Custom PostgreSQL Docker Image

This repository contains the Dockerfile and associated scripts for building a custom PostgreSQL Docker image. The unique feature of this image is a modification to the PostgreSQL source code to support longer identifier lengths. This is achieved by increasing NAMEDATALEN from the default of 64 to 151.

The Dockerfile includes procedures for fetching the PostgreSQL source, patching the pg_config_manual.h file, compiling the server with the new identifier length, and setting up the container environment.

Prerequisites

Before building and running this custom PostgreSQL Docker image, make sure you have the following prerequisites installed:

• Docker Engine

Building the Image

To build the Docker image from this repository, run the following command in the root directory where the Dockerfile is located:

docker build -t your-username/postgres_custum:latest .

Replace your-username with your Docker Hub username or any other username you prefer for naming your Docker images.

Running the Container

To run a container based on the built image, execute the following command:

docker run -d \
  -e POSTGRES_PASSWORD=mysecretpassword \
  -v custom_pgdata:/var/lib/postgresql/data \
  -p 5432:5432 \
  your-username/postgres_custum:latest

Replace mysecretpassword with a secure password of your choice. The -v option mounts a volume for PostgreSQL data persistence, and the -p option maps the default PostgreSQL port from the container to the host.

Custom PostgreSQL Configuration

The key feature of this Docker image is an increased maximum identifier length for database objects, such as table names, column names, and others. Using a sed command during the build process, the NAMEDATALEN parameter in pg_config_manual.h is changed:

RUN sed -i 's/#define NAMEDATALEN 64/#define NAMEDATALEN 151/g' pg_config_manual.h

This customization allows identifiers to be up to 151 characters long rather than the default 64 characters.

Environment Variables

When you start the PostgreSQL container, you can adjust the configuration by passing one or more environment variables to the docker run command.

• POSTGRES_PASSWORD (required): The password for the PostgreSQL superuser.
• POSTGRES_USER: The superuser username (default: postgres).
• POSTGRES_DB: The name of the default database to create (default: value of POSTGRES_USER).
• POSTGRES_HOST_AUTH_METHOD: The authentication method for local connections (default: md5).

Initialization Scripts

If you need to execute additional SQL or shell scripts upon container initialization, place them in the /docker-entrypoint-initdb.d/ directory. This can be achieved by mounting a host directory containing your initialization scripts:

docker run -d \
  -e POSTGRES_PASSWORD=mysecretpassword \
  -v custom_pgdata:/var/lib/postgresql/data \
  -v /path/to/initdb/scripts:/docker-entrypoint-initdb.d \
  -p 5432:5432 \
  your-username/postgres_custum:latest

Scripts in /docker-entrypoint-initdb.d/ will be executed in alphabetical order. SQL files will be imported by default into the database specified by POSTGRES_DB, and shell scripts will be executed as-is.

License

This repository is available under the terms of the MIT License.

Contributing

If you have any improvements or suggestions, please open an issue or pull request on GitHub.

Acknowledgments

This custom PostgreSQL image builds upon the work of the PostgreSQL community and the robustness of the official PostgreSQL Docker image.

This is from docker-library/postgres