Add members attribute to iam_group data source

aws/data_source_aws_iam_group.go

@@ -30,6 +30,30 @@ func dataSourceAwsIAMGroup() *schema.Resource {
 				Type:     schema.TypeString,
 				Required: true,
 			},
+			"users": {
+				Type:     schema.TypeList,
+				Computed: true,
+				Elem: &schema.Resource{
+					Schema: map[string]*schema.Schema{
+						"arn": {
+							Type:     schema.TypeString,
+							Computed: true,
+						},
+						"user_id": {
+							Type:     schema.TypeString,
+							Computed: true,
+						},
+						"user_name": {
+							Type:     schema.TypeString,
+							Computed: true,
+						},
+						"path": {
+							Type:     schema.TypeString,
+							Computed: true,
+						},
+					},
+				},
+			},
 		},
 	}
 }
@@ -58,6 +82,22 @@ func dataSourceAwsIAMGroupRead(d *schema.ResourceData, meta interface{}) error {
 	d.Set("arn", group.Arn)
 	d.Set("path", group.Path)
 	d.Set("group_id", group.GroupId)
+	if err := d.Set("users", dataSourceUsersRead(resp.Users)); err != nil {
+		return fmt.Errorf("error setting users: %s", err)
+	}
 
 	return nil
 }
+
+func dataSourceUsersRead(iamUsers []*iam.User) []map[string]interface{} {
+	users := make([]map[string]interface{}, 0, len(iamUsers))
+	for _, i := range iamUsers {
+		u := make(map[string]interface{})
+		u["arn"] = aws.StringValue(i.Arn)
+		u["user_id"] = aws.StringValue(i.UserId)
+		u["user_name"] = aws.StringValue(i.UserName)
+		u["path"] = aws.StringValue(i.Path)
+		users = append(users, u)
+	}
+	return users
+}

aws/data_source_aws_iam_group_test.go

@@ -2,7 +2,6 @@ package aws
 
 import (
 	"fmt"
-	"regexp"
 	"testing"
 
 	"github.com/hashicorp/terraform-plugin-sdk/helper/acctest"
@@ -22,7 +21,34 @@ func TestAccAWSDataSourceIAMGroup_basic(t *testing.T) {
 					resource.TestCheckResourceAttrSet("data.aws_iam_group.test", "group_id"),
 					resource.TestCheckResourceAttr("data.aws_iam_group.test", "path", "/"),
 					resource.TestCheckResourceAttr("data.aws_iam_group.test", "group_name", groupName),
-					resource.TestMatchResourceAttr("data.aws_iam_group.test", "arn", regexp.MustCompile("^arn:aws:iam::[0-9]{12}:group/"+groupName)),
+					testAccCheckResourceAttrGlobalARN("data.aws_iam_group.test", "arn", "iam", fmt.Sprintf("group/%s", groupName)),
+				),
+			},
+		},
+	})
+}
+
+func TestAccAWSDataSourceIAMGroup_users(t *testing.T) {
+	groupName := fmt.Sprintf("test-datasource-group-%d", acctest.RandInt())
+	userName := fmt.Sprintf("test-datasource-user-%d", acctest.RandInt())
+	groupMemberShipName := fmt.Sprintf("test-datasource-group-membership-%d", acctest.RandInt())
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:  func() { testAccPreCheck(t) },
+		Providers: testAccProviders,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccAwsIAMGroupConfigWithUser(groupName, userName, groupMemberShipName),
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttrSet("data.aws_iam_group.test", "group_id"),
+					resource.TestCheckResourceAttr("data.aws_iam_group.test", "path", "/"),
+					resource.TestCheckResourceAttr("data.aws_iam_group.test", "group_name", groupName),
+					testAccCheckResourceAttrGlobalARN("data.aws_iam_group.test", "arn", "iam", fmt.Sprintf("group/%s", groupName)),
+					resource.TestCheckResourceAttr("data.aws_iam_group.test", "users.#", "1"),
+					resource.TestCheckResourceAttrPair("data.aws_iam_group.test", "users.0.arn", "aws_iam_user.user", "arn"),
+					resource.TestCheckResourceAttrPair("data.aws_iam_group.test", "users.0.user_id", "aws_iam_user.user", "unique_id"),
+					resource.TestCheckResourceAttrPair("data.aws_iam_group.test", "users.0.user_name", "aws_iam_user.user", "name"),
+					resource.TestCheckResourceAttrPair("data.aws_iam_group.test", "users.0.path", "aws_iam_user.user", "path"),
 				),
 			},
 		},
@@ -41,3 +67,26 @@ data "aws_iam_group" "test" {
 }
 `, name)
 }
+
+func testAccAwsIAMGroupConfigWithUser(groupName, userName, membershipName string) string {
+	return fmt.Sprintf(`
+resource "aws_iam_group" "group" {
+	name = "%s"
+	path = "/"
+}
+
+resource "aws_iam_user" "user" {
+	name = "%s"
+}
+
+resource "aws_iam_group_membership" "team" {
+	name = "%s"
+	users = ["${aws_iam_user.user.name}"]
+	group = "${aws_iam_group.group.name}"
+}
+
+data "aws_iam_group" "test" {
+	group_name = "${aws_iam_group_membership.team.group}"	
+}
+`, groupName, userName, membershipName)
+}

website/docs/d/iam_group.html.markdown

@@ -31,3 +31,15 @@ data "aws_iam_group" "example" {
 * `path` - The path to the group.
 
 * `group_id` - The stable and unique string identifying the group.
+
+* `users` - List of objects containing group member information. See supported fields below.
+
+### `users`
+
+* `arn` - The Amazon Resource Name (ARN) specifying the iam user.
+
+* `user_id` - The stable and unique string identifying the iam user.
+
+* `user_name` - The name of the iam user.
+
+* `path` - The path to the iam user.