chore(wren-ai-service): separate the api key for each LLM and embedder

[paopa]

This PR introduces a clear separation between API keys used for LLM and Embedder services.

Changes

• Split OPENAI_API_KEY into LLM_OPENAI_API_KEY and EMBEDDER_OPENAI_API_KEY
• Split AZURE_OPENAI_API_KEY into LLM_AZURE_OPENAI_API_KEY and EMBEDDER_AZURE_OPENAI_API_KEY
• Updated all relevant configuration files and deployment templates
• Modified provider initialization to use specific API keys

Implementation Details

Environment Variables

- OPENAI_API_KEY=
- AZURE_OPENAI_API_KEY=
+ LLM_OPENAI_API_KEY=
+ EMBEDDER_OPENAI_API_KEY=
+ LLM_AZURE_OPENAI_API_KEY=
+ EMBEDDER_AZURE_OPENAI_API_KEY=

Provider Updates

• Updated OpenAI LLM provider to use LLM_OPENAI_API_KEY
• Updated OpenAI Embedder provider to use EMBEDDER_OPENAI_API_KEY
• Updated Azure OpenAI providers to use their respective keys
• Removed fallback to generic API keys

Deployment Changes

• Updated Kubernetes deployment configurations
• Modified Docker Compose files to use new environment variables
• Updated example configuration files and documentation
• Modified Wren launcher to handle separate API keys

[paopa]

@cyyeh I've tried to leave an empty key when langfuse enabling. langfuse client disables itself when key is none or empty string. thus i think we can keep the setting default as true.

here is the source code of langfuse

        if not self.enabled:
            self.log.warning(
                "Langfuse client is disabled. No observability data will be sent."
            )

        elif not public_key:
            self.enabled = False
            self.log.warning(
                "Langfuse client is disabled since no public_key was provided as a parameter or environment variable 'LANGFUSE_PUBLIC_KEY'. See our docs: https://langfuse.com/docs/sdk/python/low-level-sdk#initialize-client"
            )

        elif not secret_key:
            self.enabled = False
            self.log.warning(
                "Langfuse client is disabled since no secret_key was provided as a parameter or environment variable 'LANGFUSE_SECRET_KEY'. See our docs: https://langfuse.com/docs/sdk/python/low-level-sdk#initialize-client"
            )

[cyyeh]

LGTM, thanks a lot!

[paopa]

Migration Guide for Developers Using Docker Compose

After merging PR #792 and this one, follow these steps to update your configuration:

1. Copy the Configuration Example:

   • Navigate to config.example.yaml and copy the file.

2. Rename the Configuration File:

   • Rename the copied file to config.yaml.

For more detailed information, please refer to the How to Start with OpenAI section in the Docker README.