New Data Source: aws_vpc_peering_connections (#9491)

Output from acceptance testing:

```
--- PASS: TestAccDataSourceAwsVpcPeeringConnections_basic (14.21s)
```

aws/data_source_aws_vpc_peering_connections.go

@@ -0,0 +1,66 @@
+package aws
+
+import (
+	"fmt"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/service/ec2"
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
+	"github.com/terraform-providers/terraform-provider-aws/aws/internal/keyvaluetags"
+)
+
+func dataSourceAwsVpcPeeringConnections() *schema.Resource {
+	return &schema.Resource{
+		Read: dataSourceAwsVpcPeeringConnectionsRead,
+
+		Schema: map[string]*schema.Schema{
+			"filter": ec2CustomFiltersSchema(),
+			"tags":   tagsSchemaComputed(),
+			"ids": {
+				Type:     schema.TypeSet,
+				Computed: true,
+				Elem:     &schema.Schema{Type: schema.TypeString},
+				Set:      schema.HashString,
+			},
+		},
+	}
+}
+
+func dataSourceAwsVpcPeeringConnectionsRead(d *schema.ResourceData, meta interface{}) error {
+	conn := meta.(*AWSClient).ec2conn
+
+	req := &ec2.DescribeVpcPeeringConnectionsInput{}
+
+	req.Filters = append(req.Filters, buildEC2TagFilterList(
+		keyvaluetags.New(d.Get("tags").(map[string]interface{})).Ec2Tags(),
+	)...)
+	req.Filters = append(req.Filters, buildEC2CustomFilterList(
+		d.Get("filter").(*schema.Set),
+	)...)
+	if len(req.Filters) == 0 {
+		// Don't send an empty filters list; the EC2 API won't accept it.
+		req.Filters = nil
+	}
+
+	resp, err := conn.DescribeVpcPeeringConnections(req)
+	if err != nil {
+		return err
+	}
+	if resp == nil || len(resp.VpcPeeringConnections) == 0 {
+		return fmt.Errorf("no matching VPC peering connections found")
+	}
+
+	var ids []string
+	for _, pcx := range resp.VpcPeeringConnections {
+		ids = append(ids, aws.StringValue(pcx.VpcPeeringConnectionId))
+	}
+
+	d.SetId(resource.UniqueId())
+	err = d.Set("ids", ids)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

aws/data_source_aws_vpc_peering_connections_test.go

@@ -0,0 +1,80 @@
+package aws
+
+import (
+	"testing"
+
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
+)
+
+func TestAccDataSourceAwsVpcPeeringConnections_basic(t *testing.T) {
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:  func() { testAccPreCheck(t) },
+		Providers: testAccProviders,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccDataSourceAwsVpcPeeringConnectionsConfig,
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttr("data.aws_vpc_peering_connections.test_by_filters", "ids.#", "2"),
+				),
+			},
+		},
+	})
+}
+
+const testAccDataSourceAwsVpcPeeringConnectionsConfig = `
+resource "aws_vpc" "foo" {
+  cidr_block = "10.1.0.0/16"
+
+  tags = {
+    Name = "terraform-testacc-vpc-peering-connection-data-source-foo"
+    Type = "primary"
+  }
+}
+
+resource "aws_vpc" "bar" {
+  cidr_block = "10.2.0.0/16"
+
+  tags = {
+    Name = "terraform-testacc-vpc-peering-connection-data-source-bar"
+    Type = "secondary"
+  }
+}
+
+resource "aws_vpc" "baz" {
+  cidr_block = "10.3.0.0/16"
+
+  tags = {
+    Name = "terraform-testacc-vpc-peering-connection-data-source-baz"
+    Type = "secondary"
+  }
+}
+
+resource "aws_vpc_peering_connection" "conn1" {
+  vpc_id = aws_vpc.foo.id
+  peer_vpc_id = aws_vpc.bar.id
+  auto_accept = true
+
+  tags = {
+    Name = "terraform-testacc-vpc-peering-connection-data-source-foo-to-bar"
+    Environment = "test"
+  }
+}
+
+resource "aws_vpc_peering_connection" "conn2" {
+  vpc_id = aws_vpc.foo.id
+  peer_vpc_id = aws_vpc.baz.id
+  auto_accept = true
+
+  tags = {
+    Name = "terraform-testacc-vpc-peering-connection-data-source-foo-to-baz"
+    Environment = "test"
+  }
+}
+
+data "aws_vpc_peering_connections" "test_by_filters" {
+  filter {
+    name   = "vpc-peering-connection-id"
+    values = [aws_vpc_peering_connection.conn1.id, aws_vpc_peering_connection.conn2.id]
+  }
+}
+`

aws/provider.go

@@ -342,6 +342,7 @@ func Provider() *schema.Provider {
 			"aws_vpc_endpoint":                               dataSourceAwsVpcEndpoint(),
 			"aws_vpc_endpoint_service":                       dataSourceAwsVpcEndpointService(),
 			"aws_vpc_peering_connection":                     dataSourceAwsVpcPeeringConnection(),
+			"aws_vpc_peering_connections":                    dataSourceAwsVpcPeeringConnections(),
 			"aws_vpn_gateway":                                dataSourceAwsVpnGateway(),
 			"aws_waf_ipset":                                  dataSourceAwsWafIpSet(),
 			"aws_waf_rule":                                   dataSourceAwsWafRule(),
@@ -357,7 +358,6 @@ func Provider() *schema.Provider {
 			"aws_wafv2_web_acl":                              dataSourceAwsWafv2WebACL(),
 			"aws_workspaces_bundle":                          dataSourceAwsWorkspacesBundle(),
 			"aws_workspaces_directory":                       dataSourceAwsWorkspacesDirectory(),
-
 			// Adding the Aliases for the ALB -> LB Rename
 			"aws_lb":               dataSourceAwsLb(),
 			"aws_alb":              dataSourceAwsLb(),

website/docs/d/vpc_peering_connections.html.markdown

@@ -0,0 +1,57 @@
+---
+subcategory: "VPC"
+layout: "aws"
+page_title: "AWS: aws_vpc_peering_connections"
+description: |-
+    Lists peering connections
+---
+
+# Data Source: aws_vpc_peering_connections
+
+Use this data source to get IDs of Amazon VPC peering connections
+To get more details on each connection, use the data resource [aws_vpc_peering_connection](/docs/providers/aws/d/vpc_peering_connection.html)
+
+Note: To use this data source in a count, the resources should exist before trying to access
+the data source, as noted in [issue 4149](https://github.com/hashicorp/terraform/issues/4149)
+
+## Example Usage
+
+```hcl
+# Declare the data source
+data "aws_vpc_peering_connections" "pcs" {
+  filter {
+    name   = "requester-vpc-info.vpc-id"
+    values = [aws_vpc.foo.id]
+  }
+}
+
+# get the details of each resource
+data "aws_vpc_peering_connection" "pc" {
+  count = length(data.aws_vpc_peering_connections.pcs.ids)
+  id    = data.aws_vpc_peering_connections.pcs.ids[count.index]
+}
+```
+
+## Argument Reference
+
+The arguments of this data source act as filters for querying the available VPC peering connections.
+
+* `filter` - (Optional) Custom filter block as described below.
+
+* `tags` - (Optional) A mapping of tags, each pair of which must exactly match
+  a pair on the desired VPC Peering Connection.
+
+More complex filters can be expressed using one or more `filter` sub-blocks,
+which take the following arguments:
+
+* `name` - (Required) The name of the field to filter by, as defined by
+  [the underlying AWS API](http://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_DescribeVpcPeeringConnections.html).
+
+* `values` - (Required) Set of values that are accepted for the given field.
+  A VPC Peering Connection will be selected if any one of the given values matches.
+
+## Attributes Reference
+
+All of the argument attributes except `filter` are also exported as result attributes.
+
+* `ids` - The IDs of the VPC Peering Connections.