langflow/docker_example

Running LangFlow with Docker

This guide will help you get LangFlow up and running using Docker and Docker Compose.

Prerequisites

• Docker
• Docker Compose

Steps

1. Clone the LangFlow repository:

   git clone https://github.com/langflow-ai/langflow.git
   

2. Navigate to the docker_example directory:

   cd langflow/docker_example
   

3. Create a .env file with the LangFlow admin password:

   LANGFLOW_SUPERUSER_PASSWORD=replace-with-a-strong-password
   

   The default admin username is langflow.

4. Run the Docker Compose file:

   docker compose up
   

LangFlow will now be accessible at http://localhost:7860/.

Docker Compose Configuration

The Docker Compose configuration spins up two services: langflow and postgres.

LangFlow Service

The langflow service uses the langflowai/langflow:latest Docker image and exposes port 7860. It depends on the postgres service.

Environment variables:

• LANGFLOW_DATABASE_URL: The connection string for the PostgreSQL database.
• LANGFLOW_SUPERUSER_PASSWORD: The initial admin password. This value is required in .env.
• LANGFLOW_CONFIG_DIR: The directory where LangFlow stores logs, file storage, monitor data, and secret keys.

Volumes:

• langflow-data: This volume is mapped to /app/langflow in the container.

PostgreSQL Service

The postgres service uses the postgres:16-trixie Docker image and exposes port 5432. The image is pinned to a specific Debian base (trixie, Debian 13) so the postgres:16 tag cannot silently roll its underlying OS, which would otherwise produce a glibc collation version mismatch warning on existing data volumes.

Environment variables:

• POSTGRES_USER: The username for the PostgreSQL database.
• POSTGRES_PASSWORD: The password for the PostgreSQL database.
• POSTGRES_DB: The name of the PostgreSQL database.

Volumes:

• langflow-postgres: This volume is mapped to /var/lib/postgresql/data in the container.

Upgrading from a bookworm-initialized volume

Earlier versions of this example used postgres:16, which initially shipped on Debian Bookworm (glibc 2.36). The pinned image now uses Trixie (glibc 2.41). On the first start against a volume that was initialized under Bookworm, PostgreSQL logs a one-time warning:

WARNING: database "langflow" has a collation version mismatch
DETAIL: The database was created using collation version 2.36, but the operating system provides version 2.41.

To clear it, refresh the collation version against the running database (one-off, takes seconds on a typical Langflow database):

docker compose exec postgres \
  psql -U langflow -d langflow \
  -c "REINDEX DATABASE langflow;" \
  -c "ALTER DATABASE langflow REFRESH COLLATION VERSION;"

Fresh installs are unaffected.

Switching to a Specific LangFlow Version

If you want to use a specific version of LangFlow, you can modify the image field under the langflow service in the Docker Compose file. For example, to use version 1.0-alpha, change langflowai/langflow:latest to langflowai/langflow:1.0-alpha.