Run Postgres in Docker

This guide will use docker-compose which allows us store the docker commands in a serialized and more easily editable format and give us a few bonus super powers such as dependency/load order.

We’ll be using awpl-api’s db as an example here.

Step 1 - Creating the docker-compose.yml §

For this container we’ll use the official pg image which supplies us with a good template to use with compose as a base.

version: '3.3'
services:
  db:
    image: postgres                       # Official pg image
    environment:
      POSTGRES_USER: postgres             # same user account
#     POSTGRES_PASSWORD:                  # password 
      POSTGRES_HOST_AUTH_METHOD: trust    # enable passwordless
      POSTGRES_DB: dev                    # database name
    ports: 
      - 5432:5432                         # Expose default port

Step 2 - Server side env vars §

In awpl-api we have a few env vars that we need to expose

export CUSTOMCONNSTR_SQL_URL="postgres://admin:passwordhere@localhost:5432/dev"
export SQL_SSL="false"
export FB_APP_ACCESS_TOKEN='...'

SQL_SSL is set to true by default (for optimal security) but in local we won’t be signing certs.

CUSTOMCONNSTR_SQL_URL here we pass our custom conn string

(FB_APP_ACCESS_TOKEN is specific to awpl-api)

Step 3 - Run the container §

With docker compose we’ve got a few options.

docker-compose up: creates and starts the containers

docker-compose down: stops the containers and deletes them

docker-compose stop: stops the containers but doesn’t delete them

docker-compose start: starts containers

If you want to maintain data, I’d recommend using start and stop (after a first up). Using down, destroys the container and thus deleting all the data. (Unless a docker volume is used)

For testing/dev work I think this is ideal, up, stop...start and using down only as a means to clear the data without having to worry about complicated pg commands.

Step 4 - Run the API §

Here you can migrate and run your api and it should use the dockerized pg database.

In awpl-api we just need to run npm run migrate:latest && npm run dev

Step 5 - Aliases (optional) §

To use docker-compose, you need to be cd’d into the folder that keeps the docker compose file. Unless of couse you use the -f flag which is for specifing a custom compose filename & path.

Personally, since I use a lot of containers. I have the following structure.

(made into a script if you want to use it too)

mkdir ~/containers/projectName -p;
touch ~/containers/projectName/docker-compose.yml
 
alias projectName="docker-compose -f ~/containers/projectName/docker-compose.yml"

This way from the terminal I can just run projectName start

Step 6 - Profit §

Profit.