Discourse Docker service fails to start properly

Installation
1

I wanted to try Discourse locally, so I used Docker Compose to set it up:

version: '3.8'

services:
  postgres:
    image: pgvector/pgvector:pg17
    container_name: discourse-postgres
    restart: always
    environment:
      POSTGRES_USER: discourse
      POSTGRES_PASSWORD: discourse
      POSTGRES_DB: discourse
      # Ensure the extension loads correctly
      # POSTGRES_INITDB_ARGS: "--enable-extensions=vector"
    volumes:
      - ./data/postgres:/var/lib/postgresql/data
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U discourse && psql -U discourse -c 'SELECT * FROM pg_extension WHERE extname = ''vector'';'"]
      interval: 10s
      timeout: 5s
      retries: 5

  redis:
    image: redis:7-alpine
    container_name: discourse-redis
    restart: always
    volumes:
      - ./data/redis:/data
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 10s
      timeout: 5s
      retries: 5

  discourse:
    image: discourse/discourse:stable
    container_name: discourse-app
    restart: always
    depends_on:
      postgres:
        condition: service_healthy
      redis:
        condition: service_healthy
    ports:
      - "80:80"
    environment:
      DISCOURSE_DB_HOST: postgres
      DISCOURSE_DB_USER: discourse
      DISCOURSE_DB_PASSWORD: discourse
      DISCOURSE_REDIS_HOST: redis
      DISCOURSE_DEVELOPER_EMAILS: "admin@example.com"
      DISCOURSE_HOSTNAME: "localhost"
      # Temporary SMTP configuration (must be changed to real values after startup)
      DISCOURSE_SMTP_ADDRESS: "smtp.example.com"
      DISCOURSE_SMTP_PORT: 587
      DISCOURSE_SMTP_USER_NAME: "admin@example.com"
      DISCOURSE_SMTP_PASSWORD: "password"
      # Optional: Disable unnecessary AI features to reduce extension dependencies (if needed)
      DISCOURSE_DISABLE_VECTOR_SEARCH: "true"
    volumes:
      - ./data/discourse:/var/www/discourse/shared

However, I encountered an issue preventing me from experiencing the Discourse forum:

discourse-postgres  | 2026-01-20 09:19:47.774 UTC [140] ERROR:  column "vector" does not exist at character 44
discourse-postgres  | 2026-01-20 09:19:47.774 UTC [140] STATEMENT:  SELECT * FROM pg_extension WHERE extname = vector;

I’m not sure what the reason is. Can any experienced user provide guidance?

2

This is not a Bug. This is not the supported local install. See dev-install

2 Likes
3

You need the pgvector extension for postgres. Also, discourse won’t work without https. If you really want a local install, you should use development install.