fix deletion of pr env workflow files

api/server/handlers/environment/delete.go

@@ -1,6 +1,8 @@
 package environment
 
 import (
+	"errors"
+	"fmt"
 	"net/http"
 
 	"github.com/porter-dev/porter/api/server/authz"
@@ -58,22 +60,6 @@ func (c *DeleteEnvironmentHandler) ServeHTTP(w http.ResponseWriter, r *http.Requ
 		return
 	}
 
-	err = actions.DeleteEnv(&actions.EnvOpts{
-		Client:            client,
-		ServerURL:         c.Config().ServerConf.ServerURL,
-		GitRepoOwner:      env.GitRepoOwner,
-		GitRepoName:       env.GitRepoName,
-		ProjectID:         project.ID,
-		ClusterID:         cluster.ID,
-		GitInstallationID: uint(ga.InstallationID),
-		EnvironmentName:   env.Name,
-	})
-
-	if err != nil {
-		c.HandleAPIError(w, r, apierrors.NewErrInternal(err))
-		return
-	}
-
 	// delete all corresponding deployments
 	agent, err := c.GetAgent(r, cluster, "")
 
@@ -101,5 +87,29 @@ func (c *DeleteEnvironmentHandler) ServeHTTP(w http.ResponseWriter, r *http.Requ
 		return
 	}
 
+	err = actions.DeleteEnv(&actions.EnvOpts{
+		Client:            client,
+		ServerURL:         c.Config().ServerConf.ServerURL,
+		GitRepoOwner:      env.GitRepoOwner,
+		GitRepoName:       env.GitRepoName,
+		ProjectID:         project.ID,
+		ClusterID:         cluster.ID,
+		GitInstallationID: uint(ga.InstallationID),
+		EnvironmentName:   env.Name,
+	})
+
+	if err != nil {
+		if errors.Is(err, actions.ErrProtectedBranch) {
+			c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(
+				fmt.Errorf("We were unable to delete the Porter Preview Environment workflow files for this "+
+					"repository as the default branch is protected. Please manually delete them."), http.StatusConflict,
+			))
+			return
+		}
+
+		c.HandleAPIError(w, r, apierrors.NewErrInternal(err))
+		return
+	}
+
 	c.WriteResult(w, r, env.ToEnvironmentType())
 }

internal/integrations/ci/actions/actions.go

@@ -119,7 +119,7 @@ func (g *GithubActions) Setup() ([]byte, error) {
 		isOAuth := g.GithubOAuthIntegration != nil
 
 		if githubBranch.GetProtected() {
-			err = createBranchIfNotExists(client, g.GitRepoOwner, g.GitRepoName, branch, "porter-setup")
+			err = createNewBranch(client, g.GitRepoOwner, g.GitRepoName, branch, "porter-setup")
 
 			if err != nil {
 				return nil, fmt.Errorf(

internal/integrations/ci/actions/preview.go

@@ -88,7 +88,7 @@ func SetupEnv(opts *EnvOpts) error {
 	}
 
 	if githubBranch.GetProtected() {
-		err = createBranchIfNotExists(opts.Client, opts.GitRepoOwner, opts.GitRepoName, defaultBranch, "porter-preview")
+		err = createNewBranch(opts.Client, opts.GitRepoOwner, opts.GitRepoName, defaultBranch, "porter-preview")
 
 		if err != nil {
 			return fmt.Errorf(
@@ -163,7 +163,7 @@ func SetupEnv(opts *EnvOpts) error {
 	if err != nil {
 		if strings.Contains(err.Error(), "409 Could not create file") {
 			// possibly a write-protected branch
-			err = createBranchIfNotExists(opts.Client, opts.GitRepoOwner, opts.GitRepoName, defaultBranch, "porter-preview")
+			err = createNewBranch(opts.Client, opts.GitRepoOwner, opts.GitRepoName, defaultBranch, "porter-preview")
 
 			if err != nil {
 				return fmt.Errorf("write-protected branch %s. Error creating porter-preview branch: %w", defaultBranch, err)
@@ -268,6 +268,18 @@ func DeleteEnv(opts *EnvOpts) error {
 		}
 	}
 
+	githubBranch, _, err := opts.Client.Repositories.GetBranch(
+		context.Background(), opts.GitRepoOwner, opts.GitRepoName, defaultBranch, true,
+	)
+
+	if err != nil {
+		return err
+	}
+
+	if githubBranch.GetProtected() {
+		return ErrProtectedBranch
+	}
+
 	err = deleteGithubFile(
 		opts.Client,
 		fmt.Sprintf("porter_%s_env.yml", strings.ToLower(opts.EnvironmentName)),
@@ -381,39 +393,46 @@ func getPreviewDeleteActionYAML(opts *EnvOpts) ([]byte, error) {
 	return yaml.Marshal(actionYAML)
 }
 
-func createBranchIfNotExists(
+func createNewBranch(
 	client *github.Client,
 	gitRepoOwner, gitRepoName, baseBranch, headBranch string,
 ) error {
-	_, resp, err := client.Repositories.GetBranch(
+	_, _, err := client.Repositories.GetBranch(
 		context.Background(), gitRepoOwner, gitRepoName, headBranch, true,
 	)
 
-	if resp.StatusCode == http.StatusNotFound {
-		base, _, err := client.Repositories.GetBranch(
-			context.Background(), gitRepoOwner, gitRepoName, baseBranch, true,
-		)
-
-		if err != nil {
-			return err
-		}
+	headBranchRef := fmt.Sprintf("refs/heads/%s", headBranch)
 
-		_, _, err = client.Git.CreateRef(
-			context.Background(), gitRepoOwner, gitRepoName, &github.Reference{
-				Ref: github.String(fmt.Sprintf("refs/heads/%s", headBranch)),
-				Object: &github.GitObject{
-					SHA: base.Commit.SHA,
-				},
-			},
+	if err == nil {
+		// delete the stale branch
+		_, err := client.Git.DeleteRef(
+			context.Background(), gitRepoOwner, gitRepoName, headBranchRef,
 		)
 
 		if err != nil {
 			return err
 		}
+	} else {
+		return err
+	}
+
+	base, _, err := client.Repositories.GetBranch(
+		context.Background(), gitRepoOwner, gitRepoName, baseBranch, true,
+	)
 
-		return nil
+	if err != nil {
+		return err
 	}
 
+	_, _, err = client.Git.CreateRef(
+		context.Background(), gitRepoOwner, gitRepoName, &github.Reference{
+			Ref: github.String(headBranchRef),
+			Object: &github.GitObject{
+				SHA: base.Commit.SHA,
+			},
+		},
+	)
+
 	if err != nil {
 		return err
 	}