internal/dis: Add 'watcher' component for infos

internal/dis/component/watcher.go

@@ -0,0 +1,34 @@
+package component
+
+import (
+	"time"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/config"
+	"github.com/FAU-CDI/wisski-distillery/internal/models"
+)
+
+// Observer is a component with an Observe method
+type Observer interface {
+	Component
+
+	// Observe observes this distillery component and writes the result into observation
+	// Distinct Observers must write into distinct fields.
+	Observe(flags ObservationFlags, observation *Observation) error
+}
+
+type ObservationFlags struct{}
+
+// Observation represents fetched information about the distillery
+type Observation struct {
+	Time time.Time // Time this obervation was built
+
+	// Configuration of the distillery
+	Config *config.Config
+
+	// number of instances
+	TotalCount   int
+	RunningCount int
+	StoppedCount int
+
+	Backups []models.Export // list of backups
+}