#27 Add 422 retry on vm create

skytap/vm.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"log"
+	"net/http"
 	"sort"
 	"time"
 )
@@ -278,10 +279,23 @@ func (s *VMsServiceClient) Create(ctx context.Context, environmentID string, opt
 		return nil, err
 	}
 
+	// Retry to work around 422 errors on creating a vm.
 	var createdEnvironment Environment
-	_, err = s.client.do(ctx, req, &createdEnvironment)
-	if err != nil {
-		return nil, err
+	var makeRequest = true
+	for i := 0; i < s.client.retryCount+1 && makeRequest; i++ {
+		_, err = s.client.do(ctx, req, &createdEnvironment)
+		if err == nil {
+			log.Printf("[INFO] VM created\n")
+			makeRequest = false
+		} else {
+			errorResponse := err.(*ErrorResponse)
+			if http.StatusUnprocessableEntity == errorResponse.Response.StatusCode {
+				log.Printf("[INFO] 422 error received: waiting for %d second(s)\n", s.client.retryAfter)
+				time.Sleep(time.Duration(s.client.retryAfter) * time.Second)
+			} else {
+				return nil, err
+			}
+		}
 	}
 
 	// The create method returns an environment. The ID of the VM is not specified.

skytap/vm_test.go

@@ -50,6 +50,88 @@ func TestCreateVM(t *testing.T) {
 	assert.Equal(t, environment.VMs[1], *createdVM, "Bad VM")
 }
 
+func TestCreateVM422(t *testing.T) {
+	request := fmt.Sprintf(`{
+		"template_id": "%d",
+    		"vm_ids": [
+        		"%d"
+    	]
+	}`, 42, 43)
+	response := fmt.Sprintf(string(readTestFile(t, "createVMResponse.json")), 123, 123, 456)
+	requestCounter := 0
+
+	skytap, hs, handler := createClient(t)
+	defer hs.Close()
+
+	*handler = func(rw http.ResponseWriter, req *http.Request) {
+		assert.Equal(t, "/configurations/123", req.URL.Path, "Bad path")
+		assert.Equal(t, "PUT", req.Method, "Bad method")
+
+		body, err := ioutil.ReadAll(req.Body)
+		assert.Nil(t, err, "Bad request body")
+		assert.JSONEq(t, request, string(body), "Bad request body")
+
+		if requestCounter == 0 {
+			rw.WriteHeader(http.StatusUnprocessableEntity)
+		} else {
+			_, err = io.WriteString(rw, response)
+			assert.NoError(t, err)
+		}
+		requestCounter++
+	}
+	opts := &CreateVMRequest{
+		TemplateID: "42",
+		VMID:       "43",
+	}
+
+	createdVM, err := skytap.VMs.Create(context.Background(), "123", opts)
+	assert.Nil(t, err, "Bad API method")
+
+	var environment Environment
+	err = json.Unmarshal([]byte(response), &environment)
+	assert.NoError(t, err)
+	assert.Equal(t, environment.VMs[1], *createdVM, "Bad VM")
+
+	assert.Equal(t, 2, requestCounter)
+}
+
+func TestCreateVMError(t *testing.T) {
+	request := fmt.Sprintf(`{
+		"template_id": "%d",
+    		"vm_ids": [
+        		"%d"
+    	]
+	}`, 42, 43)
+	requestCounter := 0
+
+	skytap, hs, handler := createClient(t)
+	defer hs.Close()
+
+	*handler = func(rw http.ResponseWriter, req *http.Request) {
+		assert.Equal(t, "/configurations/123", req.URL.Path, "Bad path")
+		assert.Equal(t, "PUT", req.Method, "Bad method")
+
+		body, err := ioutil.ReadAll(req.Body)
+		assert.Nil(t, err, "Bad request body")
+		assert.JSONEq(t, request, string(body), "Bad request body")
+
+		rw.WriteHeader(401)
+		requestCounter++
+	}
+	opts := &CreateVMRequest{
+		TemplateID: "42",
+		VMID:       "43",
+	}
+
+	createdVM, err := skytap.VMs.Create(context.Background(), "123", opts)
+	assert.Nil(t, createdVM, "Bad API method")
+	errorResponse := err.(*ErrorResponse)
+
+	assert.Nil(t, errorResponse.RetryAfter)
+	assert.Equal(t, 1, requestCounter)
+	assert.Equal(t, http.StatusUnauthorized, errorResponse.Response.StatusCode)
+}
+
 func TestReadVM(t *testing.T) {
 	response := fmt.Sprintf(string(readTestFile(t, "VMResponse.json")), 456)