Allow default branch to be set to master/main on update, using a new github_branch_default resource

github/provider.go

@@ -66,6 +66,7 @@ func Provider() terraform.ResourceProvider {
 			"github_user_gpg_key":                resourceGithubUserGpgKey(),
 			"github_user_invitation_accepter":    resourceGithubUserInvitationAccepter(),
 			"github_user_ssh_key":                resourceGithubUserSshKey(),
+			"github_branch_default":              resourceGithubBranchDefault(),
 		},
 
 		DataSourcesMap: map[string]*schema.Resource{

github/resource_github_branch_default.go

@@ -0,0 +1,126 @@
+package github
+
+import (
+	"context"
+	"log"
+
+	"github.com/hashicorp/terraform-plugin-sdk/helper/schema"
+)
+
+func resourceGithubBranchDefault() *schema.Resource {
+	return &schema.Resource{
+		Create: resourceGithubBranchDefaultCreate,
+		Read:   resourceGithubBranchDefaultRead,
+		Delete: resourceGithubBranchDefaultDelete,
+		Update: resourceGithubBranchDefaultUpdate,
+		Importer: &schema.ResourceImporter{
+			State: schema.ImportStatePassthrough,
+		},
+
+		Schema: map[string]*schema.Schema{
+			"branch": {
+				Type:     schema.TypeString,
+				Required: true,
+			},
+			"repository": {
+				Type:     schema.TypeString,
+				Required: true,
+				ForceNew: true,
+			},
+		},
+	}
+}
+
+func resourceGithubBranchDefaultCreate(d *schema.ResourceData, meta interface{}) error {
+
+	client := meta.(*Owner).v3client
+	owner := meta.(*Owner).name
+	repoName := d.Get("repository").(string)
+	defaultBranch := d.Get("branch").(string)
+
+	ctx := context.Background()
+
+	repository, _, err := client.Repositories.Get(ctx, owner, repoName)
+	if err != nil {
+		return err
+	}
+
+	repository.DefaultBranch = &defaultBranch
+
+	log.Printf("[DEBUG] Creating branch default: %s (%s/%s)", defaultBranch, owner, repoName)
+	if _, _, err := client.Repositories.Edit(ctx, owner, repoName, repository); err != nil {
+		return err
+	}
+
+	d.SetId(repoName)
+
+	return resourceGithubBranchDefaultRead(d, meta)
+}
+
+func resourceGithubBranchDefaultRead(d *schema.ResourceData, meta interface{}) error {
+
+	client := meta.(*Owner).v3client
+	owner := meta.(*Owner).name
+	repoName := d.Id()
+
+	ctx := context.WithValue(context.Background(), ctxId, d.Id())
+
+	repository, _, err := client.Repositories.Get(ctx, owner, repoName)
+	if err != nil {
+		return err
+	}
+
+	if repository.DefaultBranch == nil {
+		d.SetId("")
+		return nil
+	}
+
+	d.Set("branch", *repository.DefaultBranch)
+	d.Set("repository", *repository.Name)
+	return nil
+}
+
+func resourceGithubBranchDefaultDelete(d *schema.ResourceData, meta interface{}) error {
+
+	client := meta.(*Owner).v3client
+	owner := meta.(*Owner).name
+	repoName := d.Id()
+	defaultBranch := d.Get("branch").(string)
+
+	ctx := context.Background()
+
+	repository, _, err := client.Repositories.Get(ctx, owner, repoName)
+	if err != nil {
+		return err
+	}
+
+	repository.DefaultBranch = nil
+
+	log.Printf("[DEBUG] Removing branch default: %s (%s/%s)", defaultBranch, owner, repoName)
+	_, _, err = client.Repositories.Edit(ctx, owner, repoName, repository)
+	return err
+}
+
+func resourceGithubBranchDefaultUpdate(d *schema.ResourceData, meta interface{}) error {
+
+	client := meta.(*Owner).v3client
+	owner := meta.(*Owner).name
+	repoName := d.Id()
+	defaultBranch := d.Get("branch").(string)
+
+	ctx := context.Background()
+
+	repository, _, err := client.Repositories.Get(ctx, owner, repoName)
+	if err != nil {
+		return err
+	}
+
+	repository.DefaultBranch = &defaultBranch
+
+	log.Printf("[DEBUG] Updating branch default: %s (%s/%s)", defaultBranch, owner, repoName)
+	if _, _, err := client.Repositories.Edit(ctx, owner, repoName, repository); err != nil {
+		return err
+	}
+
+	return resourceGithubBranchDefaultRead(d, meta)
+}

github/resource_github_branch_default_test.go

@@ -0,0 +1,121 @@
+package github
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/hashicorp/terraform-plugin-sdk/helper/acctest"
+	"github.com/hashicorp/terraform-plugin-sdk/helper/resource"
+)
+
+func TestAccGithubBranchDefault(t *testing.T) {
+
+	randomID := acctest.RandStringFromCharSet(5, acctest.CharSetAlphaNum)
+
+	t.Run("creates and manages branch defaults", func(t *testing.T) {
+
+		config := fmt.Sprintf(`
+
+			resource "github_repository" "test" {
+				name      = "tf-acc-test-%s"
+				auto_init = true
+			}
+
+			resource "github_branch_default" "test" {
+				repository     = github_repository.test.name
+				branch         = "main"
+			}
+		`, randomID)
+
+		check := resource.ComposeTestCheckFunc(
+			resource.TestCheckResourceAttr(
+				"github_branch_default.test", "branch",
+				"main",
+			),
+			resource.TestCheckResourceAttr(
+				"github_branch_default.test", "repository",
+				fmt.Sprintf("tf-acc-test-%s", randomID),
+			),
+		)
+
+		testCase := func(t *testing.T, mode string) {
+			resource.Test(t, resource.TestCase{
+				PreCheck:  func() { skipUnlessMode(t, mode) },
+				Providers: testAccProviders,
+				Steps: []resource.TestStep{
+					{
+						Config: config,
+						Check:  check,
+					},
+				},
+			})
+		}
+
+		t.Run("with an anonymous account", func(t *testing.T) {
+			t.Skip("anonymous account not supported for this operation")
+		})
+
+		t.Run("with an individual account", func(t *testing.T) {
+			testCase(t, individual)
+		})
+
+		t.Run("with an organization account", func(t *testing.T) {
+			testCase(t, organization)
+		})
+
+	})
+
+	t.Run("can be configured to override the default_branch of the repository", func(t *testing.T) {
+
+		config := fmt.Sprintf(`
+			resource "github_repository" "test" {
+				name      = "tf-acc-test-%s"
+				default_branch = "main"
+				auto_init = true
+			}
+
+			resource "github_branch_default" "test" {
+				repository     = github_repository.test.name
+				branch         = "override"
+			}
+
+		`, randomID)
+
+		check := resource.ComposeTestCheckFunc(
+			resource.TestCheckResourceAttr(
+				"github_branch_default.test", "branch",
+				"override",
+			),
+			resource.TestCheckResourceAttr(
+				"github_branch_default.test", "repository",
+				fmt.Sprintf("tf-acc-test-%s", randomID),
+			),
+		)
+
+		testCase := func(t *testing.T, mode string) {
+			resource.Test(t, resource.TestCase{
+				PreCheck:  func() { skipUnlessMode(t, mode) },
+				Providers: testAccProviders,
+				Steps: []resource.TestStep{
+					{
+						Config: config,
+						Check:  check,
+					},
+				},
+			})
+		}
+
+		t.Run("with an anonymous account", func(t *testing.T) {
+			t.Skip("anonymous account not supported for this operation")
+		})
+
+		t.Run("with an individual account", func(t *testing.T) {
+			testCase(t, individual)
+		})
+
+		t.Run("with an organization account", func(t *testing.T) {
+			testCase(t, organization)
+		})
+
+	})
+}

github/resource_github_repository.go

@@ -102,6 +102,7 @@ func resourceGithubRepository() *schema.Resource {
 				Optional:    true,
 				Computed:    true,
 				Description: "Can only be set after initial repository creation, and only if the target branch exists",
+				Deprecated:  "Use the github_branch_default resource instead",
 			},
 			"license_template": {
 				Type:     schema.TypeString,

website/docs/r/branch_default.html.markdown

@@ -0,0 +1,53 @@
+---
+layout: "github"
+page_title: "GitHub: github_branch_default"
+description: |-
+  Provides a GitHub branch default for a given repository.
+---
+
+# github_branch_default
+
+Provides a GitHub branch default resource.
+
+This resource allows you to set the default branch for a given repository. 
+
+## Example Usage
+
+```hcl
+resource "github_repository" "example" {
+  name        = "example"
+  description = "My awesome codebase"
+
+  private = true
+
+  template {
+    owner = "github"
+    repository = "terraform-module-template"
+  }
+}
+
+resource "github_branch" "development" {
+  repository = github_repository.example.name
+  branch     = "development"
+}
+
+resource "github_branch_default" "default"{
+  repository = github_repository.example.name
+  branch     = github_branch.development.branch
+}
+```
+
+## Argument Reference
+
+The following arguments are supported:
+
+* `repository` - (Required) The GitHub repository
+* `branch` - (Required) The branch (e.g. `main`)
+
+## Import
+
+GitHub Branch Defaults can be imported using an ID made up of `repository`, e.g.
+
+```
+$ terraform import github_branch_default.branch_default my-repo
+```

website/docs/r/repository.html.markdown

@@ -67,7 +67,7 @@ The following arguments are supported:
 
 * `license_template` - (Optional) Use the [name of the template](https://github.com/github/choosealicense.com/tree/gh-pages/_licenses) without the extension. For example, "mit" or "mpl-2.0".
 
-* `default_branch` - (Optional) The name of the default branch of the repository. **NOTE:** This can only be set after a repository has already been created,
+* `default_branch` - (Optional) (Deprecated: Use `github_branch_default` resource instead) The name of the default branch of the repository. **NOTE:** This can only be set after a repository has already been created,
 and after a correct reference has been created for the target branch inside the repository. This means a user will have to omit this parameter from the
 initial repository creation and create the target branch inside of the repository prior to setting this attribute.