d/Adds a url_suffix attribute to data_source_aws_partition

aws/config.go

@@ -196,6 +196,7 @@ type AWSClient struct {
 	redshiftconn          *redshift.Redshift
 	r53conn               *route53.Route53
 	partition             string
+	dnsSuffix             string
 	accountid             string
 	supportedplatforms    []string
 	region                string
@@ -458,6 +459,20 @@ func (c *Config) Client() (interface{}, error) {
 		}
 	}
 
+	// Infer URL Suffix from STS Endpoint
+	resolver := endpoints.DefaultResolver()
+	endpoint, err := resolver.EndpointFor(endpoints.StatesServiceID, client.region)
+	if err != nil {
+		return nil, fmt.Errorf("Failed to resolve endpoint. Errors: %s", err)
+	}
+
+	dnsSuffix, err := parseDNSSuffixFromEndpoint(endpoint.URL, client.region)
+	if err != nil {
+		return nil, fmt.Errorf("Failed to resolve URL Suffix. Errors: %s", err)
+	}
+
+	client.dnsSuffix = aws.StringValue(dnsSuffix)
+
 	client.ec2conn = ec2.New(awsEc2Sess)
 
 	if !c.SkipGetEC2Platforms {
@@ -610,6 +625,24 @@ func (c *Config) Client() (interface{}, error) {
 	return &client, nil
 }
 
+func parseDNSSuffixFromEndpoint(endpoint string, region string) (*string, error) {
+	e := strings.Split(endpoint, ".")
+
+	// Expect endpoints with at least three elements
+	// {service}.{optional region}.{one or more zones}.{root}
+	if len(e) < 2 {
+		return nil, fmt.Errorf("Could not determine URL Suffix from endpoint '%s'", endpoint)
+	}
+
+	// An endpoint may have the region in the second element
+	if e[1] == region {
+		return aws.String(strings.Join(e[2:], ".")), nil
+	}
+
+	// Without a region, the URL Suffix is everything past the first element
+	return aws.String(strings.Join(e[1:], ".")), nil
+}
+
 func hasEc2Classic(platforms []string) bool {
 	for _, p := range platforms {
 		if p == "EC2" {

aws/data_source_aws_partition.go

@@ -16,6 +16,10 @@ func dataSourceAwsPartition() *schema.Resource {
 				Type:     schema.TypeString,
 				Computed: true,
 			},
+			"dns_suffix": {
+				Type:     schema.TypeString,
+				Computed: true,
+			},
 		},
 	}
 }
@@ -29,5 +33,8 @@ func dataSourceAwsPartitionRead(d *schema.ResourceData, meta interface{}) error
 	log.Printf("[DEBUG] Setting AWS Partition to %s.", client.partition)
 	d.Set("partition", meta.(*AWSClient).partition)
 
+	log.Printf("[DEBUG] Setting AWS URL Suffix to %s.", client.dnsSuffix)
+	d.Set("dns_suffix", meta.(*AWSClient).dnsSuffix)
+
 	return nil
 }

aws/data_source_aws_partition_test.go

@@ -17,6 +17,7 @@ func TestAccAWSPartition_basic(t *testing.T) {
 				Config: testAccCheckAwsPartitionConfig_basic,
 				Check: resource.ComposeTestCheckFunc(
 					testAccCheckAwsPartition("data.aws_partition.current"),
+					testAccCheckAwsDnsSuffix("data.aws_partition.current"),
 				),
 			},
 		},
@@ -39,6 +40,26 @@ func testAccCheckAwsPartition(n string) resource.TestCheckFunc {
 	}
 }
 
+func testAccCheckAwsDnsSuffix(n string) resource.TestCheckFunc {
+	return func(s *terraform.State) error {
+		rs, ok := s.RootModule().Resources[n]
+		if !ok {
+			return fmt.Errorf("Can't find resource: %s", n)
+		}
+
+		expected := testAccProvider.Meta().(*AWSClient).dnsSuffix
+		if rs.Primary.Attributes["dns_suffix"] != expected {
+			return fmt.Errorf("Incorrect DNS Suffix: expected %q, got %q", expected, rs.Primary.Attributes["dns_suffix"])
+		}
+
+		if rs.Primary.Attributes["dns_suffix"] == "" {
+			return fmt.Errorf("DNS Suffix expected to not be nil")
+		}
+
+		return nil
+	}
+}
+
 const testAccCheckAwsPartitionConfig_basic = `
 data "aws_partition" "current" { }
 `

website/docs/d/partition.html.markdown

@@ -8,7 +8,8 @@ description: |-
 
 # Data Source: aws_partition
 
-Use this data source to lookup current AWS partition in which Terraform is working
+Use this data source to lookup information about the current AWS partition in
+which Terraform is working.
 
 ## Example Usage
 
@@ -36,4 +37,5 @@ There are no arguments available for this data source.
 
 ## Attributes Reference
 
-`partition` is set to the identifier of the current partition.
+* `partition` is set to the identifier of the current partition.
+* `dns_suffix` is set to the base DNS domain name for the current partition (e.g. `amazonaws.com` in AWS Commercial, `amazonaws.com.cn` in AWS China).