upload/pulp: wait for tasks in UploadAndDistributeCommit

When uploading and distributing a commit, wait for any async tasks to
finish before returning.  There are two tasks that can block this
function:
- Creating a distribution: this only happens when a new repository is
  created.
- Import commit: this will always happen in this function.

internal/upload/pulp/pulp.go

@@ -7,6 +7,8 @@ import (
 	"io"
 	"net/http"
 	"os"
+	"sync"
+	"time"
 
 	"github.com/osbuild/pulp-client/pulpclient"
 	"github.com/sirupsen/logrus"
@@ -247,6 +249,26 @@ func (cl *Client) TaskWaitingOrRunning(task string) bool {
 	return state == TASK_RUNNING || state == TASK_WAITING
 }
 
+// Block until all tasks are complete.
+func (cl *Client) waitFor(tasks []string) {
+	wg := sync.WaitGroup{}
+	logrus.Info("setting up wait group")
+	for idx := range tasks {
+		task := tasks[idx]
+		logrus.Infof("task %q", task)
+		wg.Add(1)
+		go func() {
+			logrus.Infof("waiting for task %q to finish", task)
+			for cl.TaskWaitingOrRunning(task) {
+				time.Sleep(15 * time.Second)
+			}
+			logrus.Infof("task %q done", task)
+			wg.Done()
+		}()
+	}
+	wg.Wait()
+}
+
 // UploadAndDistributeCommit uploads a commit, creates a repository if
 // necessary, imports the commit to the repository, and distributes the
 // repository.
@@ -273,6 +295,8 @@ func (cl *Client) UploadAndDistributeCommit(archivePath, repoName, basePath stri
 		return "", err
 	}
 
+	tasks := make([]string, 0)
+
 	if repoHref == "" {
 		// repository does not exist: create it and distribute
 		logrus.Infof("repository not found - creating repository %q", repoName)
@@ -284,15 +308,22 @@ func (cl *Client) UploadAndDistributeCommit(archivePath, repoName, basePath stri
 		repoHref = href
 		logrus.Infof("created repository %q (%s)", repoName, repoHref)
 		logrus.Infof("creating distribution at %q", basePath)
-		if _, err := cl.DistributeOSTreeRepo(basePath, repoName, repoHref); err != nil {
+		distTask, err := cl.DistributeOSTreeRepo(basePath, repoName, repoHref)
+		if err != nil {
 			return "", err
 		}
+		tasks = append(tasks, distTask)
 	}
 
 	logrus.Infof("importing commit %q to repo %q", fileHref, repoHref)
-	if _, err := cl.ImportCommit(fileHref, repoHref); err != nil {
+	importTask, err := cl.ImportCommit(fileHref, repoHref)
+	if err != nil {
 		return "", err
 	}
+	tasks = append(tasks, importTask)
+
+	logrus.Infof("blocking on %d tasks", len(tasks))
+	cl.waitFor(tasks)
 
 	repoURL, err := cl.GetDistributionURLForOSTreeRepo(repoHref)
 	if err != nil {