pkg/utils: Add function to join sets of containers or images in JSON

https://github.com/containers/toolbox/pull/318

src/pkg/utils/utils.go

@@ -159,6 +159,28 @@ func IsInsideToolboxContainer() bool {
 	return false
 }
 
+func JoinJSON(joinkey string, maps ...[]map[string]interface{}) []map[string]interface{} {
+	var json []map[string]interface{}
+	found := make(map[string]bool)
+
+	// Iterate over every json provided and check if it is already in the final json
+	// If it contains some invalid entry (equals nil), then skip that entry
+
+	for _, m := range maps {
+		for _, entry := range m {
+			if entry["names"] == nil && entry["Names"] == nil {
+				continue
+			}
+			key := entry[joinkey].(string)
+			if _, ok := found[key]; !ok {
+				found[key] = true
+				json = append(json, entry)
+			}
+		}
+	}
+	return json
+}
+
 func ShowManual(manual string) error {
 	manBinary, err := exec.LookPath("man")
 	if err != nil {