feat(notifications): add json template (#1542)

pkg/notifications/json.go

@@ -0,0 +1,71 @@
+package notifications
+
+import (
+	"encoding/json"
+
+	t "github.com/containrrr/watchtower/pkg/types"
+)
+
+type jsonMap = map[string]interface{}
+
+// MarshalJSON implements json.Marshaler
+func (d Data) MarshalJSON() ([]byte, error) {
+	var entries = make([]jsonMap, len(d.Entries))
+	for i, entry := range d.Entries {
+		entries[i] = jsonMap{
+			`level`:   entry.Level,
+			`message`: entry.Message,
+			`data`:    entry.Data,
+			`time`:    entry.Time,
+		}
+	}
+
+	var report jsonMap
+	if d.Report != nil {
+		report = jsonMap{
+			`scanned`: marshalReports(d.Report.Scanned()),
+			`updated`: marshalReports(d.Report.Updated()),
+			`failed`:  marshalReports(d.Report.Failed()),
+			`skipped`: marshalReports(d.Report.Skipped()),
+			`stale`:   marshalReports(d.Report.Stale()),
+			`fresh`:   marshalReports(d.Report.Fresh()),
+		}
+	}
+
+	return json.Marshal(jsonMap{
+		`report`:  report,
+		`title`:   d.Title,
+		`host`:    d.Host,
+		`entries`: entries,
+	})
+}
+
+func marshalReports(reports []t.ContainerReport) []jsonMap {
+	jsonReports := make([]jsonMap, len(reports))
+	for i, report := range reports {
+		jsonReports[i] = jsonMap{
+			`id`:             report.ID().ShortID(),
+			`name`:           report.Name(),
+			`currentImageId`: report.CurrentImageID().ShortID(),
+			`latestImageId`:  report.LatestImageID().ShortID(),
+			`imageName`:      report.ImageName(),
+			`state`:          report.State(),
+		}
+		if errorMessage := report.Error(); errorMessage != "" {
+			jsonReports[i][`error`] = errorMessage
+		}
+	}
+	return jsonReports
+}
+
+var _ json.Marshaler = &Data{}
+
+func toJSON(v interface{}) string {
+	var bytes []byte
+	var err error
+	if bytes, err = json.MarshalIndent(v, "", "  "); err != nil {
+		LocalLog.Errorf("failed to marshal JSON in notification template: %v", err)
+		return ""
+	}
+	return string(bytes)
+}