package management import ( "bytes" "crypto/tls" "fmt" "net/http" ) const ( msVersionHeader = "x-ms-version" requestIDHeader = "x-ms-request-id" uaHeader = "User-Agent" contentHeader = "Content-Type" defaultContentHeaderValue = "application/xml" ) func (client client) SendAzureGetRequest(url string) ([]byte, error) { resp, err := client.sendAzureRequest("GET", url, "", nil) if err != nil { return nil, err } return getResponseBody(resp) } func (client client) SendAzurePostRequest(url string, data []byte) (OperationID, error) { return client.doAzureOperation("POST", url, "", data) } func (client client) SendAzurePostRequestWithReturnedResponse(url string, data []byte) ([]byte, error) { resp, err := client.sendAzureRequest("POST", url, "", data) if err != nil { return nil, err } return getResponseBody(resp) } func (client client) SendAzurePutRequest(url, contentType string, data []byte) (OperationID, error) { return client.doAzureOperation("PUT", url, contentType, data) } func (client client) SendAzureDeleteRequest(url string) (OperationID, error) { return client.doAzureOperation("DELETE", url, "", nil) } func (client client) doAzureOperation(method, url, contentType string, data []byte) (OperationID, error) { response, err := client.sendAzureRequest(method, url, contentType, data) if err != nil { return "", err } return getOperationID(response) } func getOperationID(response *http.Response) (OperationID, error) { requestID := response.Header.Get(requestIDHeader) if requestID == "" { return "", fmt.Errorf("Could not retrieve operation id from %q header", requestIDHeader) } return OperationID(requestID), nil } // sendAzureRequest constructs an HTTP client for the request, sends it to the // management API and returns the response or an error. func (client client) sendAzureRequest(method, url, contentType string, data []byte) (*http.Response, error) { if method == "" { return nil, fmt.Errorf(errParamNotSpecified, "method") } if url == "" { return nil, fmt.Errorf(errParamNotSpecified, "url") } httpClient, err := client.createHTTPClient() if err != nil { return nil, err } response, err := client.sendRequest(httpClient, url, method, contentType, data, 5) if err != nil { return nil, err } return response, nil } // createHTTPClient creates an HTTP Client configured with the key pair for // the subscription for this client. func (client client) createHTTPClient() (*http.Client, error) { cert, err := tls.X509KeyPair(client.publishSettings.SubscriptionCert, client.publishSettings.SubscriptionKey) if err != nil { return nil, err } return &http.Client{ Transport: &http.Transport{ Proxy: http.ProxyFromEnvironment, TLSClientConfig: &tls.Config{ Renegotiation: tls.RenegotiateOnceAsClient, Certificates: []tls.Certificate{cert}, }, }, }, nil } // sendRequest sends a request to the Azure management API using the given // HTTP client and parameters. It returns the response from the call or an // error. func (client client) sendRequest(httpClient *http.Client, url, requestType, contentType string, data []byte, numberOfRetries int) (*http.Response, error) { absURI := client.createAzureRequestURI(url) for { request, reqErr := client.createAzureRequest(absURI, requestType, contentType, data) if reqErr != nil { return nil, reqErr } response, err := httpClient.Do(request) if err != nil { if numberOfRetries == 0 { return nil, err } return client.sendRequest(httpClient, url, requestType, contentType, data, numberOfRetries-1) } if response.StatusCode == http.StatusTemporaryRedirect { // ASM's way of moving traffic around, see https://msdn.microsoft.com/en-us/library/azure/ee460801.aspx // Only handled automatically for GET/HEAD requests. This is for the rest of the http verbs. u, err := response.Location() if err != nil { return response, fmt.Errorf("Redirect requested but location header could not be retrieved: %v", err) } absURI = u.String() continue // re-issue request } if response.StatusCode >= http.StatusBadRequest { body, err := getResponseBody(response) if err != nil { // Failed to read the response body return nil, err } azureErr := getAzureError(body) if azureErr != nil { if numberOfRetries == 0 { return nil, azureErr } return client.sendRequest(httpClient, url, requestType, contentType, data, numberOfRetries-1) } } return response, nil } } // createAzureRequestURI constructs the request uri using the management API endpoint and // subscription ID associated with the client. func (client client) createAzureRequestURI(url string) string { return fmt.Sprintf("%s/%s/%s", client.config.ManagementURL, client.publishSettings.SubscriptionID, url) } // createAzureRequest packages up the request with the correct set of headers and returns // the request object or an error. func (client client) createAzureRequest(url string, requestType string, contentType string, data []byte) (*http.Request, error) { var request *http.Request var err error if data != nil { body := bytes.NewBuffer(data) request, err = http.NewRequest(requestType, url, body) } else { request, err = http.NewRequest(requestType, url, nil) } if err != nil { return nil, err } request.Header.Set(msVersionHeader, client.config.APIVersion) request.Header.Set(uaHeader, client.config.UserAgent) if contentType != "" { request.Header.Set(contentHeader, contentType) } else { request.Header.Set(contentHeader, defaultContentHeaderValue) } return request, nil }