Enable the integration tests for Ollama

[rdimitrov]

The following PR enables the integration tests for Ollama.

Details:

• Starts the CodeGate container in the host network (so everything can talk to each other without the need to specify explict ports), we don't have port conflicts anyway
• Starts the Ollama container and tests if it runs
• Downloads and runs the qwen2.5-coder:0.5b model
• Updates the tests to use qwen2.5-coder:0.5b
• Updates the chat test to expect a simpler welcome message
• Adds a missing header in the tests

Fixes: #815

[jhrozek]

I think this is a bug in the text that uncovers a bug in codegate:

decoded_line = ' {"error": "[Errno -2] Name or service not known", "type": "error",      │ │
│ │                    "choices": ['+2                                                           │ │
│ │                e = IndexError('list index out of range')                                     │ │
│ │        json_line = {                                                                         │ │
│ │                    │   'error': '[Errno -2] Name or service not known',                      │ │
│ │                    │   'type': 'error',                                                      │ │
│ │                    │   'choices': []                                                         │ │
│ │                    }                                                                         │ │
│ │             line = b'data: {"error": "[Errno -2] Name or service not known", "type":         │ │
│ │                    "error", "choice'+7                                                       │ │

So what happens here is that we get a line and expect it to cointain choices but it only contains an error. We should handle the error, perhaps by raising an HTTP exception. But the root cause is that we cannot reach a service (or ollama can't?)

[rdimitrov]

I think this is a bug in the text that uncovers a bug in codegate:

decoded_line = ' {"error": "[Errno -2] Name or service not known", "type": "error",      │ │
│ │                    "choices": ['+2                                                           │ │
│ │                e = IndexError('list index out of range')                                     │ │
│ │        json_line = {                                                                         │ │
│ │                    │   'error': '[Errno -2] Name or service not known',                      │ │
│ │                    │   'type': 'error',                                                      │ │
│ │                    │   'choices': []                                                         │ │
│ │                    }                                                                         │ │
│ │             line = b'data: {"error": "[Errno -2] Name or service not known", "type":         │ │
│ │                    "error", "choice'+7                                                       │ │

So what happens here is that we get a line and expect it to cointain choices but it only contains an error. We should handle the error, perhaps by raising an HTTP exception. But the root cause is that we cannot reach a service (or ollama can't?)

Thanks! I'll file a separate issue for this and fix it there.

[jhrozek]

yay!