This image extends the official Postgres image to support:

• Dynamic creation of multiple databases and users at initialization
• Automatic enabling of the pgvector extension for databases prefixed with VECTOR_
• Admin and user role setup via environment variables
• Use of gettext/envsubst for dynamic templating

• Features
• Project Structure
• Requirements
• Build and Run with Docker
• Prebuilt Docker Image
• Example Usage
• Environment Variables
• Sidecar Database Logic
• How It Works
• Overriding Defaults
• Notes
• Contributing
• License
• References

• Multi-database initialization: Create any number of databases and users at container startup.
• pgvector support: If a database name starts with VECTOR_, the pgvector extension is enabled in that database.
• Admin user: Optionally create a superuser admin role.
• Sidecar users: Each sidecar database gets a user with the pattern <db>_user (all lowercase) and a default password.

postgres-pgvector-multidatabase/ ├── Dockerfile # Docker build instructions for the custom Postgres image ├── init-multidb.sh # Initialization script for dynamic multi-database and user setup ├── init.sql.template # SQL template used for database/user creation and extension enabling ├── LICENSE.md # Project license (MIT) ├── README.md # Project documentation and usage instructions 

• Docker
• Docker Compose (optional, for multi-container setups)

docker build -t custom-postgres-multidb-pgvector .

docker run -d \ --name my-postgres \ -e POSTGRES_USER=pguser \ -e POSTGRES_PASSWORD=pguserstrongpassword \ -e POSTGRES_DB=postgres \ -e POSTGRES_DB_SIDECARS=db1,db2,VECTOR_db3 \ -p 5432:5432 \ custom-postgres-multidb-pgvector

You can adjust the environment variables as needed.

A prebuilt image is available on Docker Hub:

luismachadoreis/postgres-multidb-pgvector:pg17

• Use the pg17 tag for AMD64 (x86_64) systems:

  docker pull luismachadoreis/postgres-multidb-pgvector:pg17

• Use the pg17-arm64 tag for ARM64 (Apple Silicon, Raspberry Pi, etc):

  docker pull luismachadoreis/postgres-multidb-pgvector:pg17-arm64

You can use the appropriate image in your docker run or docker-compose.yml as the base image for your platform.

version: '3.8' services: postgres: build: . environment: POSTGRES_USER: pguser POSTGRES_PASSWORD: pguserstrongpassword POSTGRES_DB: postgres POSTGRES_DB_SIDECARS: db1,db2,VECTOR_db3 ports: - "5432:5432" volumes: - pgdata:/var/lib/postgresql/data volumes: pgdata:

• For each database in POSTGRES_DB_SIDECARS:
  • A database is created (if it doesn't exist)
  • A user is created: <db>_user (all lowercase), password: mydefaultpassword
  • The user is granted all privileges on their database
  • If the database name starts with VECTOR_, the pgvector extension is enabled in that database

• On first container startup, the script init-multidb.sh runs.
• It reads the environment variables and creates the specified databases and users.
• For any database with a name starting with VECTOR_, it enables the pgvector extension.
• All sidecar users get the password mydefaultpassword (change in script if needed).

You can override any environment variable at build or runtime. For example, to add more vector-enabled databases:

 POSTGRES_DB_SIDECARS: db1,VECTOR_embeddings,VECTOR_analytics

• The default user and database logic is compatible with the official Postgres image.
• The admin user is optional but recommended for superuser access.
• The pgvector extension is built from source at image build time.

git clone git@github.com:luismr/postgres-17-multidb-pgvector.git cd postgres-17-multidb-pgvector

1. Fork this repository on GitHub.
2. Create a new branch for your feature or fix:

   git checkout -b my-feature-branch

3. Make your changes and commit them with clear messages.
4. Push your branch to your fork:

   git push origin my-feature-branch

5. Open a Pull Request on GitHub from your branch to the main branch of this repository.
6. Provide a clear description of your changes in the PR.

MIT License

• Docker Documentation
• Docker Compose Documentation
• PostgreSQL 17 Documentation
• pgvector Extension