Resell V2 API - add subnets Create method

Add Create method for the Subnets package.
Add tests and doc example.

selvpcclient/resell/v2/subnets/doc.go

@@ -19,5 +19,25 @@ Example of getting all subnets
   for _, subnet := range allSubnet {
     fmt.Println(subnet)
   }
+
+Example of creating subnets
+
+  createOpts := subnets.SubnetOpts{
+    Subnets: []subnets.SubnetOpt{
+      {
+        Region:       "ru-3",
+        Type:         selvpcclient.IPv4,
+        PrefixLength: 29,
+        Quantity:     1,
+      },
+    },
+	}
+  newSubnets, _, err := subnets.Create(ctx, resellClient, projectID, createOpts)
+  if err != nil {
+  	log.Fatal(err)
+  }
+  for _, newSubnet := range newSubnets {
+  	fmt.Printf("%v\n", newSubnet)
+  }
 */
 package subnets

selvpcclient/resell/v2/subnets/request_opts.go

@@ -0,0 +1,24 @@
+package subnets
+
+import "github.com/selectel/go-selvpcclient/selvpcclient"
+
+// SubnetOpts represents options for the subnets Create request.
+type SubnetOpts struct {
+	// Subnets represents options for all subnets.
+	Subnets []SubnetOpt `json:"subnets"`
+}
+
+// SubnetOpt represents options for the single subnet.
+type SubnetOpt struct {
+	// Region represents a region of where the subnet should reside.
+	Region string `json:"region"`
+
+	// Quantity represents how many subnets do we need to create.
+	Quantity int `json:"quantity"`
+
+	// Type represents ip version type.
+	Type selvpcclient.IPVersion `json:"type"`
+
+	// PrefixLength represents length of the subnet prefix.
+	PrefixLength int `json:"prefix_length"`
+}

selvpcclient/resell/v2/subnets/requests.go

@@ -1,7 +1,9 @@
 package subnets
 
 import (
+	"bytes"
 	"context"
+	"encoding/json"
 	"strings"
 
 	"github.com/selectel/go-selvpcclient/selvpcclient"
@@ -54,3 +56,32 @@ func List(ctx context.Context, client *selvpcclient.ServiceClient) ([]*Subnet, *
 
 	return result.Subnets, responseResult, nil
 }
+
+// Create requests a creation of the subnets in the specified project.
+func Create(ctx context.Context, client *selvpcclient.ServiceClient, projectID string, createOpts SubnetOpts) ([]*Subnet, *selvpcclient.ResponseResult, error) {
+	createSubnetsOpts := &createOpts
+	requestBody, err := json.Marshal(createSubnetsOpts)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	url := strings.Join([]string{client.Endpoint, resourceURL, "projects", projectID}, "/")
+	responseResult, err := client.DoRequest(ctx, "POST", url, bytes.NewReader(requestBody))
+	if err != nil {
+		return nil, nil, err
+	}
+	if responseResult.Err != nil {
+		return nil, responseResult, responseResult.Err
+	}
+
+	// Extract subnets from the response body.
+	var result struct {
+		Subnets []*Subnet `json:"subnets"`
+	}
+	err = responseResult.ExtractResult(&result)
+	if err != nil {
+		return nil, responseResult, err
+	}
+
+	return result.Subnets, responseResult, nil
+}

selvpcclient/resell/v2/subnets/testing/fixtures.go

@@ -3,6 +3,7 @@ package testing
 import (
 	"time"
 
+	"github.com/selectel/go-selvpcclient/selvpcclient"
 	"github.com/selectel/go-selvpcclient/selvpcclient/resell/v2/servers"
 	"github.com/selectel/go-selvpcclient/selvpcclient/resell/v2/subnets"
 )
@@ -98,3 +99,81 @@ var TestListSubnetsSingleResponse = []*subnets.Subnet{
 		Status:    "ACTIVE",
 	},
 }
+
+// TestCreateSubnetsOptsRaw represents marshalled options for the Create request.
+const TestCreateSubnetsOptsRaw = `
+{
+    "subnets": [
+        {
+            "region": "ru-2",
+            "type": "ipv4",
+            "quantity": 1,
+            "prefix_length": 29
+        },
+        {
+            "region": "ru-1",
+            "type": "ipv4",
+            "quantity": 1,
+            "prefix_length": 29
+        }
+    ]
+}
+`
+
+// TestCreateSubnetsOpts represent options for the Create request.
+var TestCreateSubnetsOpts = subnets.SubnetOpts{
+	Subnets: []subnets.SubnetOpt{
+		{
+			Type:         selvpcclient.IPv4,
+			PrefixLength: 29,
+			Region:       "ru-2",
+			Quantity:     1,
+		},
+		{
+			Type:         selvpcclient.IPv4,
+			PrefixLength: 29,
+			Region:       "ru-1",
+			Quantity:     1,
+		},
+	},
+}
+
+// TestCreateSubnetsResponseRaw represents a raw response from the Create request.
+const TestCreateSubnetsResponseRaw = `
+{
+    "subnets": [
+        {
+            "cidr": "203.0.113.0/29",
+            "id": 112233,
+            "project_id": "9c97bdc75295493096cf5edcb8c37933",
+            "region": "ru-2",
+            "status": "DOWN"
+        },
+        {
+            "cidr": "198.51.100.0/29",
+            "id": 112234,
+            "project_id": "9c97bdc75295493096cf5edcb8c37933",
+            "region": "ru-1",
+            "status": "DOWN"
+        }
+    ]
+}
+`
+
+// TestCreateSubnetResponse represents the unmarshalled TestCreateSubnetsResponseRaw response.
+var TestCreateSubnetResponse = []*subnets.Subnet{
+	{
+		CIDR:      "203.0.113.0/29",
+		ID:        112233,
+		ProjectID: "9c97bdc75295493096cf5edcb8c37933",
+		Region:    "ru-2",
+		Status:    "DOWN",
+	},
+	{
+		CIDR:      "198.51.100.0/29",
+		ID:        112234,
+		ProjectID: "9c97bdc75295493096cf5edcb8c37933",
+		Region:    "ru-1",
+		Status:    "DOWN",
+	},
+}

selvpcclient/resell/v2/subnets/testing/request_test.go

@@ -2,7 +2,9 @@ package testing
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"net/http"
 	"reflect"
 	"testing"
@@ -93,3 +95,51 @@ func TestListSubnetsSingle(t *testing.T) {
 		t.Fatalf("expected %#v, but got %#v", expected, actual)
 	}
 }
+
+func TestCreateSubnets(t *testing.T) {
+	testEnv := testutils.SetupTestEnv()
+	defer testEnv.TearDownTestEnv()
+	testEnv.NewTestResellV2Client()
+	testEnv.Mux.HandleFunc("/resell/v2/subnets/projects/9c97bdc75295493096cf5edcb8c37933", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Add("Content-Type", "application/json")
+		fmt.Fprintf(w, TestCreateSubnetsResponseRaw)
+
+		if r.Method != http.MethodPost {
+			t.Fatalf("expected %s method but got %s", http.MethodPost, r.Method)
+		}
+
+		b, err := ioutil.ReadAll(r.Body)
+		if err != nil {
+			t.Errorf("unable to read the request body: %v", err)
+		}
+
+		var actualRequest interface{}
+		err = json.Unmarshal(b, &actualRequest)
+		if err != nil {
+			t.Errorf("unable to unmarshal the request body: %v", err)
+		}
+
+		var expectedRequest interface{}
+		err = json.Unmarshal([]byte(TestCreateSubnetsOptsRaw), &expectedRequest)
+		if err != nil {
+			t.Errorf("unable to unmarshal expected raw response: %v", err)
+		}
+
+		if !reflect.DeepEqual(actualRequest, expectedRequest) {
+			t.Fatalf("expected %#v create options, but got %#v", expectedRequest, actualRequest)
+		}
+	})
+
+	ctx := context.Background()
+	createOpts := TestCreateSubnetsOpts
+	actualResponse, _, err := subnets.Create(ctx, testEnv.Client, "9c97bdc75295493096cf5edcb8c37933", createOpts)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expectedResponse := TestCreateSubnetResponse
+
+	if !reflect.DeepEqual(actualResponse, expectedResponse) {
+		t.Fatalf("expected %#v, but got %#v", actualResponse, expectedResponse)
+	}
+}

selvpcclient/selvpc.go

@@ -18,8 +18,17 @@ const (
 
 	// DefaultUserAgent contains basic user agent that will be used in queries.
 	DefaultUserAgent = "selvpcclient/" + AppVersion
+
+	// IPv4 represents IP version 4.
+	IPv4 IPVersion = "ipv4"
+
+	// IPv6 represents IP version 6.
+	IPv6 IPVersion = "ipv6"
 )
 
+// IPVersion represents a type for the IP versions of the Resell API.
+type IPVersion string
+
 // ServiceClient stores details that are needed to work with different Selectel VPC APIs.
 type ServiceClient struct {
 	// HTTPClient represents an initialized HTTP client that will be used to do requests.