rigid-16229

Running Postgre Locally

1. Install PostgreSQL on Mac
2. Export DATABASE_URL locally

export DATABASE_URL=postgres://$(whoami)

3. Establish a PostgreSQL session with the remote database

heroku pg:psql

➜  cloudme git:(gs-accessing-data-mysql) ✗ heroku pg:psql
--> Connecting to postgresql-rigid-16229
psql (12.1, server 12.2 (Ubuntu 12.2-2.pgdg16.04+1))
SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: off)
Type "help" for help.