WIP: #172 upgrade --major/minor/patch placeholder

cli/recipe/upgrade.go

@@ -29,9 +29,22 @@ semver-like convention. In this case, all possible tags will be listed and it
 is up to the end-user to decide.
 `,
 	ArgsUsage: "<recipe>",
+	Flags: []cli.Flag{
+		PatchFlag,
+		MinorFlag,
+		MajorFlag,
+	},
 	Action: func(c *cli.Context) error {
 		recipe := internal.ValidateRecipe(c)
 
+		bumpType := btoi(Major)*4 + btoi(Minor)*2 + btoi(Patch)
+		if bumpType != 0 {
+			// a bitwise check if the number is a power of 2
+			if (bumpType & (bumpType - 1)) != 0 {
+				logrus.Fatal("you can only use one of: --major, --minor, --patch.")
+			}
+		}
+
 		for _, service := range recipe.Config.Services {
 			catlVersions, err := catalogue.VersionsOfService(recipe.Name, service.Name)
 			if err != nil {
@@ -104,7 +117,18 @@ is up to the end-user to decide.
 			}
 
 			logrus.Debugf("detected compatible upgradable tags '%s' for '%s'", compatibleStrings, service.Name)
-
+			if bumpType != 0 {
+				if bumpType == 1 {
+					// Patch upgrade
+					fmt.Println("Patch")
+				} else if bumpType == 2 {
+					// Minor upgrade
+					fmt.Println("Minor")
+				} else {
+					// Major upgrade
+					fmt.Println("Major")
+				}
+			} else {
 				msg := fmt.Sprintf("upgrade to which tag? (service: %s, tag: %s)", service.Name, tag)
 				if !tagcmp.IsParsable(img.(reference.NamedTagged).Tag()) {
 					tag := img.(reference.NamedTagged).Tag()
@@ -124,11 +148,13 @@ is up to the end-user to decide.
 				if err := survey.AskOne(prompt, &upgradeTag); err != nil {
 					logrus.Fatal(err)
 				}
-
+			}
+			/*
 				if err := recipe.UpdateTag(image, upgradeTag); err != nil {
 					logrus.Fatal(err)
 				}
 				logrus.Debugf("tag updated from '%s' to '%s' for '%s'", image, upgradeTag, recipe.Name)
+			*/
 		}
 
 		return nil