AppsListPublishingCredentialsFuture.Result() panics after 16.2.1 -> 17.x.x upgrade

[katbyte]

Hello,

Looking to update to v17 of the SDK but it appears AppsListPublishingCredentialsFuture.Result() now panics. Switching back to 16.2.1 causes the code runs just fine.

I have now tried versions 17.0.0, 17.1.0, 17.2.0, 17.3.0, 17.4.0 and they all panic.

The Panic:

[13:02:53] kt@snowbook:~/hashi/..3../terraform-providers/terraform-provider-azurerm$ make fmt; make testacc TEST=./azurerm TESTARGS=-test.run=TestAccDataSourceAzureRMAppService_basic
gofmt -w $(find . -name '*.go' |grep -v vendor)
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./azurerm -v -test.run=TestAccDataSourceAzureRMAppService_basic -timeout 180m
=== RUN   TestAccDataSourceAzureRMAppService_basic
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x10 pc=0x1bf8bf1]

goroutine 238 [running]:
github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/Azure/azure-sdk-for-go/services/web/mgmt/2016-09-01/web.(*AppsListPublishingCredentialsFuture).Result(0xc420dbc190, 0x2b55060, 0xc42064a460, 0x2b58220, 0xc420d427a0, 0x0, 0x0, 0xdf8475800, 0x34630b8a000, 0x3, ...)
	/Users/kt/hashi/go/src/github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/Azure/azure-sdk-for-go/services/web/mgmt/2016-09-01/web/models.go:4070 +0x251
github.com/terraform-providers/terraform-provider-azurerm/azurerm.resourceArmAppServiceRead(0xc4202171f0, 0x28ce2e0, 0xc420d3c000, 0x2b62f00, 0xc4200438c0)
	/Users/kt/hashi/go/src/github.com/terraform-providers/terraform-provider-azurerm/azurerm/resource_arm_app_service.go:427 +0xedb
github.com/terraform-providers/terraform-provider-azurerm/azurerm.resourceArmAppServiceUpdate(0xc4202171f0, 0x28ce2e0, 0xc420d3c000, 0xc420d427a0, 0x0)
	/Users/kt/hashi/go/src/github.com/terraform-providers/terraform-provider-azurerm/azurerm/resource_arm_app_service.go:374 +0x807
github.com/terraform-providers/terraform-provider-azurerm/azurerm.resourceArmAppServiceCreate(0xc4202171f0, 0x28ce2e0, 0xc420d3c000, 0xc4202171f0, 0x0)
	/Users/kt/hashi/go/src/github.com/terraform-providers/terraform-provider-azurerm/azurerm/resource_arm_app_service.go:254 +0xbc2
github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/helper/schema.(*Resource).Apply(0xc4203082a0, 0xc420530d20, 0xc42031f360, 0x28ce2e0, 0xc420d3c000, 0xc420640501, 0x38, 0x0)
	/Users/kt/hashi/go/src/github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/helper/schema/resource.go:227 +0x35a
github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/helper/schema.(*Provider).Apply(0xc420424e00, 0xc420530780, 0xc420530d20, 0xc42031f360, 0x1, 0x1af35659, 0x0)
	/Users/kt/hashi/go/src/github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/helper/schema/provider.go:283 +0xa4
github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/terraform.(*EvalApply).Eval(0xc420d058c0, 0x2b85180, 0xc420c92b60, 0x2, 0x2, 0x29096f6, 0x4)
	/Users/kt/hashi/go/src/github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/terraform/eval_apply.go:57 +0x22c
github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/terraform.EvalRaw(0x2b559c0, 0xc420d058c0, 0x2b85180, 0xc420c92b60, 0x0, 0x0, 0x0, 0x0)
	/Users/kt/hashi/go/src/github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/terraform/eval.go:53 +0x156
github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/terraform.(*EvalSequence).Eval(0xc42031e540, 0x2b85180, 0xc420c92b60, 0x2, 0x2, 0x29096f6, 0x4)
	/Users/kt/hashi/go/src/github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/terraform/eval_sequence.go:14 +0x7a
github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/terraform.EvalRaw(0x2b55f20, 0xc42031e540, 0x2b85180, 0xc420c92b60, 0x26b8420, 0x38ef722, 0x2651600, 0xc42054cdd0)
	/Users/kt/hashi/go/src/github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/terraform/eval.go:53 +0x156
github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/terraform.Eval(0x2b55f20, 0xc42031e540, 0x2b85180, 0xc420c92b60, 0xc42031e540, 0x2b55f20, 0xc42031e540, 0xc4206aebe0)
	/Users/kt/hashi/go/src/github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/terraform/eval.go:34 +0x4d
github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/terraform.(*Graph).walk.func1(0x2898300, 0xc420516060, 0x0, 0x0)
	/Users/kt/hashi/go/src/github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/terraform/graph.go:126 +0xc26
github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/dag.(*Walker).walkVertex(0xc4203f1f10, 0x2898300, 0xc420516060, 0xc420d22940)
	/Users/kt/hashi/go/src/github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/dag/walk.go:387 +0x3a0
created by github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/dag.(*Walker).Update
	/Users/kt/hashi/go/src/github.com/terraform-providers/terraform-provider-azurerm/vendor/github.com/hashicorp/terraform/dag/walk.go:310 +0x1248
FAIL	github.com/terraform-providers/terraform-provider-azurerm/azurerm	36.682s
make: *** [testacc] Error 1
[13:04:30] kt@snowbook:~/hashi/..3../terraform-providers/terraform-provider-azurerm$

Calling code:

    siteCredFuture, err := client.ListPublishingCredentials(ctx, resGroup, name)
	if err != nil {
		return err
	}
	err = siteCredFuture.WaitForCompletion(ctx, client.Client)
	if err != nil {
		return err
	}
	siteCredResp, err := siteCredFuture.Result(client)
	if err != nil {
		return fmt.Errorf("Error making Read request on AzureRM App Service Site Credential %q: %+v", name, err)
	}

(changing to WaitForCompletionRef does not put a pause to the panic)

[jhendrixMSFT]

@katbyte what version of go-autorest are you using? There were some changes to the futures implementation in v17 that requires an updated go-autorest as well (v10.9+).

[katbyte]

Oh sorry @jhendrixMSFT, I should have thought to include that. Here is what we are using:

[14:59:22] kt@snowbook:~/hashi/..3../terraform-providers/terraform-provider-azurerm$ govendor list | egrep autorest
 v  github.com/Azure/go-autorest/autorest                                                                                 =v10.11.2  v10.11.2
 v  github.com/Azure/go-autorest/autorest/adal                                                                            =v10.11.2  v10.11.2
 v  github.com/Azure/go-autorest/autorest/azure                                                                           =v10.11.2  v10.11.2
 v  github.com/Azure/go-autorest/autorest/azure/cli                                                                       =v10.11.2  v10.11.2
 v  github.com/Azure/go-autorest/autorest/date                                                                            =v10.11.2  v10.11.2
 v  github.com/Azure/go-autorest/autorest/to                                                                              =v10.11.2  v10.11.2
 v  github.com/Azure/go-autorest/autorest/validation                                                                      =v10.11.2  v10.11.2
[14:59:30] kt@snowbook:~/hashi/..3../terraform-providers/terraform-provider-azurerm$

[jhendrixMSFT]

Thanks I can repro this. The HTTP response is a 200 and there are no async operation headers which leads me to believe this operation isn't really a LRO. Still investigating.

[jhendrixMSFT]

@katbyte I have a fix for this in go-autorest, should be merged later today.

[jhendrixMSFT]

Fix is now available in https://github.com/Azure/go-autorest/releases/tag/v10.11.4