index.js

/*
 * Copyright 2024 SeB (sebba@end.ro) - S/V Haimana 264900475
 * 
 * Plugin page:
 * 
 * https://github.com/haimana/signalk-rpi-uptime
 * 
 * This plugin has been inspired and based on:
 * https://github.com/sbender9/signalk-raspberry-pi-temperature
 * and
 * https://github.com/sberl/signalk-rpi-monitor
 * 
 * Many thanks to the authors: Scott Bender and Steve Berl
 * 
 * ---------------------------------------------------------------------
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0

 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
*/

const _ = require('lodash')
const spawn = require('child_process').spawn
const command = 'cat /proc/uptime'

module.exports = function(app) {
  var plugin = {};
  let timer = null

  plugin.id = "signalk-rpi-uptime"
  plugin.name = "RPi Uptime"
  plugin.description = "SignalK Node Server Plugin to provide Raspberry Pi Uptime"
  plugin.schema = {
    type: "object",
    properties: {
      path_seconds: {
        title: "SignalK Path (seconds)",
        type: "string",
        default: "environment.rpi.uptime",
      },
      prettyenable: {
        type: 'boolean',
        title: 'Enable pretty report',
        default: false
      },      
      path_pretty: {
        title: "SignalK Path (pretty)",
        type: "string",
        default: "environment.rpi.uptimepretty",
      },
      rate: {
        title: "Sample Rate (in seconds)",
        type: 'number',
        default: 60
      }
     }
  }

  plugin.start = function(options) {

    app.handleMessage(plugin.id, {
        updates: [{
            meta: [
                {
                    path: options.path_seconds,
                    value: {
                        units: "s"
                    }
                }
            ]
        }]
    });
	
    function printUptime() {
      var seconds = spawn('sh', ['-c', command ])
      seconds.stdout.on('data', (data) => {
          app.debug(`Output of "${command}":  ${data}`)
          var uptimeseconds = data.toString().split('.')[0];
          app.debug(`Processed string:  ${uptimeseconds}`)
          app.debug(`Pretty enabled: ${options.prettyenable}`)

          if (options.prettyenable) {
            app.handleMessage(plugin.id, {
              updates: [
                  {
                    values: [ 
                      {
                        path: options.path_seconds,
                        value: parseInt(uptimeseconds)
                      },
                      { 
                        path: options.path_pretty,
                        value: secondsToDhms(uptimeseconds)
                      }
                    ]
                  }
                ]
            })
          } else {
            app.handleMessage(plugin.id, {
              updates: [
                  {
                    values: [ 
                      {
                        path: options.path_seconds,
                        value: parseInt(uptimeseconds)
                      }
                    ]
                  }
                ]
            })
          }
         })

      seconds.on('error', (error) => { console.error(error.toString()) })
      seconds.stderr.on('data', function (data) { console.error(data.toString()) })
    }

    timer=setInterval(printUptime, options.rate * 1000)
  }
  

  plugin.stop = function() {
    if ( timer ) {
      clearInterval(timer)
      timer =  null
    }
  }

  return plugin
}


//additional functions

function secondsToDhms(seconds) {
  seconds = Number(seconds);
  var d = Math.floor(seconds / (3600*24));
  var h = Math.floor(seconds % (3600*24) / 3600);
  var m = Math.floor(seconds % 3600 / 60);
  var s = Math.floor(seconds % 60);
  
  var dDisplay = d > 0 ? d + (d == 1 ? " day, " : " days, ") : "";
  var hDisplay = h > 0 ? h + (h == 1 ? " hour, " : " hours, ") : "";
  var mDisplay = m > 0 ? m + (m == 1 ? " minute, " : " minutes, ") : "";
  var sDisplay = s > 0 ? s + (s == 1 ? " second" : " seconds") : "";
  return dDisplay + hDisplay + mDisplay + sDisplay;
  }