Vnc Recorder Daemon

A golang based gRPC service API that connects to a VNC host and records the frames using ffmpeg library and vnc2video.

Features

• Concurrent VNC recordings
• Custom recording file name
• Unique VNC host per request
• VNC encoding format per request
• Custom quality and frame rate
• Dockerized setup

Usage

gRPC code generation

• Copy to the api/vnc.proto protobuf file in your project of the language of your choice, and adjust the options for the target directory for code generation.

• Follow the instructions from https://grpc.io/docs/ to generate the gRPC client side code from the protobuf file.

Service APIs

The api/vnc.proto exposes the VncRecorder service with three APIs

• Start - Starts recording from VNC server
• Stop - Stops the recording and saves it in the target file.
• Remove - Stops the recording and removes the recording file.

Each of the service APIs accept VncRequest as a parameter and returns a VncResponse result.

The VncRequest message type has four fields - one is required and three are optional:

• host - The hostname/IP address where the VNC server for the target recording is running.
• port - (Optional) The port on which VNC server is listening. Default value is 5900 or the one set for VNC_PORT.
• fileName - (Optional) The name of file in which the vnc recording should be saved. If a path is provided, the absolute path would be relative to either /recordings or the value of VNC_RECORDINGS_DIR if set. If file name is not provided, the recording will be saved in vnc file.
• mediaType - (Optional) The target format of the recording. Defaults to mp4.

The VncResponse message type has two fields:

• status - Returns the status of the VNC recording request. If no errors happen, then a status of STARTED for Start service request, and DONE for Stop and Remove service request types. On any errors, the status code will be FAILURE.
• message - Returns a failure message. If no errors happened, then message is empty.

Running

Bare metal

• Build the go project by executing go build
• Export the environment variables for any customization see Configuration Options below.
• Run the binary executable

Docker compose setup

• Check out the sample docker-compose.yaml file at the root of this project
• Adjust the environment variables in the .env file
• Execute docker-compose up -d && docker-compose logs -f vncrecorder

Configuration Options

The VNC recorder service allows you to customize the below parameters:

• VNC_PASSWORD - The password used to authenticate with the VNC server. Default value is secret.
• VNC_PORT - The port on which the VNC server is listening. Default value is 5900.
• GRPC_PORT - The port on which the VNC recording gRPC service is available. Default value is 3000. This parameter is useful when running in bare metal scenario when you have other services running on port 3000. When running as a docker service, only the exposed port mapping needs to be adjusted.
• VNC_RECORDINGS_DIR - The directory where VNC recordings are stored. Default value is /recordings.
• VNC_FRAME_RATE - Number of frames per second the target recording file will contain. Default value is 60.
• VNC_CONSTANT_RATE_FACTOR - Quality of the recording. Default value is 0 - (best). Valid range is 0-51 where 0 is the best and 51 is the worst.