New Data Source: aws_sfn_activity (#11080)

Output from acceptance testing:

```
--- PASS: TestAccAWSStepFunctionsActivityDataSource (13.22s)
```

aws/data_source_aws_sfn_activity.go

@@ -0,0 +1,108 @@
+package aws
+
+import (
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/service/sfn"
+	"github.com/hashicorp/terraform-plugin-sdk/helper/schema"
+)
+
+func dataSourceAwsSfnActivity() *schema.Resource {
+	return &schema.Resource{
+		Read: dataSourceAwsSfnActivityRead,
+
+		Schema: map[string]*schema.Schema{
+			"name": {
+				Type:     schema.TypeString,
+				Computed: true,
+				Optional: true,
+				ExactlyOneOf: []string{
+					"arn",
+					"name",
+				},
+			},
+			"arn": {
+				Type:     schema.TypeString,
+				Computed: true,
+				Optional: true,
+				ExactlyOneOf: []string{
+					"arn",
+					"name",
+				},
+			},
+			"creation_date": {
+				Type:     schema.TypeString,
+				Computed: true,
+			},
+		},
+	}
+}
+
+func dataSourceAwsSfnActivityRead(d *schema.ResourceData, meta interface{}) error {
+	client := meta.(*AWSClient)
+	conn := client.sfnconn
+	log.Print("[DEBUG] Reading Step Function Activity")
+
+	if nm, ok := d.GetOk("name"); ok {
+		name := nm.(string)
+		var acts []*sfn.ActivityListItem
+
+		err := conn.ListActivitiesPages(&sfn.ListActivitiesInput{}, func(page *sfn.ListActivitiesOutput, b bool) bool {
+			for _, a := range page.Activities {
+				if name == aws.StringValue(a.Name) {
+					acts = append(acts, a)
+				}
+			}
+			return true
+		})
+
+		if err != nil {
+			return fmt.Errorf("Error listing activities: %s", err)
+		}
+
+		if len(acts) == 0 {
+			return fmt.Errorf("No activity found with name %s in this region", name)
+		}
+
+		if len(acts) > 1 {
+			return fmt.Errorf("Found more than 1 activity with name %s in this region", name)
+		}
+
+		act := acts[0]
+
+		d.SetId(*act.ActivityArn)
+		d.Set("name", act.Name)
+		d.Set("arn", act.ActivityArn)
+		if err := d.Set("creation_date", act.CreationDate.Format(time.RFC3339)); err != nil {
+			log.Printf("[DEBUG] Error setting creation_date: %s", err)
+		}
+	}
+
+	if rnm, ok := d.GetOk("arn"); ok {
+		arn := rnm.(string)
+		params := &sfn.DescribeActivityInput{
+			ActivityArn: aws.String(arn),
+		}
+
+		act, err := conn.DescribeActivity(params)
+		if err != nil {
+			return fmt.Errorf("Error describing activities: %s", err)
+		}
+
+		if act == nil {
+			return fmt.Errorf("No activity found with arn %s in this region", arn)
+		}
+
+		d.SetId(*act.ActivityArn)
+		d.Set("name", act.Name)
+		d.Set("arn", act.ActivityArn)
+		if err := d.Set("creation_date", act.CreationDate.Format(time.RFC3339)); err != nil {
+			log.Printf("[DEBUG] Error setting creation_date: %s", err)
+		}
+	}
+
+	return nil
+}

aws/data_source_aws_sfn_activity_test.go

@@ -0,0 +1,60 @@
+package aws
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/hashicorp/terraform-plugin-sdk/helper/acctest"
+	"github.com/hashicorp/terraform-plugin-sdk/helper/resource"
+)
+
+func TestAccAWSStepFunctionsActivityDataSource(t *testing.T) {
+	rName := acctest.RandomWithPrefix("tf-acc-test")
+	resourceName := "aws_sfn_activity.test"
+	dataName := "data.aws_sfn_activity.test"
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:  func() { testAccPreCheck(t) },
+		Providers: testAccProviders,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccCheckAWSStepFunctionsActivityDataSourceConfig_ActivityArn(rName),
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttrPair(resourceName, "id", dataName, "id"),
+					resource.TestCheckResourceAttrPair(resourceName, "creation_date", dataName, "creation_date"),
+					resource.TestCheckResourceAttrPair(resourceName, "name", dataName, "name"),
+				),
+			},
+			{
+				Config: testAccCheckAWSStepFunctionsActivityDataSourceConfig_ActivityName(rName),
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttrPair(resourceName, "id", dataName, "id"),
+					resource.TestCheckResourceAttrPair(resourceName, "creation_date", dataName, "creation_date"),
+					resource.TestCheckResourceAttrPair(resourceName, "name", dataName, "name"),
+				),
+			},
+		},
+	})
+}
+
+func testAccCheckAWSStepFunctionsActivityDataSourceConfig_ActivityArn(rName string) string {
+	return fmt.Sprintf(`
+resource aws_sfn_activity "test" {
+  name = "%s"
+}
+data aws_sfn_activity "test" {
+  arn = "${aws_sfn_activity.test.id}"
+}
+`, rName)
+}
+
+func testAccCheckAWSStepFunctionsActivityDataSourceConfig_ActivityName(rName string) string {
+	return fmt.Sprintf(`
+resource aws_sfn_activity "test" {
+  name = "%s"
+}
+data aws_sfn_activity "test" {
+  name = "${aws_sfn_activity.test.name}"
+}
+`, rName)
+}

aws/provider.go

@@ -281,6 +281,7 @@ func Provider() terraform.ResourceProvider {
 			"aws_secretsmanager_secret_version":             dataSourceAwsSecretsManagerSecretVersion(),
 			"aws_servicequotas_service":                     dataSourceAwsServiceQuotasService(),
 			"aws_servicequotas_service_quota":               dataSourceAwsServiceQuotasServiceQuota(),
+			"aws_sfn_activity":                              dataSourceAwsSfnActivity(),
 			"aws_sfn_state_machine":                         dataSourceAwsSfnStateMachine(),
 			"aws_sns_topic":                                 dataSourceAwsSnsTopic(),
 			"aws_sqs_queue":                                 dataSourceAwsSqsQueue(),

website/aws.erb

@@ -2986,6 +2986,9 @@
                         <li>
                             <a href="#">Data Sources</a>
                             <ul class="nav nav-auto-expand">
+                                <li>
+                                    <a href="/docs/providers/aws/d/sfn_activity.html">aws_sfn_activity</a>
+                                </li>
                                 <li>
                                     <a href="/docs/providers/aws/d/sfn_state_machine.html">aws_sfn_state_machine</a>
                                 </li>

website/docs/d/sfn_activity.html.markdown

@@ -0,0 +1,33 @@
+---
+subcategory: "Step Function (SFN)"
+layout: "aws"
+page_title: "AWS: aws_sfn_activity"
+description: |-
+  Use this data source to get information about a Step Functions Activity.
+---
+
+# Data Source: aws_sfn_activity
+
+Provides a Step Functions Activity data source
+
+## Example Usage
+
+```hcl
+data "aws_sfn_activity" "sfn_activity" {
+  name = "my-activity"
+}
+```
+
+## Argument Reference
+
+The following arguments are supported:
+
+* `name` - (Optional) The name that identifies the activity.
+* `arn` - (Optional) The Amazon Resource Name (ARN) that identifies the activity.
+
+## Attributes Reference
+
+In addition to all arguments above, the following attributes are exported:
+
+* `id` - The Amazon Resource Name (ARN) that identifies the activity.
+* `creation_date` - The date the activity was created.