How to create custom PostgreSQL Docker images for Fly.io

readme.md

How to create a custom PostgreSQL Docker image for Fly.io

Fly.io has some specific setup for PostgreSQL Docker images, which means that your best bet is to start from their base image and then customize it. Luckily, their base image is based on the official PostgreSQL repo for Ubuntu, so installing additional extensions is very easy.

1. Choose a Dockerfile from below, we've provided two examples, one for pgvector and another for postgis.

   You can also create your own by following the same pattern, by adding the installation steps for the PostgreSQL extension you want to install.

2. Login to Docker Hub:

   docker login

3. Build and push the image to Docker Hub. Replace the variables below with your own values:

   username=your-dockerhub-username   # the user you just logged in to Docker Hub with
   image_name=custom-fly-docker       # or a more descriptive one, e.g. fly-postgis
   dockerfile=path-to-your-dockerfile # e.g. ./pgvector.Dockerfile or ./postgis.Dockerfile
   
   docker build --tag $username/$image_name --push --file $dockerfile .

4. Ready! You can now use your new image when setting up your app with Wasp deploy. Replace the variables below with your own values:

   wasp deploy fly setup --db-image $username/$image_name $app_name $region

pgvector.Dockerfile

# syntax=docker/dockerfile:1
# check=skip=FromPlatformFlagConstDisallowed (Fly.io only has amd64 machines)

FROM --platform=linux/amd64 flyio/postgres-flex:17

RUN <<EOF
  apt-get update -y
  apt-get install -y postgresql-$PG_MAJOR_VERSION-pgvector
  apt-get clean -y
EOF

postgis.Dockerfile

# syntax=docker/dockerfile:1
# check=skip=FromPlatformFlagConstDisallowed (Fly.io only has amd64 machines)

FROM --platform=linux/amd64 flyio/postgres-flex:17

RUN <<EOF
  apt-get update -y
  apt-get install -y postgresql-$PG_MAJOR_VERSION-postgis-3
  apt-get clean -y
EOF