How to Connect a Dockerized Python App to Ollama Running on Host (localhost:11434) – Connection Error

I'm running Ollama locally on my machine with the llama3.2:latest model. I can confirm the model is up and running:

ollama ps

Ollama is accessible at http://localhost:11434/.

I have a Python script that uses the pydantic_ai and OpenAIProvider to connect to Ollama via its OpenAI-compatible API. When I run this script directly on my development machine, it works as expected:

from pydantic import BaseModel
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIModel
from pydantic_ai.providers.openai import OpenAIProvider

class CityLocation(BaseModel):
    city: str
    country: str

ollama_model = OpenAIModel(
    model_name='llama3.2', provider=OpenAIProvider(base_url='http://localhost:11434/v1')
)
agent = Agent(ollama_model, output_type=CityLocation)

result = agent.run_sync('Where were the olympics held in 2012?')
print(result.output)
print(result.usage())

Now, I want to run this code inside a Docker container. I built the image using Nixpacks:

sudo nixpacks build . -t image1

It works and tell me to run :

  docker run -it b0300949-bf2f-404e-9ea1-ebaa34423b50

I then run the image with the same command:

But it fails. I have a very long error message ending like that:

openai.APIConnectionError: Connection error

I also tried running the same command with --network="host":

But I still get the same connection error.

Questions:

How can I get my Docker container to successfully connect to Ollama running on my host at http://localhost:11434/v1?

1)first step is probably not necessary for you. But for me Ollama run on windows und the container on WSL..
In %UserProfile% I have written that:

[wsl2]

networkingMode=mirrored

Is I don^t do that WSL and windows have a different localhost

2)

my code :

from pydantic import BaseModel

from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIModel
from pydantic_ai.providers.openai import OpenAIProvider

import requests
try:

    response = requests.get("http://127.0.0.1:11434")
    #response = requests.get("http://localhost:11434") #equivalent
    print("Status code:", response.status_code)
    print("Response body:", response.text)
except requests.exceptions.RequestException as e:
    print("Connection failed:", e)

# exit()

class CityLocation(BaseModel):
    city: str
    country: str

ollama_model = OpenAIModel(
    model_name='llama3.2', 
    provider=OpenAIProvider(base_url="http://127.0.0.1:11434/v1")
    #provider=OpenAIProvider(base_url='http://localhost:11434/v1') #equivalent
)
agent = Agent(ollama_model, output_type=CityLocation)

result = agent.run_sync('Where were the olympics held in 2012?')
print(result.output)
#> city='London' country='United Kingdom'
print(result.usage())
"""
Usage(requests=1, request_tokens=57, response_tokens=8, total_tokens=65, details=None)
"""

3. How the image is created:

sudo nixpacks build . -t image1

4. how the image is launch:

 sudo docker run -it --network host image1

5. the result (it works)

Status code: 200

Response body: Ollama is running

city='London' country='United Kingdom'

Usage(requests=1, request_tokens=176, response_tokens=18, total_tokens=194, details=None)