Add git-pull poller

src/pusher/poller/poller.go

@@ -0,0 +1,116 @@
+package poller
+
+import (
+	"time"
+
+	"config"
+	"git"
+	"grafana"
+	"pusher/common"
+
+	"github.com/sirupsen/logrus"
+)
+
+func Setup(cfg *config.Config, client *grafana.Client, delRemoved bool) error {
+	r, needsSync, err := git.NewRepository(cfg.Git)
+	if err != nil {
+		return err
+	}
+
+	if needsSync {
+		if err = r.Sync(false); err != nil {
+			return err
+		}
+	}
+
+	errs := make(chan error, 1)
+
+	go func() {
+		if err = poller(cfg, r, client, delRemoved); err != nil {
+			errs <- err
+			return
+		}
+	}()
+
+	err = <-errs
+	return err
+}
+
+func poller(
+	cfg *config.Config, repo *git.Repository, client *grafana.Client,
+	delRemoved bool,
+) (err error) {
+	latestCommit, err := repo.GetLatestCommit()
+	if err != nil {
+		return
+	}
+
+	previousCommit := latestCommit
+
+	for {
+		addedOrModified := make([]string, 0)
+		removed := make([]string, 0)
+
+		if err = repo.Sync(true); err != nil {
+			return
+		}
+
+		latestCommit, err = repo.GetLatestCommit()
+		if err != nil {
+			return
+		}
+
+		if previousCommit.Hash.String() != latestCommit.Hash.String() {
+			lineCounts, err := git.GetFilesLineCountsAtCommit(previousCommit)
+			if err != nil {
+				return err
+			}
+
+			deltas, err := repo.LineCountsDeltasIgnoreManagerCommits(previousCommit, latestCommit)
+			if err != nil {
+				return err
+			}
+
+			for file, delta := range deltas {
+				if delta == 0 {
+					continue
+				}
+
+				if delta > 0 {
+					addedOrModified = append(addedOrModified, file)
+				} else if delta < 0 {
+					if -delta < lineCounts[file] {
+						addedOrModified = append(addedOrModified, file)
+					} else {
+						removed = append(removed, file)
+					}
+				}
+			}
+		}
+
+		filesToPush := make(map[string][]byte)
+		for _, filename := range addedOrModified {
+			if err = common.PrepareForPush(filename, &filesToPush, cfg); err != nil {
+				return err
+			}
+		}
+
+		common.PushFiles(filesToPush, client)
+
+		if delRemoved {
+			for _, removedFile := range removed {
+				if err = common.DeleteDashboard(
+					removedFile, client, cfg,
+				); err != nil {
+					logrus.WithFields(logrus.Fields{
+						"error":    err,
+						"filename": removedFile,
+					}).Error("Failed to delete the dashboard")
+				}
+			}
+		}
+
+		previousCommit = latestCommit
+		time.Sleep(time.Duration(cfg.Pusher.Config.Interval) * time.Second)
+	}
+}