题意：在Docker容器之间连接Weaviate与Langflow

问题背景：

I am trying to build a local RAG application using Langflow. For my vectore store, I want to use a local Weaviate instance, hosted in a separate docker container on the same network. Building the Weaviate component in Langflow fails, and throws an error:

Error Building Component

    Error building Component Weaviate: HTTPConnectionPool(host='localhost', port=8080): Max retries exceeded with url: /v1/.well-known/openid-configuration (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7fb2a2db9fa0>: Failed to establish a new connection: [Errno 111] Connection refused'))

My setup: Docker for Desktop v4.31.1 on Windows Compose file:

version: "3.9"
name: proto_rag

services:
  langflow:
    image: langflowai/langflow:1.0-alpha
    ports:
      - "7860:7860"
    depends_on:
      - postgres
    environment:
      - LANGFLOW_DATABASE_URL=postgresql://langflow:langflow@postgres:5432/langflow
      # This variable defines where the logs, file storage, monitor data and secret keys are stored.
      - LANGFLOW_CONFIG_DIR=app/langflow
    volumes:
      - langflow-data:/app/langflow

  postgres:
    image: postgres:16
    environment:
      POSTGRES_USER: langflow
      POSTGRES_PASSWORD: langflow
      POSTGRES_DB: langflow
    ports:
      - "5432:5432"
    volumes:
      - langflow-postgres:/var/lib/postgresql/data

  weaviate:
    command:
    - --host
    - 0.0.0.0
    - --port
    - '8080'
    - --scheme
    - http
    image: cr.weaviate.io/semitechnologies/weaviate:1.25.4
    ports:
    - 8080:8080
    - 50051:50051
    volumes:
    - weaviate_data:/var/lib/weaviate
    restart: on-failure:0
    environment:    
      AUTHENTICATION_ANONYMOUS_ACCESS_ENABLED: 'true'
      DISABLE_TELEMETRY: 'true'
      PERSISTENCE_DATA_PATH: '/var/lib/weaviate'
      DEFAULT_VECTORIZER_MODULE: 'text2vec-ollama'
      ENABLE_MODULES: 'text2vec-ollama'
      CLUSTER_HOSTNAME: 'node1'  

  ollama:
    volumes:
     - ollama:/root/.ollama
    ports:
     - 11434:11434
    container_name: ollama
    image: ollama/ollama

volumes:
  langflow-postgres:
  langflow-data:
  ollama:
  weaviate_data:

My weaviate component in Langflow calls http://localhost:8080 and has the variable "index name" set to "vector_store".

Connecting to ollama on localhost works, so it doesn't seem to be a network problem. However since AUTHENTICATION_ANONYMOUS_ACCESS_ENABLED is set true I can't see a reason why weaviate would refuse the connection.

I tried setting up users and API keys in the compose file and using the key in the langflow component, this had no effect.

[...]
      AUTHENTICATION_APIKEY_ENABLED: 'true'
      AUTHENTICATION_APIKEY_ALLOWED_KEYS: 'key206339812'
      AUTHENTICATION_APIKEY_USERS: 'user206339812'
[...]

I also tried raising the Query limit, which also had no effect.

      QUERY_DEFAULTS_LIMIT: 1000

This thread suggests to use the service/container name for reference instead of localhost, this failed aswell.

问题解决：

Indeed, your error message is consistent with that thread's one. Looks like your Langflow is trying to connect to weaviate at http://localhost:8080.

Considering you are using docker, this is not the place where Langflow will find Weaviate, but http://weaviate:8080

I have used your docker-compose, and was able to ingest data using this simple flow in Langflow:

Let me know if this helps.