[Example] ggml: add nnrpc example for RPC usage

[dm4]

• Add the nnrpc example to avoid LoadByNameWithConfig usage before implement it in wasmedge.
• Add the CI test to build the nnrpc example. Since we need to build from the WasmEdge source to obtain the wasi_nn_rpcserver binary, we will not test the RPC server/client in this repository.

[juntao]

Hello, I am a code review bot on flows.network. Here are my reviews of code commits in this PR.

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Potential Issues and Errors:

1. Commit Message and Context: The commit message lacks detailed context about the purpose and benefits of adding the new RPC example.

2. Environment Setup and Dependencies: The patch assumes specific setups and relies on external resources, which may cause failures or instability in different environments.

3. Incomplete Comment and Error Handling: The main.rs Rust code includes incomplete comments and minimal error handling, potentially leading to issues during execution.

4. Command Complexity and Security Risks: Long commands and the use of external resources (like curl) pose maintenance challenges and security risks that need mitigation.

5. Testing Information and Documentation: Lack of clear testing criteria, configuration variable details, and job documentation hinders understandability and maintenance.

Important Findings:

• Added Functionality: The PR introduces an RPC example for RPC usage with wasmedge-ggml, expanding the project's capabilities.
• Enhanced User Interaction: Detailed instructions in the README.md improve user experience in understanding and interacting with the new example.
• Workflow Integration: Testing the RPC example within the llama workflow enhances project testing practices.
• Environment Variables for Customization: The inclusion of environment variables for setting options provides flexibility to users in configuration.

Recommendations:

1. Enhanced Documentation: Provide detailed commit message context, expand README clarity, and improve job comments for better understanding and maintenance.
2. Robustness Improvement: Enhance error handling, input validation, and ensure adherence to project coding standards for code robustness.
3. Dependency Mitigation: Address environmental dependencies and external resource reliance to enhance project stability and control.
4. Simplify Commands: Consider breaking down long commands into manageable steps for improved readability and maintainability.
5. Security Measures: Implement validation checks for downloaded resources to mitigate potential security risks.
6. Testing Clarity: Define expected outcomes and assertions for accurate testing of the new RPC example.

Overall Summary:

The PR introduces valuable RPC functionality and detailed instructions for users, along with enhanced testing within the llama workflow. However, it is crucial to address issues related to commit context, environment setup, dependencies, code robustness, command complexity, security, testing clarity, and documentation to ensure the smooth integration and maintainability of the new RPC example.

Details

Commit ffdfd3fb6a8a5241f740a443436923d32b40d463

Key changes:

1. Added a new example for RPC usage with wasmedge-ggml in the nnrpc directory.
2. Added Cargo.toml, README.md, main.rs, and wasmedge-ggml-nnrpc.wasm files to support the RPC example.
3. Created a Rust program in main.rs that handles input processing, setting options, setting context data, and extracting results from the context. This program interacts with the WASI-NN backend for graph execution.
4. Provided detailed instructions in the README.md file on setting parameters, executing the RPC server and the program, and interactions with the program.
5. Introduced environment variables for setting options like logging, GPU layers, and context size for inference.

Potential problems and recommendations:

1. The commit message and code changes seem fine, but the patch lacks detailed commit message context. It would be helpful to explain why this example was added and how it benefits users.
2. The README file could be expanded to provide more context on the purpose of this new RPC example and include any dependencies or prerequisites for running the example successfully.
3. The Rust code in main.rs has a comment reset_p that seems incomplete, which could lead to issues if not handled properly.
4. The error handling in the Rust program is minimal, and it may need enhancement to provide better user feedback in case of failures.
5. Check the handling of user input and ensure it's robust against unexpected inputs.
6. Ensure that the new code follows the project's coding style and best practices consistently.

Commit ea1ed93f4e70c8b16813971b8c6e866a3c5673f2

Key Changes:

1. Added a new job in the YAML file for testing an RPC example within the llama workflow.
2. The added job downloads a file, builds it using Cargo, and runs it with specific configurations for Wasmedge.
3. The RPC example seems to involve setting up an AI assistant that responds to a given prompt/question in a socially unbiased and positive manner.

Potential Problems:

1. Environment Setup: The script assumes a specific setup (~/.wasmedge/env) which might not exist in all developer environments. This could cause the job to fail if that setup is not present.

2. Dependency on External Resources: The job downloads a file from an external source (https://huggingface.co/...). This introduces a reliance on an external resource that may not be under the direct control of the project. It's important to consider stability and availability issues related to external dependencies.

3. Long Command: The script runs a long command for building and running the example. Such long commands can be difficult to maintain and debug. It may be worth splitting this into separate steps or scripts for better readability and maintainability.

4. Configuration Variables: The job uses a configuration variable ($NGL) without providing information on where this variable is set or its potential values. Clarification on this would be helpful for better understanding the job.

5. Missing Testing Information: While the job tests the RPC example, it doesn't provide information on the expected outcomes or assertions. It's essential to have clear testing criteria to validate the correctness of the RPC example.

6. Potential Security Risks: Running commands like curl without verifying the source or contents of the downloaded file could introduce security risks if the source is compromised.

7. Documentation: The added job lacks detailed comments or documentation explaining its purpose and how it fits into the overall workflow. This could make it harder for other team members to understand the job's role and significance.

Overall Impression:

The PR introduces a new test job for an RPC example in the llama workflow. While the addition of testing for the example is beneficial, there are potential issues related to environment setup, external dependencies, command complexity, security, testing clarity, and documentation that need to be addressed for a smoother integration and better maintainability.