This change adds a bare-bones azure module.

For a project I'm working on I have been writing Terratest style code to
help make assertions about infrastructure in Azure. I want to contribute
these back to Terratest to give back to the awesome open source
community you have going here.

I am initially submitting a subset of the work I have done in order to
get initial feedback. Once this PR is merged I'll go ahead and update
the remaining modules that I have to be consistent with the PR comments
provided here.

Modules in this commit:
* Azure Container Registry - Webhook + Network ACL queries
* Azure Networking - VNET/Subnet queries

Modules that I will contribute in follow on PRs:
* Azure CLI - Log into local azure CLI
* WebApp - Query for WebApp config and CD Webhook metadata
* KeyVault - Inspect network ACLs for KeyVault

modules/azure/acr.go

@@ -0,0 +1,101 @@
+package azure
+
+import (
+	"context"
+	"testing"
+
+	"github.com/Azure/azure-sdk-for-go/services/containerregistry/mgmt/2017-10-01/containerregistry"
+)
+
+func registriesClientE(subscriptionID string) (*containerregistry.RegistriesClient, error) {
+	authorizer, err := DeploymentServicePrincipalAuthorizer()
+	if err != nil {
+		return nil, err
+	}
+	client := containerregistry.NewRegistriesClient(subscriptionID)
+	client.Authorizer = authorizer
+	return &client, nil
+}
+
+func webhookClientE(subscriptionID string) (*containerregistry.WebhooksClient, error) {
+	authorizer, err := DeploymentServicePrincipalAuthorizer()
+	if err != nil {
+		return nil, err
+	}
+	client := containerregistry.NewWebhooksClient(subscriptionID)
+	client.Authorizer = authorizer
+	return &client, nil
+}
+
+// ACRNetworkAclsE - Return the newtwork ACLs for an ACR instance
+func ACRNetworkAclsE(subscriptionID string, resourceGroupName string, acrName string) (*containerregistry.NetworkRuleSet, error) {
+
+	client, err := registriesClientE(subscriptionID)
+	if err != nil {
+		return nil, err
+	}
+
+	acr, err := client.Get(context.Background(), resourceGroupName, acrName)
+	if err != nil {
+		return nil, err
+	}
+
+	return acr.NetworkRuleSet, nil
+}
+
+// ACRNetworkAcls - Like ACRNetworkAclsE but fails in the case an error is returned
+func ACRNetworkAcls(t *testing.T, subscriptionID string, resourceGroupName string, acrName string) *containerregistry.NetworkRuleSet {
+	acls, err := ACRNetworkAclsE(subscriptionID, resourceGroupName, acrName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return acls
+}
+
+// ACRWebHookE - Return ACR Webhook definition
+func ACRWebHookE(subscriptionID string, resourceGroupName string, acrName string, webhookName string) (*containerregistry.Webhook, error) {
+	client, err := webhookClientE(subscriptionID)
+	if err != nil {
+		return nil, err
+	}
+
+	webhook, err := client.Get(context.Background(), resourceGroupName, acrName, webhookName)
+	if err != nil {
+		return nil, err
+	}
+
+	return &webhook, nil
+}
+
+// ACRWebHook - Like ACRWebHookE but fails in the case an error is returned
+func ACRWebHook(t *testing.T, subscriptionID string, resourceGroupName string, acrName string, webhookName string) *containerregistry.Webhook {
+	webhooks, err := ACRWebHookE(subscriptionID, resourceGroupName, acrName, webhookName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return webhooks
+}
+
+// ACRWebHookCallbackE - Get callback config for a webhook
+func ACRWebHookCallbackE(subscriptionID string, resourceGroupName string, acrName string, webhookName string) (*containerregistry.CallbackConfig, error) {
+	client, err := webhookClientE(subscriptionID)
+	if err != nil {
+		return nil, err
+	}
+
+	webhookCallback, err := client.GetCallbackConfig(context.Background(), resourceGroupName, acrName, webhookName)
+	if err != nil {
+		return nil, err
+	}
+
+	return &webhookCallback, nil
+}
+
+// ACRWebHookCallback - Like ACRWebHookCallbackE but fails in the case an error is returned
+func ACRWebHookCallback(t *testing.T, subscriptionID string, resourceGroupName string, acrName string, webhookName string) *containerregistry.CallbackConfig {
+	webhookCallback, err := ACRWebHookCallbackE(subscriptionID, resourceGroupName, acrName, webhookName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return webhookCallback
+}

modules/azure/authorizer.go

@@ -0,0 +1,33 @@
+package azure
+
+import (
+	"os"
+
+	"github.com/Azure/go-autorest/autorest"
+	"github.com/Azure/go-autorest/autorest/adal"
+	az "github.com/Azure/go-autorest/autorest/azure"
+)
+
+// DeploymentServicePrincipalAuthorizer - Returns an authorizer configured with the service principal
+// used to execute the terraform commands
+func DeploymentServicePrincipalAuthorizer() (autorest.Authorizer, error) {
+	return ServicePrincipalAuthorizer(
+		os.Getenv("ARM_CLIENT_ID"),
+		os.Getenv("ARM_CLIENT_SECRET"),
+		az.PublicCloud.ResourceManagerEndpoint)
+}
+
+// ServicePrincipalAuthorizer - Configures a service principal authorizer that can be used to create bearer tokens
+func ServicePrincipalAuthorizer(clientID string, clientSecret string, resource string) (autorest.Authorizer, error) {
+	oauthConfig, err := adal.NewOAuthConfig(az.PublicCloud.ActiveDirectoryEndpoint, os.Getenv("ARM_TENANT_ID"))
+	if err != nil {
+		return nil, err
+	}
+
+	token, err := adal.NewServicePrincipalToken(*oauthConfig, clientID, clientSecret, resource)
+	if err != nil {
+		return nil, err
+	}
+
+	return autorest.NewBearerAuthorizer(token), nil
+}

modules/azure/azure.go

@@ -0,0 +1,4 @@
+package azure
+
+// azure - This package contains terratest functions that make interacting with Microsoft's Azure
+// platform simpler

modules/azure/network.go

@@ -0,0 +1,49 @@
+package azure
+
+import (
+	"context"
+	"testing"
+
+	"github.com/Azure/azure-sdk-for-go/services/network/mgmt/2018-12-01/network"
+)
+
+func vnetClient(subscriptionID string) (*network.VirtualNetworksClient, error) {
+	authorizer, err := DeploymentServicePrincipalAuthorizer()
+	if err != nil {
+		return nil, err
+	}
+
+	client := network.NewVirtualNetworksClient(subscriptionID)
+	client.Authorizer = authorizer
+	return &client, err
+}
+
+// VnetSubnetsListE - Return the subnets that exist wihin a given VNET
+func VnetSubnetsListE(subscriptionID string, resourceGroupName string, vnetName string) ([]string, error) {
+
+	client, err := vnetClient(subscriptionID)
+	if err != nil {
+		return nil, err
+	}
+
+	vnet, err := client.Get(context.Background(), resourceGroupName, vnetName, "")
+	if err != nil {
+		return nil, err
+	}
+
+	subnets := make([]string, len(*vnet.VirtualNetworkPropertiesFormat.Subnets))
+	for index, subnet := range *vnet.VirtualNetworkPropertiesFormat.Subnets {
+		subnets[index] = *subnet.ID
+	}
+
+	return subnets, nil
+}
+
+// VnetSubnetsList - Like VnetSubnetsListE but fails in the case an error is returned
+func VnetSubnetsList(t *testing.T, subscriptionID string, resourceGroupName string, vnetName string) []string {
+	subnets, err := VnetSubnetsListE(subscriptionID, resourceGroupName, vnetName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return subnets
+}