chore(cmd/cli): Reduce cyclomatic complexity of uninstall command (openservicemesh#4825)

* chore(cmd/cli): Reduce cyclomatic complexity of uninstall command

Separate code into functions to reduce the cyclomatic complexity
And adds unit tests to functions created
Helps unblock openservicemesh#4555

Signed-off-by: Shalier Xia <[email protected]>

Author: shalier

cmd/cli/uninstall_mesh.go

@@ -74,18 +74,18 @@ func newUninstallMeshCmd(config *action.Configuration, in io.Reader, out io.Writ
 			// get kubeconfig and initialize k8s client
 			kubeconfig, err := settings.RESTClientGetter().ToRESTConfig()
 			if err != nil {
-				return errors.Errorf("Error fetching kubeconfig: %s", err)
+				return fmt.Errorf("Error fetching kubeconfig: %s", err)
 			}
 			uninstall.config = kubeconfig
 
 			uninstall.clientSet, err = kubernetes.NewForConfig(kubeconfig)
 			if err != nil {
-				return errors.Errorf("Could not access Kubernetes cluster, check kubeconfig: %s", err)
+				return fmt.Errorf("Could not access Kubernetes cluster, check kubeconfig: %s", err)
 			}
 
 			uninstall.extensionsClientset, err = extensionsClientset.NewForConfig(kubeconfig)
 			if err != nil {
-				return errors.Errorf("Could not access extension client set: %s", err)
+				return fmt.Errorf("Could not access extension client set: %s", err)
 			}
 
 			uninstall.meshNamespace = settings.Namespace()
@@ -118,10 +118,10 @@ func (d *uninstallMeshCmd) run() error {
 			fmt.Fprintf(d.out, "No OSM control planes found\n")
 			return nil
 		}
-		// Searches for the mesh specified by the mesh-name flag if specified
-		specifiedMeshFound := false
-		if d.meshName != "" {
-			specifiedMeshFound = d.findMesh(meshInfoList)
+
+		if d.meshSpecified() {
+			// Searches for the mesh specified by the mesh-name flag if specified
+			specifiedMeshFound := d.findSpecifiedMesh(meshInfoList)
 			if !specifiedMeshFound {
 				return nil
 			}
@@ -143,19 +143,11 @@ func (d *uninstallMeshCmd) run() error {
 				return err
 			}
 			// Prompts user on whether to uninstall each OSM mesh in the cluster
-			for _, mesh := range meshInfoList {
-				// Only prompt for specified mesh if `mesh-name` is specified
-				if specifiedMeshFound && mesh.name != d.meshName {
-					continue
-				}
-				confirm, err := confirm(d.in, d.out, fmt.Sprintf("\nUninstall OSM [mesh name: %s] in namespace [%s] and/or OSM resources?", mesh.name, mesh.namespace), 3)
-				if err != nil {
-					return err
-				}
-				if confirm {
-					meshesToUninstall = append(meshesToUninstall, mesh)
-				}
+			uninstallMeshes, err := d.promptMeshUninstall(meshInfoList, meshesToUninstall)
+			if err != nil {
+				return err
 			}
+			meshesToUninstall = append(meshesToUninstall, uninstallMeshes...)
 		}
 
 		for _, m := range meshesToUninstall {
@@ -175,22 +167,16 @@ func (d *uninstallMeshCmd) run() error {
 					return err
 				}
 
-				fmt.Fprintf(d.out, "Error %v when trying to uninstall mesh name [%s] in namespace [%s] - continuing to deleteClusterWideResources and/or deleteNamespace\n", err, m.name, m.namespace)
+				fmt.Fprintf(d.out, "Could not uninstall mesh name [%s] in namespace [%s]- %v - continuing to deleteClusterWideResources and/or deleteNamespace\n", m.name, m.namespace, err)
 			}
 
 			if err == nil {
 				fmt.Fprintf(d.out, "OSM [mesh name: %s] in namespace [%s] uninstalled\n", m.name, m.namespace)
 			}
 
-			if d.deleteNamespace {
-				if err := d.clientSet.CoreV1().Namespaces().Delete(ctx, m.namespace, v1.DeleteOptions{}); err != nil {
-					if k8sApiErrors.IsNotFound(err) {
-						fmt.Fprintf(d.out, "OSM namespace [%s] not found\n", m.namespace)
-						return nil
-					}
-					return errors.Errorf("Error occurred while deleting OSM namespace [%s] - %v", m.namespace, err)
-				}
-				fmt.Fprintf(d.out, "OSM namespace [%s] deleted successfully\n", m.namespace)
+			err = d.deleteNs(ctx, m.namespace)
+			if err != nil {
+				return err
 			}
 		}
 	} else {
@@ -199,6 +185,61 @@ func (d *uninstallMeshCmd) run() error {
 			fmt.Fprintf(d.out, "OSM namespace CANNOT be deleted in a managed environment\n")
 		}
 	}
+
+	err := d.deleteClusterResources()
+	return err
+}
+
+func (d *uninstallMeshCmd) meshSpecified() bool {
+	return d.meshName != ""
+}
+
+func (d *uninstallMeshCmd) findSpecifiedMesh(meshInfoList []meshInfo) bool {
+	specifiedMeshFound := d.findMesh(meshInfoList)
+	if !specifiedMeshFound {
+		fmt.Fprintf(d.out, "Did not find mesh [%s] in namespace [%s]\n", d.meshName, d.meshNamespace)
+		// print a list of meshes within the cluster for a better user experience
+		if err := d.printMeshes(); err != nil {
+			fmt.Fprintf(d.out, "Unable to list meshes in the cluster - [%v]", err)
+		}
+	}
+
+	return specifiedMeshFound
+}
+
+func (d *uninstallMeshCmd) promptMeshUninstall(meshInfoList, meshesToUninstall []meshInfo) ([]meshInfo, error) {
+	for _, mesh := range meshInfoList {
+		// Only prompt for specified mesh if `mesh-name` is specified
+		if d.meshSpecified() && mesh.name != d.meshName {
+			continue
+		}
+		confirm, err := confirm(d.in, d.out, fmt.Sprintf("\nUninstall OSM [mesh name: %s] in namespace [%s] and/or OSM resources?", mesh.name, mesh.namespace), 3)
+		if err != nil {
+			return nil, err
+		}
+		if confirm {
+			meshesToUninstall = append(meshesToUninstall, mesh)
+		}
+	}
+	return meshesToUninstall, nil
+}
+
+func (d *uninstallMeshCmd) deleteNs(ctx context.Context, ns string) error {
+	if !d.deleteNamespace {
+		return nil
+	}
+	if err := d.clientSet.CoreV1().Namespaces().Delete(ctx, ns, v1.DeleteOptions{}); err != nil {
+		if k8sApiErrors.IsNotFound(err) {
+			fmt.Fprintf(d.out, "OSM namespace [%s] not found\n", ns)
+			return nil
+		}
+		return fmt.Errorf("Could not delete OSM namespace [%s] - %v", ns, err)
+	}
+	fmt.Fprintf(d.out, "OSM namespace [%s] deleted successfully\n", ns)
+	return nil
+}
+
+func (d *uninstallMeshCmd) deleteClusterResources() error {
 	if d.deleteClusterWideResources {
 		meshInfoList, err := getMeshInfoList(d.config, d.clientSet)
 		if err != nil {
@@ -213,10 +254,9 @@ func (d *uninstallMeshCmd) run() error {
 
 		failedDeletions := d.uninstallClusterResources()
 		if len(failedDeletions) != 0 {
-			return errors.Errorf("Failed to completely delete the following OSM resource types: %+v", failedDeletions)
+			return fmt.Errorf("Failed to completely delete the following OSM resource types: %+v", failedDeletions)
 		}
 	}
-
 	return nil
 }
 
@@ -278,7 +318,7 @@ func (d *uninstallMeshCmd) uninstallCustomResourceDefinitions() error {
 	}
 
 	if len(failedDeletions) != 0 {
-		return errors.Errorf("Failed to delete the following OSM CRDs: %+v", failedDeletions)
+		return fmt.Errorf("Failed to delete the following OSM CRDs: %+v", failedDeletions)
 	}
 
 	return nil
@@ -325,7 +365,7 @@ func (d *uninstallMeshCmd) uninstallMutatingWebhookConfigurations() error {
 	}
 
 	if len(failedDeletions) != 0 {
-		return errors.Errorf("Found but failed to delete the following OSM MutatingWebhookConfigurations: %+v", failedDeletions)
+		return fmt.Errorf("Found but failed to delete the following OSM MutatingWebhookConfigurations: %+v", failedDeletions)
 	}
 
 	return nil
@@ -373,7 +413,7 @@ func (d *uninstallMeshCmd) uninstallValidatingWebhookConfigurations() error {
 	}
 
 	if len(failedDeletions) != 0 {
-		return errors.Errorf("Found but failed to delete the following OSM ValidatingWebhookConfigurations: %+v", failedDeletions)
+		return fmt.Errorf("Found but failed to delete the following OSM ValidatingWebhookConfigurations: %+v", failedDeletions)
 	}
 
 	return nil
@@ -407,7 +447,7 @@ func (d *uninstallMeshCmd) uninstallSecrets() error {
 	}
 
 	if len(failedDeletions) != 0 {
-		return errors.Errorf("Found but failed to delete the following OSM secrets in namespace %s: %+v", d.meshNamespace, failedDeletions)
+		return fmt.Errorf("Found but failed to delete the following OSM secrets in namespace %s: %+v", d.meshNamespace, failedDeletions)
 	}
 
 	return nil
@@ -422,17 +462,7 @@ func (d *uninstallMeshCmd) findMesh(meshInfoList []meshInfo) bool {
 			break
 		}
 	}
-	if found {
-		return true
-	}
-
-	fmt.Fprintf(d.out, "Did not find mesh [%s] in namespace [%s]\n", d.meshName, d.meshNamespace)
-	// print a list of meshes within the cluster for a better user experience
-	err := d.printMeshes()
-	if err != nil {
-		fmt.Fprintf(d.out, "Unable to list meshes in the cluster - [%v]", err)
-	}
-	return false
+	return found
 }
 
 // printMeshes prints list of meshes within the cluster for a better user experience