Device Availability Monitoring Application

Feature List

1. Retrieves a list of device addresses from the devices_list.json file.
2. Watches for changes in the devices_list.json file in real-time.
3. Allows managing the device list through the REST API.
4. Periodically pings devices via REST and gRPC APIs to update their statuses:
   1. Marks a device as StatusUnavailable after one minute of inactivity.
   2. Marks a device as StatusUnknown if no data has ever been received from it.
5. Saves monitoring state to a file. Not a database, ensuring lightweight deployment without external dependencies.
6. Can emulate and act as a monitored device itself.
7. Allows enabling monitoring, REST API, and gRPC API, as well as configuring their ports via config.json.
8. Supports enabling debug mode through config.json for troubleshooting.
9. Allows specifying a path to a checksum application via config.json and can emulate checksum behavior if the application is unavailable.
10. Includes a Swagger specification for the REST API (device info and monitoring methods).
11. All resources (including Swagger files) are embedded into the compiled binary.
12. A Makefile is provided for building the application on popular systems (make build-all) and for running it via Docker (make docker).
13. Generated protobuf files and the vendor directory are committed to the repository for easier setup and reduced external dependencies.
14. Example unit tests available at internal/monitor/monitor_test.go.
15. Example integration tests available at scenarios/start_scenarios.sh:
    Starts monitoring along with 5 simulated devices in different states.
    Some devices are unreachable, one device appears and disappears from the device list, and one device stops responding after 30 seconds.

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Deployment Options

1. go run cmd/main.go and use http://localhost:8080/swagger
2. Download a ready-to-use binary for your platform - https://github.com/chlp/ui/releases/tag/v0.0.1.
3. Build the application manually: see the Makefile or run make build-all.
4. Run via Docker: execute make docker.

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Device List

Edit the devices_list.json file.
The list is updated automatically without restarting the application.

Example:

[
  "127.0.0.1:50052",
  "127.0.0.1:8083",
  "127.0.0.1:8084",
  "127.0.0.1:8085",
  "127.0.0.1:8089"
]

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Application Configuration

Edit the config.json file.
Changes are applied after restarting the application.

Example:

{
  "log_file": "app.log",
  "debug": false,
  "devices_list_file": "devices_list.json",
  "monitor_file": "monitor.json",
  "grpc_port": ":50051",
  "rest_port": ":8080",
  "device": {
    "id": "dev-1743983582705188000",
    "hardware_version": "0.0.1",
    "software_version": "1.0.0",
    "firmware_version": "0.0.5",
    "status": "ok",
    "checksum": ""
  },
  "checksum_cmd": "",
  "checksum_emulate": true
}

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REST API and Swagger Documentation

Swagger specification file:
internal/api/rest/swagger/swagger.yaml

After starting the application (with rest_port=":8080"), Swagger UI is available at:
http://localhost:8080/swagger