retry on 409 responses

client.go

@@ -89,7 +89,7 @@ func (client Client) dispatchRequest(request *http.Request) ([]byte, error) {
 		// as instructed and retry the request.
 		if err != nil {
 			serverError, ok := errors.Cause(err).(ServerError)
-			if ok && serverError.StatusCode == http.StatusServiceUnavailable {
+			if ok && (serverError.StatusCode == http.StatusServiceUnavailable || serverError.StatusCode == http.StatusConflict) {
 				retryTimeInt, errConv := strconv.Atoi(serverError.Header.Get(RetryAfterHeaderName))
 				if errConv == nil {
 					select {

client_test.go

@@ -78,6 +78,22 @@ func (suite *ClientSuite) TestClientDispatchRequestRetries503(c *gc.C) {
 	c.Check(*server.requests, jc.DeepEquals, expectedRequestsContent)
 }
 
+func (suite *ClientSuite) TestClientDispatchRequestRetries409(c *gc.C) {
+	URI := "/some/url/?param1=test"
+	server := newFlakyServer(URI, 409, NumberOfRetries)
+	defer server.Close()
+	client, err := NewAnonymousClient(server.URL, "1.0")
+	c.Assert(err, jc.ErrorIsNil)
+	content := "content"
+	request, err := http.NewRequest("GET", server.URL+URI, io.NopCloser(strings.NewReader(content)))
+	c.Assert(err, jc.ErrorIsNil)
+
+	_, err = client.dispatchRequest(request)
+
+	c.Assert(err, jc.ErrorIsNil)
+	c.Check(*server.nbRequests, gc.Equals, NumberOfRetries+1)
+}
+
 func (suite *ClientSuite) TestTLSClientDispatchRequestRetries503NilBody(c *gc.C) {
 	URI := "/some/path"
 	server := newFlakyTLSServer(URI, 503, NumberOfRetries)

testing.go

@@ -69,7 +69,7 @@ func newFlakyServer(uri string, code int, nbFlakyResponses int) *flakyServer {
 			errorMsg := fmt.Sprintf("Error 404: page not found (expected '%v', got '%v').", uri, request.URL.String())
 			http.Error(writer, errorMsg, http.StatusNotFound)
 		} else if nbRequests <= nbFlakyResponses {
-			if code == http.StatusServiceUnavailable {
+			if code == http.StatusServiceUnavailable || code == http.StatusConflict {
 				writer.Header().Set("Retry-After", "0")
 			}
 			writer.WriteHeader(code)