fork: wait for the actual fork process completion

Today, `lab fork` doesn't check if the fork on Gitlab system is indeed
finished, it just assumes so and move on. However, some projects are big
enough to not satisfy it, for instance: the linux kernel. A project
containing the linux kernel source code may take _minutes_ to fork, and the
user will be prompted with an error if the "clone" is not skipped with
--skip-clone.

This patch forces the `lab fork` command to wait the fork completion on
Gitlab system and also adds the "--no-wait" flag if the user really don't
want to wait for anything.

Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>

cmd/fork.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"fmt"
 	"log"
 	"strings"
 
@@ -10,8 +11,11 @@ import (
 	lab "github.com/zaquestion/lab/internal/gitlab"
 )
 
-var skipClone = false
-var forkData lab.ForkStruct
+var (
+	skipClone = false
+	waitFork  = true
+	forkData  lab.ForkStruct
+)
 
 // forkCmd represents the fork command
 var forkCmd = &cobra.Command{
@@ -22,6 +26,8 @@ var forkCmd = &cobra.Command{
 	PersistentPreRun: LabPersistentPreRun,
 	Run: func(cmd *cobra.Command, args []string) {
 		skipClone, _ = cmd.Flags().GetBool("skip-clone")
+		noWaitFork, _ := cmd.Flags().GetBool("no-wait")
+		waitFork = !noWaitFork
 		forkData.TargetName, _ = cmd.Flags().GetString("name")
 		forkData.TargetNamespace, _ = cmd.Flags().GetString("namespace")
 		forkData.TargetPath, _ = cmd.Flags().GetString("path")
@@ -60,9 +66,13 @@ func forkFromOrigin(cmd *cobra.Command, args []string) {
 		log.Fatal(err)
 	}
 	forkData.SrcProject = project
-	forkRemoteURL, err := lab.Fork(forkData, useHTTP)
+	forkRemoteURL, err := lab.Fork(forkData, useHTTP, waitFork)
 	if err != nil {
-		log.Fatal(err)
+		if err.Error() == "not finished" {
+			fmt.Println("This fork is not ready yet and might take some minutes.")
+		} else {
+			log.Fatal(err)
+		}
 	}
 
 	name := determineForkRemote(project)
@@ -75,9 +85,14 @@ func forkToUpstream(cmd *cobra.Command, args []string) {
 	forkData.SrcProject = args[0]
 	// lab.Fork doesn't have access to the useHTTP var, so we need to pass
 	// this info to that, so the process works correctly.
-	_, err := lab.Fork(forkData, useHTTP)
+	_, err := lab.Fork(forkData, useHTTP, waitFork)
 	if err != nil {
-		log.Fatal(err)
+		if err.Error() == "not finished" && !skipClone {
+			fmt.Println("This fork is not ready yet and might take some minutes.")
+			skipClone = true
+		} else {
+			log.Fatal(err)
+		}
 	}
 
 	if !skipClone {
@@ -112,6 +127,7 @@ func determineForkRemote(project string) string {
 
 func init() {
 	forkCmd.Flags().BoolP("skip-clone", "s", false, "skip clone after remote fork")
+	forkCmd.Flags().Bool("no-wait", false, "don't wait for forking operation to finish")
 	forkCmd.Flags().StringP("name", "n", "", "fork project with a different name")
 	forkCmd.Flags().StringP("namespace", "m", "", "fork project in a different namespace")
 	forkCmd.Flags().StringP("path", "p", "", "fork project with a different path")

internal/gitlab/gitlab.go

@@ -224,7 +224,7 @@ func (fs ForkStruct) isCustomTargetSet() bool {
 }
 
 // Fork creates a user fork of a GitLab project using the specified protocol
-func Fork(data ForkStruct, useHTTP bool) (string, error) {
+func Fork(data ForkStruct, useHTTP bool, wait bool) (string, error) {
 	if !strings.Contains(data.SrcProject, "/") {
 		return "", errors.New("remote must include namespace")
 	}
@@ -247,6 +247,10 @@ func Fork(data ForkStruct, useHTTP bool) (string, error) {
 		return "", err
 	}
 
+	// Now that we have the "wait" opt, don't let the user in the hope that
+	// something is running.
+	fmt.Printf("Forking %s project...\n", data.SrcProject)
+
 	var forkOpts *gitlab.ForkProjectOptions = nil
 	if data.isCustomTargetSet() {
 		forkOpts = &gitlab.ForkProjectOptions{
@@ -260,11 +264,31 @@ func Fork(data ForkStruct, useHTTP bool) (string, error) {
 		return "", err
 	}
 
+	// Busy-wait approach for checking the import_status of the fork.
+	// References:
+	//   https://docs.gitlab.com/ce/api/projects.html#fork-project
+	//   https://docs.gitlab.com/ee/api/project_import_export.html#import-status
+	status, _, err := lab.ProjectImportExport.ImportStatus(fork.ID, nil)
+	if wait {
+		for {
+			if status.ImportStatus == "finished" {
+				break
+			}
+			status, _, err = lab.ProjectImportExport.ImportStatus(fork.ID, nil)
+			if err != nil {
+				log.Fatal(err)
+			}
+			time.Sleep(2 * time.Second)
+		}
+	} else if status.ImportStatus != "finished" {
+		err = errors.New("not finished")
+	}
+
 	urlToRepo := fork.SSHURLToRepo
 	if useHTTP {
 		urlToRepo = fork.HTTPURLToRepo
 	}
-	return urlToRepo, nil
+	return urlToRepo, err
 }
 
 // MRCreate opens a merge request on GitLab