recipe/upgrade: Refactor upgradability list to make output easier

For future, we can print the struct as JSON.

cli/recipe/upgrade.go

@@ -27,6 +27,13 @@ type imgPin struct {
 	version tagcmp.Tag
 }
 
+type upgradeList struct {
+	service     string
+	image       string
+	tag         string
+	upgradeTags []string
+}
+
 var recipeUpgradeCommand = cli.Command{
 	Name:    "upgrade",
 	Aliases: []string{"u"},
@@ -75,6 +82,8 @@ You may invoke this command in "wizard" mode and be prompted for input:
 			}
 		}
 
+		var upgrades []upgradeList
+
 		// check for versions file and load pinned versions
 		versionsPresent := false
 		recipeDir := path.Join(config.RECIPES_DIR, recipe.Name)
@@ -240,11 +249,25 @@ You may invoke this command in "wizard" mode and be prompted for input:
 							compatibleStrings = append(compatibleStrings, regVersion)
 						}
 					}
-					if internal.NoInput {
-						logrus.Infof("potential upgrades for service: %s, image: %s, tag: %s ::\t", service.Name, image, tag)
-						for _, upgradableVersion := range compatibleStrings[1:] {
-							logrus.Infof("\t%s\n", upgradableVersion)
+
+					upgrade := upgradeList{
+						service:     service.Name,
+						image:       image,
+						tag:         tag.String(),
+						upgradeTags: make([]string, len(compatibleStrings[1:])),
+					}
+
+					for n, s := range compatibleStrings[1:] {
+						var sb strings.Builder
+						if _, err := sb.WriteString(s); err != nil {
 						}
+						upgrade.upgradeTags[n] = sb.String()
+					}
+
+					upgrades = append(upgrades, upgrade)
+
+					if internal.NoInput {
+						upgradeTag = "skip"
 					} else {
 						prompt := &survey.Select{
 							Message: msg,
@@ -267,10 +290,21 @@ You may invoke this command in "wizard" mode and be prompted for input:
 					logrus.Infof("tag upgraded from %s to %s for %s", tag.String(), upgradeTag, image)
 				}
 			} else {
-				logrus.Warnf("not upgrading %s, skipping as requested", image)
+				if !internal.NoInput {
+					logrus.Warnf("not upgrading %s, skipping as requested", image)
+				}
 			}
 		}
 
+		if internal.NoInput {
+			// FIXME handle machine-readable here
+			for _, upgrade := range upgrades {
+				logrus.Infof("can upgrade service: %s, image: %s, tag: %s ::\n", upgrade.service, upgrade.image, upgrade.tag)
+				for _, utag := range upgrade.upgradeTags {
+					logrus.Infof("    %s\n", utag)
+				}
+			}
+		}
 		return nil
 	},
 }