chore: remove some duplication and add a first few tests

kube/collector.go

@@ -0,0 +1,30 @@
+package kube
+
+import "strings"
+
+type ImageCollector map[string]map[string]struct{}
+
+func NewImageCollector() ImageCollector {
+	return make(map[string]map[string]struct{})
+}
+
+func (c *ImageCollector) Add(image string) {
+	parts := strings.Split(image[20:], ":")
+	if x, exists := (*c)[parts[0]]; exists {
+		x[parts[1]] = struct{}{}
+	} else {
+		(*c)[parts[0]] = map[string]struct{}{
+			parts[1]: {},
+		}
+	}
+}
+
+func (c *ImageCollector) Images() map[string][]string {
+	images := make(map[string][]string)
+	for i, x := range *c {
+		for v := range x {
+			images[i] = append(images[i], v)
+		}
+	}
+	return images
+}