Squashed commit of the following:

commit f5baab4e88
Author: DaneEveritt <dane@daneeveritt.com>
Date:   Sat Jul 9 17:50:53 2022 -0400

    Finalize activity event sending logic and cron config

commit 9830387f21
Author: DaneEveritt <dane@daneeveritt.com>
Date:   Sat Jul 9 16:26:13 2022 -0400

    Send power events in a more usable format

commit 49f3a61d16
Author: DaneEveritt <dane@daneeveritt.com>
Date:   Sat Jul 9 15:47:24 2022 -0400

    Configure cron to actually send to endpoint

commit 28137c4c14
Author: DaneEveritt <dane@daneeveritt.com>
Date:   Sat Jul 9 15:42:29 2022 -0400

    Copy the body buffer otherwise subsequent backoff attempts will not have a buffer to send

commit 20e44bdc55
Author: DaneEveritt <dane@daneeveritt.com>
Date:   Sat Jul 9 14:38:41 2022 -0400

    Add internal logic to process activity events and send them to the panel

commit 0380488cd2
Author: DaneEveritt <dane@daneeveritt.com>
Date:   Mon Jul 4 17:55:17 2022 -0400

    Track power events

commit 9eab08b92f
Author: DaneEveritt <dane@daneeveritt.com>
Date:   Mon Jul 4 17:36:03 2022 -0400

    Initial logic to support logging activity on Wings to send back to the panel

internal/cron/activity_cron.go

@@ -0,0 +1,98 @@
+package cron
+
+import (
+	"context"
+	"emperror.dev/errors"
+	"github.com/apex/log"
+	"github.com/goccy/go-json"
+	"github.com/pterodactyl/wings/internal/database"
+	"github.com/pterodactyl/wings/server"
+	"github.com/pterodactyl/wings/system"
+	"github.com/xujiajun/nutsdb"
+)
+
+var key = []byte("events")
+var processing system.AtomicBool
+
+func processActivityLogs(m *server.Manager, c int64) error {
+	// Don't execute this cron if there is currently one running. Once this task is completed
+	// go ahead and mark it as no longer running.
+	if !processing.SwapIf(true) {
+		return nil
+	}
+	defer processing.Store(false)
+
+	var list [][]byte
+	err := database.DB().View(func(tx *nutsdb.Tx) error {
+		// Grab the oldest 100 activity events that have been logged and send them back to the
+		// Panel for processing. Once completed, delete those events from the database and then
+		// release the lock on this process.
+		end := int(c)
+		if s, err := tx.LSize(database.ServerActivityBucket, key); err != nil {
+			return errors.WithStackIf(err)
+		} else if s < end || s == 0 {
+			if s == 0 {
+				return nil
+			}
+			end = s
+		}
+		l, err := tx.LRange(database.ServerActivityBucket, key, 0, end)
+		if err != nil {
+			// This error is returned when the bucket doesn't exist, which is likely on the
+			// first invocations of Wings since we haven't yet logged any data. There is nothing
+			// that needs to be done if this error occurs.
+			if errors.Is(err, nutsdb.ErrBucket) {
+				return nil
+			}
+			return errors.WithStackIf(err)
+		}
+		list = l
+		return nil
+	})
+
+	if err != nil || len(list) == 0 {
+		return errors.WithStackIf(err)
+	}
+
+	var processed []json.RawMessage
+	for _, l := range list {
+		var v json.RawMessage
+		if err := json.Unmarshal(l, &v); err != nil {
+			log.WithField("error", errors.WithStack(err)).Warn("failed to parse activity event json, skipping entry")
+			continue
+		}
+		processed = append(processed, v)
+	}
+
+	if err := m.Client().SendActivityLogs(context.Background(), processed); err != nil {
+		return errors.WrapIf(err, "cron: failed to send activity events to Panel")
+	}
+
+	return database.DB().Update(func(tx *nutsdb.Tx) error {
+		if m, err := tx.LSize(database.ServerActivityBucket, key); err != nil {
+			return errors.WithStack(err)
+		} else if m > len(list) {
+			// As long as there are more elements than we have in the length of our list
+			// we can just use the existing `LTrim` functionality of nutsdb. This will remove
+			// all of the values we've already pulled and sent to the API.
+			return errors.WithStack(tx.LTrim(database.ServerActivityBucket, key, len(list), -1))
+		} else {
+			i := 0
+			// This is the only way I can figure out to actually empty the items out of the list
+			// because you cannot use `LTrim` (or I cannot for the life of me figure out how) to
+			// trim the slice down to 0 items without it triggering an internal logic error. Perhaps
+			// in a future release they'll have a function to do this (based on my skimming of issues
+			// on GitHub that I cannot read due to translation barriers).
+			for {
+				if i >= m {
+					break
+				}
+				if _, err := tx.LPop(database.ServerActivityBucket, key); err != nil {
+					return errors.WithStack(err)
+				}
+				i++
+			}
+		}
+		return nil
+	})
+}

internal/cron/cron.go

@@ -0,0 +1,36 @@
+package cron
+
+import (
+	"emperror.dev/errors"
+	"github.com/apex/log"
+	"github.com/go-co-op/gocron"
+	"github.com/pterodactyl/wings/config"
+	"github.com/pterodactyl/wings/server"
+	"github.com/pterodactyl/wings/system"
+	"time"
+)
+
+var o system.AtomicBool
+
+// Scheduler configures the internal cronjob system for Wings and returns the scheduler
+// instance to the caller. This should only be called once per application lifecycle, additional
+// calls will result in an error being returned.
+func Scheduler(m *server.Manager) (*gocron.Scheduler, error) {
+	if o.Load() {
+		return nil, errors.New("cron: cannot call scheduler more than once in application lifecycle")
+	}
+	o.Store(true)
+	l, err := time.LoadLocation(config.Get().System.Timezone)
+	if err != nil {
+		return nil, errors.Wrap(err, "cron: failed to parse configured system timezone")
+	}
+
+	s := gocron.NewScheduler(l)
+	_, _ = s.Tag("activity").Every(config.Get().System.ActivitySendInterval).Seconds().Do(func() {
+		if err := processActivityLogs(m, config.Get().System.ActivitySendCount); err != nil {
+			log.WithField("error", err).Error("cron: failed to process activity events")
+		}
+	})
+
+	return s, nil
+}

internal/database/database.go

@@ -0,0 +1,38 @@
+package database
+
+import (
+	"emperror.dev/errors"
+	"github.com/apex/log"
+	"github.com/pterodactyl/wings/config"
+	"github.com/xujiajun/nutsdb"
+	"path/filepath"
+	"sync"
+)
+
+var db *nutsdb.DB
+var syncer sync.Once
+
+const (
+	ServerActivityBucket = "server_activity"
+)
+
+func initialize() error {
+	opt := nutsdb.DefaultOptions
+	opt.Dir = filepath.Join(config.Get().System.RootDirectory, "db")
+
+	instance, err := nutsdb.Open(opt)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+	db = instance
+	return nil
+}
+
+func DB() *nutsdb.DB {
+	syncer.Do(func() {
+		if err := initialize(); err != nil {
+			log.WithField("error", err).Fatal("database: failed to initialize instance, this is an unrecoverable error")
+		}
+	})
+	return db
+}