Docker-Compose and Postgres Extensions

Question

This is my docker-compose file. Is there any easy way to get a postgres extension installed? I'm trying to install pg_trgm.

Edit: I now have two dockerfiles and an install script. It doesn't seem to be working when I run docker-compose up build

Internal server error: pq: operator does not exist: character varying % unknown

services:
  db:
    build:
      context: .
      dockerfile: db/Dockerfile
    image: postgres
    ports:
      - "5432:5432"
    environment:
      - POSTGRES_USER=x
      - POSTGRES_PASSWORD=x
      - POSTGRES_DB=x

  api:
    build:
      context: .
      args:
        app_env: ${APP_ENV}
    volumes:
      - .:/go/src/x/y/z
    ports:
      - "8080:8080"

db/Dockerfile:

FROM postgres
COPY db/install-extensions.sql /docker-entrypoint-initdb.d

db/install-extensions.sql

CREATE EXTENSION IF NOT EXISTS pg_trgm;

Answer 1

Try this

FROM postgres
COPY ./install-extensions.sql /docker-entrypoint-initdb.d

and remove db from your file.

OR you can write

version: "3.1"

services:
  db:
    image: postgres:9.6
    restart: always
    environment:
      POSTGRES_PASSWORD: unit
      POSTGRES_USER: unit
      POSTGRES_DB: unit
    ports:
      - 5432:5432
    volumes:
      - ./scripts:/docker-entrypoint-initdb.d

then

1. create directory scripts
2. put your .sql or .sh file
3. remove created containers docker-compose rm -v
4. start docker docker-compose up --build
5. in logs you must see something like this:

created_extension