Hosting Langfuse on Amazon ECS with Fargate using CDK Python

This repository contains the AWS CDK Python code for deploying the Langfuse application using Amazon Elastic Container Registry (ECR) and Amazon Elastic Container Service (ECS).

Langfuse is an open-source LLM engineering platform that helps teams collaboratively debug, analyze, and iterate on their LLM applications.

The cdk.json file tells the CDK Toolkit how to execute your app.

This project is set up like a standard Python project. The initialization process also creates a virtualenv within this project, stored under the .venv directory. To create the virtualenv it assumes that there is a python3 (or python for Windows) executable in your path with access to the venv package. If for any reason the automatic creation of the virtualenv fails, you can create the virtualenv manually.

To manually create a virtualenv on MacOS and Linux:

$ python3 -m venv .venv

After the init process completes and the virtualenv is created, you can use the following step to activate your virtualenv.

$ source .venv/bin/activate

If you are a Windows platform, you would activate the virtualenv like this:

% .venv\Scripts\activate.bat

Once the virtualenv is activated, you can install the required dependencies.

(.venv) $ pip install -r requirements.txt

To add additional dependencies, for example other CDK libraries, just add them to your setup.py file and rerun the pip install -r requirements.txt command.

Set up cdk.context.json

Then, we need to set approperly the cdk context configuration file, cdk.context.json.

For example,

{
  "db_cluster_name": "langfuse-db",
  "ecs_cluster_name": "langfuse-cluster",
  "ecs_service_name": "langfuse-alb-service",
  "image_version": "latest",
  "langfuse_env": {
    "NODE_ENV": "production",
    "NEXTAUTH_SECRET": "mysecret",
    "SALT": "mysalt",
    "TELEMETRY_ENABLED": "true",
    "NEXT_PUBLIC_SIGN_UP_DISABLED": "false",
    "LANGFUSE_ENABLE_EXPERIMENTAL_FEATURES": "true"
  }
}

:information_source: NEXTAUTH_SECRET and SALT can be created using openssl rand -base64 32 on MacOS or Ubuntu. (For more information, see Langfuse Configuring Environment Variables)

Deploy

At this point you can now synthesize the CloudFormation template for this code.

(.venv) $ export CDK_DEFAULT_ACCOUNT=$(aws sts get-caller-identity --query Account --output text)
(.venv) $ export CDK_DEFAULT_REGION=$(aws configure get region)
(.venv) $ cdk synth --all

Use cdk deploy command to create the stack shown above.

(.venv) $ cdk deploy --require-approval never --all

We can list all the CDK stacks by using the cdk list command prior to deployment.

(.venv) $ cdk list
LangFuseECRStack
LangFuseVpcStack
LangFuseALBStack
LangFuseAuroraPostgreSQLStack
LangFuseECSClusterStack
LangFuseECSTaskStack
LangFuseECSAlbFargateServiceStack

Clean Up

Delete the CloudFormation stack by running the below command.

(.venv) $ cdk destroy --force --all

Useful commands

• cdk ls list all stacks in the app
• cdk synth emits the synthesized CloudFormation template
• cdk deploy deploy this stack to your default AWS account/region
• cdk diff compare deployed stack with current state
• cdk docs open CDK documentation

Enjoy!

Tracing for your LLM Application with Langfuse

After deploying all CDK stacks, you can find the Langfuse URL using the following command:

aws cloudformation describe-stacks --stack-name LangFuseECSAlbFargateServiceStack | \
  jq -r '.Stacks[0].Outputs | map(select(.OutputKey == "LoadBalancerDNS")) | .[0].OutputValue'

Next, open the Langfuse URL in your browser to create a new project for tracking your LLM application with Langfuse.

Create a New Project in Langfuse

1. Create a Langfuse Account

   

   

2. Create a New Project

3. Create New API Credentials in the Project Settings

Log Your First LLM Call to Langfuse

Open the tracing_for_langchain_bedrock notebook in the examples folder and run it. (See here for more information)

You will the see the list of traces as follows:

You will also see the details of the selected trace as follows:

References

• (AWS Korea Tech Blog) Hosting Langfuse on Amazon ECS with Fargate using AWS CDK Python (2024-08-09)
• Langfuse Official Documents - Langfuse is an open-source LLM engineering platform that helps teams collaboratively debug, analyze, and iterate on their LLM applications.
  • Langfuse Self-Hosting Guide (Docker)
  • Langfuse Configuring Environment Variables
  • Tracing for Langchain (Python & JS/TS)
  • Langfuse Python SDK (Low-level)
• Langfuse Cookbook
• (GitHub) Langfuse - 🪢 Open source LLM engineering platform: Observability, metrics, evals, prompt management, playground, datasets. Integrates with LlamaIndex, Langchain, OpenAI SDK, LiteLLM, and more.
• Langfuse ECR/ECS Deployment CDK TypeScript - Deploy Langfuse to ECR and ECS with Fargate and AWS CDK TypeScript.
• cdk-ecr-deployment - A CDK construct to deploy docker image to Amazon ECR.

Security

See CONTRIBUTING for more information.

License

This library is licensed under the MIT-0 License. See the LICENSE file.