servermanager/src/main/java/de/gurkengewuerz/monitoring/Poller.java

package de.gurkengewuerz.monitoring;

import de.gurkengewuerz.monitoring.object.SSHManager;
import de.gurkengewuerz.monitoring.object.Server;
import de.gurkengewuerz.monitoring.object.ServerStatus;
import de.gurkengewuerz.monitoring.object.State;
import org.pmw.tinylog.Logger;

import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.text.NumberFormat;
import java.text.ParseException;
import java.util.HashMap;
import java.util.Locale;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

/**
 * Created by gurkengewuerz.de on 21.10.2017.
 */
public class Poller {
    final ScheduledExecutorService scheduler;

    public Poller() {
        scheduler = Executors.newScheduledThreadPool(1);
        if (!StartUp.getPrivateKey().exists()) {
            Logger.error(StartUp.getPrivateKey().getPath() + " wurde nicht gefunden!");
            return;
        }
        scheduler.scheduleAtFixedRate(() -> {
            HashMap<String, Server> serverlist = Server.getServerList(StartUp.getDb());

            serverlist.forEach((s, server) -> {
                Logger.info("Poling " + s);
                ServerStatus status = server.getStatus();
                if (status.getState() == State.PAUSED) {
                    Logger.info("Paused!");
                    return;
                }
                SSHManager manager = server.getSSHSession(StartUp.getPrivateKey());
                if (manager.hasError()) {
                    status.setState(State.OFFLINE);
                    Logger.error("Offline!");

                    try {
                        if (status.getLastpoll() == 0) return;
                        PreparedStatement ps = StartUp.getDb().getPreparedStatement("UPDATE status SET state = ?, lastpoll = ? WHERE server_id = ?;");
                        ps.setString(1, status.getState().toString());
                        ps.setLong(2, System.currentTimeMillis() / 1000);
                        ps.setInt(3, server.getId());
                        ps.execute();
                    } catch (SQLException e) {
                        Logger.error(e);
                    }
                    status.setLastpoll(System.currentTimeMillis() / 1000);
                    return;
                }

                try {
                    status.setState(State.ONLINE);
                    Logger.info("Online!");

                    NumberFormat format = NumberFormat.getInstance(Locale.US);
                    String os = manager.sendCommand(". /etc/os-release; echo ${PRETTY_NAME/*, /}").replace("\n", "");
                    status.setOS(os);
                    String cpumodel = manager.sendCommand("grep \"model name\" /proc/cpuinfo | cut -c14- | head -n 1").replace("\n", "");
                    status.setCPU(cpumodel);
                    String cpucount = manager.sendCommand("cat /proc/cpuinfo | grep processor | wc -l").replace("\n", "");
                    status.setCPUcount(format.parse(cpucount).intValue());
                    String memtotal = manager.sendCommand("awk '/MemTotal/ { print $2 }' /proc/meminfo").replace("\n", "");
                    status.setMemTotal(format.parse(memtotal).intValue());
                    String memfree = manager.sendCommand("awk '/MemFree/ { print $2 }' /proc/meminfo").replace("\n", "");
                    status.setMemFree(format.parse(memfree).intValue());
                    String load = manager.sendCommand("if [[ -z `uptime | awk '{print $12}' | cut -d \",\" -f 1` ]]; then uptime | awk '{print $10}' | cut -d \",\" -f 1; else uptime | awk '{print $12}' | cut -d \",\" -f 1; fi;").replace("\n", "");
                    status.setLoad(format.parse(load).floatValue());
                    String uptimeseconds = manager.sendCommand("awk '{print $1}' /proc/uptime").replace("\n", "");
                    status.setUptime(format.parse(uptimeseconds).longValue());

                    try {
                        PreparedStatement ps = StartUp.getDb().getPreparedStatement("UPDATE status SET os = ?, cpu = ?, cpucount = ?, max_ram = ?, current_ram = ?, load = ?, uptime = ?, state = ?, lastpoll = ? WHERE server_id = ?;");
                        if (status.getLastpoll() == 0) {
                            ps = StartUp.getDb().getPreparedStatement("INSERT INTO status (os, cpu, cpucount, max_ram, current_ram, load, uptime, state, lastpoll, server_id) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?);");

                        }
                        ps.setString(1, os);
                        ps.setString(2, cpumodel);
                        ps.setInt(3, format.parse(cpucount).intValue());
                        ps.setInt(4, format.parse(memtotal).intValue());
                        ps.setInt(5, format.parse(memfree).intValue());
                        ps.setFloat(6, format.parse(load).floatValue());
                        ps.setLong(7, format.parse(uptimeseconds).longValue());
                        ps.setString(8, status.getState().toString());
                        ps.setLong(9, System.currentTimeMillis() / 1000);
                        ps.setInt(10, server.getId());
                        ps.execute();
                    } catch (SQLException e) {
                        Logger.error(e);
                    }

                    status.setLastpoll(System.currentTimeMillis() / 1000);
                } catch (ParseException e) {
                    Logger.error(e);
                }
                manager.close();
            });
        }, 0, 90, TimeUnit.SECONDS);
    }

    public void stop() {
        scheduler.shutdown();
    }
}