Merge pull request #4758 from hashicorp/f-azurerm-poll-indefinitely

provider/azurerm: Poll indefinitely if no error

builtin/providers/azurerm/provider.go

@@ -2,9 +2,11 @@ package azurerm
 
 import (
 	"fmt"
+	"log"
 	"net/http"
 	"strings"
 
+	"github.com/Azure/azure-sdk-for-go/Godeps/_workspace/src/github.com/Azure/go-autorest/autorest"
 	"github.com/hashicorp/terraform/helper/mutexkv"
 	"github.com/hashicorp/terraform/helper/schema"
 	"github.com/hashicorp/terraform/terraform"
@@ -112,10 +114,47 @@ func registerAzureResourceProvidersWithSubscription(config *Config, client *ArmC
 	return nil
 }
 
+// azureRMNormalizeLocation is a function which normalises human-readable region/location
+// names (e.g. "West US") to the values used and returned by the Azure API (e.g. "westus").
+// In state we track the API internal version as it is easier to go from the human form
+// to the canonical form than the other way around.
 func azureRMNormalizeLocation(location interface{}) string {
 	input := location.(string)
 	return strings.Replace(strings.ToLower(input), " ", "", -1)
 }
 
+// pollIndefinitelyAsNeeded is a terrible hack which is necessary because the Azure
+// Storage API (and perhaps others) can have response times way beyond the default
+// retry timeouts, with no apparent upper bound. This effectively causes the client
+// to continue polling when it reaches the configured timeout. My investigations
+// suggest that this is neccesary when deleting and recreating a storage account with
+// the same name in a short (though undetermined) time period.
+//
+// It is possible that this will give Terraform the appearance of being slow in
+// future: I have attempted to mitigate this by logging whenever this happens. We
+// may want to revisit this with configurable timeouts in the future as clearly
+// unbounded wait loops is not ideal. It does seem preferable to the current situation
+// where our polling loop will time out _with an operation in progress_, but no ID
+// for the resource - so the state will not know about it, and conflicts will occur
+// on the next run.
+func pollIndefinitelyAsNeeded(client autorest.Client, response *http.Response, acceptableCodes ...int) (*http.Response, error) {
+	var resp *http.Response
+	var err error
+
+	for {
+		resp, err = client.PollAsNeeded(response, acceptableCodes...)
+		if err != nil {
+			if resp.StatusCode != http.StatusAccepted {
+				log.Printf("[DEBUG] Starting new polling loop for %q", response.Request.URL.Path)
+				continue
+			}
+
+			return resp, err
+		}
+
+		return resp, nil
+	}
+}
+
 // armMutexKV is the instance of MutexKV for ARM resources
 var armMutexKV = mutexkv.NewMutexKV()