yakapi

README

YakAPI Server

The YakAPI Server is meant to run on Rovers to provide an API for it. It is extensible by allowing implementation specific software to participate in a Rover software ecosystem using Redis as middleware.

Usage

yakapi acts as a http server that presents a JSON API

API

The JSON API is versioned, so start with /v1 and you'll receive a nice hello:

$ curl -s http://localhost:8080/v1 | jq .
{
  "name": "YakAPI (development)",
  "uptime": 1,
  "resources": [
    {
      "name": "metrics",
      "ref": "/metrics"
    },
    {
      "name": "ci",
      "ref": "/v1/ci"
    },
    {
      "name": "cam",
      "ref": "/v1/cam/capture"
    },
    {
      "name": "project",
      "ref": "https://github.com/rhettg/batteries/yakapi"
    }
  ]
}

Services

YakAPI requires additional services to provide actual functionality. It communicates with these services via Redis Streams. An example implementation is provided in examples/ci.py.

Development

YakAPI lives by scripts-to-rule-them-all rules.

But dependencies and setup are limited. Really you should be able to go out of the box with:

$ script/server
2022-05-13T03:09:53.020Z        INFO    yakapi/main.go:218      starting        {"version": "1.0.0", "port": "8080"}

Production

Sky is the limit, but for easy integration a Dockerfile is provided that is easily customized by environment variables.

$ docker build -f Dockerfile -t yakapi:latest .
...
$ docker run --rm \
  -p 80:8080 \
  -e YAKAPI_NAME="My Rover" \
  -e YAKAPI_REDIS_URL="127.0.0.1:6379" \
  -e YAKAPI_CAM_CAPTURE_PATH="/var/cam/capture.jpeg" \
  -v /var/cam:/var/cam \
 yakapi:latest 
...

Configuration

Configuration is primarily through environment variables

• YAKAPI_PORT [default 8080] port for api server to listen on
• YAKAPI_NAME [default YakBot] name for rover
• YAKAPI_REDIS_URL [default redis://localhost:6379] URL for redis server
• YAKAPI_PROJECT_URL [default https://github.com/The-Yak-Collective/yakrover] URL for more information
• YAKAPI_CAM_CAPTURE_PATH path to image for camera.

Components

Metrics

Metrics are served in prometheus format:

$ curl -s http://localhost:8080/metrics
# HELP yakapi_processed_ops_total The total number of processed requests
# TYPE yakapi_processed_ops_total counter
yakapi_processed_ops_total 0
...

ci (command injection)

This service translates commands into motor settings. There are two redis streams that a implementation must interact with:

• yakapi:ci stream of accepted commands
• yakapi:ci:result results of executing commands (XADD with the same id as the command)

cam

The camera component can current serve an image if placed in a configured path.

TODO: Redis-ify