IPC Project

This project demonstrates inter-process communication (IPC) in C++ using POSIX message queues. The setup includes a Dockerized Ubuntu 22.04 environment as requested. The development environment goes hand-in-hand with the container, allowing direct development within Ubuntu from any external HOST platform.

Getting Started

Why Docker Compose?

Although this project only uses a single container, Docker Compose simplifies the workflow by:

• Automating container creation and configuration.
• Mapping the project directory into the container for seamless code editing.
• Providing a single command to build and run the environment.

Setup Instructions

1. Build and Start the Docker Container: Stay attached:

   docker-compose up --build

   OR do NOT stay attached:

   docker-compose up -d --build

   This will:

   • Build an Ubuntu 22.04-based development container.
   • Map the project directory into the container under /app.

2. Access the Running Container:

   docker exec -it ipc_dev bash

3. Stop the Container:

   docker-compose down

Running Applications

Running the Transmitter (main_tx)

1. Access the Running Container:

   docker exec -it ipc_dev bash

2. Build the Application:

   cmake -B build -S .
   cmake --build build

3. Run the Transmitter: Inside the container:

   ./build/apps/main_tx

   This will send data to the receiver using IPC.

Running the Receiver (main_rx)

1. Access the Running Container:

   docker exec -it ipc_dev bash

2. Build the Application: (If not already built during the transmitter steps)

   cmake -B build -S .
   cmake --build build

3. Run the Receiver: Inside the container:

   ./build/apps/main_rx

   The receiver will listen for messages and process them as they arrive.

Running Tests

This project uses GoogleTest for unit testing.

Preferred Method: Using GitHub Actions and act

1. GitHub Actions:

   • Tests are automatically run via GitHub Actions whenever changes are pushed to the repository or a pull request is created.
   • The CI workflow builds the Docker image, compiles the project, and runs the tests inside a containerized environment.

2. Run Tests Locally Using act:

   • Install act (GitHub repository) to simulate GitHub Actions workflows locally.
   • Run the workflow:

     act -j test

   • Ensure Docker is running and act is configured correctly (e.g., specifying the container architecture if using an Apple M-series chip).

Alternative: Manual Steps

1. Access the Running Container:

   docker exec -it ipc_dev bash

2. Build the Test Executable: Navigate to the project directory (/app) and run:

   cmake -B build -S .
   cmake --build build

3. Run the Tests: After building, execute the test binary:

   ./build/test_t_ipc_data

   You should see output confirming that the tests pass successfully.

Queue Constants

The constants that define the queue properties, such as name and size, are located in /shared/constants.h. This file ensures both the transmitter (main_tx) and receiver (main_rx) share the same queue definition. Modify this file if you need to adjust the queue properties.

Data Structure Contract

The sender (Tx) and receiver (Rx) communicate using a shared IPCData structure defined in /shared/proto/ipc_data.proto. This structure ensures that both sides use the same definition for the data being transmitted.

Protobuf Integration

The Protobuf compiler (protoc) is explicitly invoked during the build process using a custom CMake command. The project defines the .proto schema in /shared/proto/ipc_data.proto, and the following steps occur automatically:

1. The Protobuf files are compiled with protoc into .pb.h and .pb.cc files.
2. These files are placed in the build directory.
3. A library (proto_generated_lib) is created from the compiled Protobuf files and linked to the project.

If you modify the .proto file, these changes will be incorporated during the next build. You do not need to manually invoke the Protobuf compiler, as the CMake configuration handles everything automatically.

For reference, see the Protobuf-related configuration in CMakeLists.txt.