Remove sort interface

main.go

@@ -15,9 +15,11 @@ import (
 	dockerClient "github.com/docker/docker/client"
 )
 
+// Default values for fetching tags from registry
 var registryBase = "https://registry.hub.docker.com"
 var maxPages = 10
 
+// Regexp used to extract tag information
 var tagRegexp = regexp.MustCompile(`(.*):[vV]{0,1}([0-9.]+)(-(.*)){0,1}`)
 
 // ImageTag is wraps an image and tag values for a container
@@ -93,24 +95,6 @@ func ParseImageTag(imageTag string) (ImageTag, error) {
 	}, nil
 }
 
-// ImageTagSort is an interface for sorting ImageTags
-type ImageTagSort []ImageTag
-
-// Len gives the length of the image sorter interface
-func (slice ImageTagSort) Len() int {
-	return len(slice)
-}
-
-// Less returns true if the first value is less than or equal to the second
-func (slice ImageTagSort) Less(i, j int) bool {
-	return slice[i].CompareTo(slice[j]) == -1
-}
-
-// Swap two values in slice
-func (slice ImageTagSort) Swap(i, j int) {
-	slice[i], slice[j] = slice[j], slice[i]
-}
-
 func getJSON(url string, response interface{}) error {
 	resp, err := http.Get(url)
 	if err != nil {
@@ -177,18 +161,20 @@ func getNewerTags(current ImageTag) ([]ImageTag, error) {
 		}
 	}
 	// Sort tags with newest first
-	sort.Sort(sort.Reverse(ImageTagSort(newerTags)))
+	sort.Slice(newerTags, func(i, j int) bool { return newerTags[i].CompareTo(newerTags[j]) == 1 })
 	return newerTags, nil
 }
 
 func main() {
 	dockerClient, err := dockerClient.NewClientWithOpts(dockerClient.FromEnv)
 	if err != nil {
+		fmt.Println("Could not initialize docker client")
 		panic(err)
 	}
 
 	containers, err := dockerClient.ContainerList(context.Background(), dockerTypes.ContainerListOptions{})
 	if err != nil {
+		fmt.Println("Could list container from docker client")
 		panic(err)
 	}