chhsiao1981 / azure-sdk-for-go

Microsoft Azure SDK for Go

Azure SDK for Go

azure-sdk-for-go provides Go packages for managing and using Azure services. It has been tested with Go 1.8, 1.9 and 1.10.

To be notified about updates and changes, subscribe to the Azure update feed.

Users of the SDK may prefer to jump right in to our samples repo at github.com/Azure-Samples/azure-sdk-for-go-samples.

Build Details

Most packages in the SDK are generated from Azure API specs using Azure/autorest.go and Azure/autorest. These generated packages depend on the HTTP client implemented at Azure/go-autorest.

The SDK codebase adheres to semantic versioning and thus avoids breaking changes other than at major (x.0.0) releases. However, occasionally Azure API fixes require breaking updates within an individual package; these exceptions are noted in release changelogs.

To more reliably manage dependencies like the Azure SDK in your applications we recommend golang/dep.

Install and Use:

Install

$ go get -u github.com/Azure/azure-sdk-for-go/...

or if you use dep, within your repo run:

$ dep ensure -add github.com/Azure/azure-sdk-for-go

If you need to install Go, follow the official instructions.

Use

For complete examples of many scenarios see Azure-Samples/azure-sdk-for-go-samples.

1. Import a package from the services directory.
2. Create and authenticate a client with a New*Client func, e.g. c := compute.NewVirtualMachinesClient(...).
3. Invoke API methods using the client, e.g. c.CreateOrUpdate(...).
4. Handle responses.

For example, to create a new virtual network (substitute your own values for strings in angle brackets):

Note: For more on authentication and the Authorizer interface see the next section.

package main

import (
	"context"
	"github.com/Azure/azure-sdk-for-go/services/network/mgmt/2017-09-01/network"
	"github.com/Azure/go-autorest/autorest/azure/auth"
	"github.com/Azure/go-autorest/autorest/to"
)

func main() {
	vnetClient := network.NewVirtualNetworksClient("<subscriptionID>")
	authorizer, err := auth.NewAuthorizerFromEnvironment()

	if err == nil {
		vnetClient.Authorizer = authorizer
	}

	vnetClient.CreateOrUpdate(context.Background(),
		"<resourceGroupName>",
		"<vnetName>",
		network.VirtualNetwork{
			Location: to.StringPtr("<azureRegion>"),
			VirtualNetworkPropertiesFormat: &network.VirtualNetworkPropertiesFormat{
				AddressSpace: &network.AddressSpace{
					AddressPrefixes: &[]string{"10.0.0.0/8"},
				},
				Subnets: &[]network.Subnet{
					{
						Name: to.StringPtr("<subnet1Name>"),
						SubnetPropertiesFormat: &network.SubnetPropertiesFormat{
							AddressPrefix: to.StringPtr("10.0.0.0/16"),
						},
					},
					{
						Name: to.StringPtr("<subnet2Name>"),
						SubnetPropertiesFormat: &network.SubnetPropertiesFormat{
							AddressPrefix: to.StringPtr("10.1.0.0/16"),
						},
					},
				},
			},
		})
}

Authentication

Most SDK operations require an OAuth token for authentication and authorization. These are made available in the Go SDK For Azure through types implementing the Authorizer interface. You can get one from Azure Active Directory using the SDK's authentication package. The Authorizer returned should be set as the authorizer for the resource client, as shown in the previous section.

You can get an authorizer in the following ways:

1. From the Environment:

• Use auth.auth.NewAuthorizerFromEnvironment(). This call will try to get an authorizer based on the environment variables with different types of credentials in the following order:

  1. Client Credentials: Uses the AAD App Secret for auth.
  • AZURE_TENANT_ID: Specifies the Tenant to which to authenticate.
  • AZURE_CLIENT_ID: Specifies the app client ID to use.
  • AZURE_CLIENT_SECRET: Specifies the app secret to use.
  2. Client Certificate: Uses a certificate that was configured on the AAD Service Principal.
  • AZURE_TENANT_ID: Specifies the Tenant to which to authenticate.
  • AZURE_CLIENT_ID: Specifies the app client ID to use.
  • AZURE_CERTIFICATE_PATH: Specifies the certificate Path to use.
  • AZURE_CERTIFICATE_PASSWORD: Specifies the certificate password to use.
  3. Username Pasword: Uses a username and a password for auth. This is not recommended. Use Device Flow Auth instead for user interactive acccess.
  • AZURE_TENANT_ID: Specifies the Tenant to which to authenticate.
  • AZURE_CLIENT_ID: Specifies the app client ID to use.
  • AZURE_USERNAME: Specifies the username to use.
  • AZURE_PASSWORD: Specifies the password to use.
  4. MSI: Only available for apps running in Azure. No configuration needed as it leverages the fact that the app is running in Azure. See Azure Managed Service Identity.

• Optionally, the following environment variables can be defined:

  • AZURE_ENVIRONMENT: Specifies the Azure Environment to use. If not set, it defaults to AzurePublicCloud. (Not applicable to MSI based auth)
  • AZURE_AD_RESOURCE: Specifies the AAD resource ID to use. If not set, it defaults to ResourceManagerEndpointwhich allows management operations against Azure Resource Manager.

2. From an Auth File:

• Create a service principal and output the file content using az ad sp create-for-rbac --sdk-auth from the Azure CLI.For more details see az ad sp.
• Set environment variable AZURE_AUTH_LOCATION for finding the file.
• Use auth.NewAuthorizerFromFile() for getting the Authorizer based on the auth file.

3. From Device Flow by configuring auth.DeviceFlowConfig and calling the Authorizer() method.

Note: To authenticate you first need to create a service principal in Azure. To create a new service principal, run az ad sp create-for-rbac -n "<app_name>" in the azure-cli. See these docs for more info. Copy the new principal's ID, secret, and tenant ID for use in your app.

Alternatively, if your apps are running in Azure, you can now leverage the Managed Service Identity.

Versioning

azure-sdk-for-go provides at least a basic Go binding for every Azure API. To provide maximum flexibility to users, the SDK even includes previous versions of Azure APIs which are still in use. This enables us to support users of the most updated Azure datacenters, regional datacenters with earlier APIs, and even on-premises installations of Azure Stack.

SDK versions apply globally and are tracked by git tags. These are in x.y.z form and generally adhere to semantic versioning specifications.

Service API versions are generally represented by a date string and are tracked by offering separate packages for each version. For example, to choose the latest API versions for Compute and Network, use the following imports:

import (
    "github.com/Azure/azure-sdk-for-go/services/compute/mgmt/2017-12-01/compute"
    "github.com/Azure/azure-sdk-for-go/services/network/mgmt/2017-09-01/network"
)

Occasionally service-side changes require major changes to existing versions. These cases are noted in the changelog.

All avilable services and versions are listed under the services/ path in this repo and in GoDoc. Run find ./services -type d -mindepth 3 to list all available service packages.

Profiles

Azure API profiles specify subsets of Azure APIs and versions. Profiles can provide:

• stability for your application by locking to specific API versions; and/or
• compatibility for your application with Azure Stack and regional Azure datacenters.

In the Go SDK, profiles are available under the profiles/ path and their component API versions are aliases to the true service package under services/. You can use them as follows:

import "github.com/Azure/azure-sdk-for-go/profiles/2017-03-09/compute/mgmt/compute"
import "github.com/Azure/azure-sdk-for-go/profiles/2017-03-09/network/mgmt/network"
import "github.com/Azure/azure-sdk-for-go/profiles/2017-03-09/storage/mgmt/storage"

The 2017-03-09 profile is the only one currently available and is for use in hybrid Azure and Azure Stack environments. More profiles are under development.

In addition to versioned profiles, we also provide two special profiles latest and preview. These always include the most recent respective stable or preview API versions for each service, even when updating them to do so causes breaking changes. That is, these do not adhere to semantic versioning rules.

The latest and preview profiles can help you stay up to date with API updates as you build applications. Since they are by definition not stable, however, they should not be used in production apps. Instead, choose the latest specific API version (or an older one if necessary) from the services/ path.

As an example, to automatically use the most recent Compute APIs, use one of the following imports:

import "github.com/Azure/azure-sdk-for-go/profiles/latest/compute/mgmt/compute"
import "github.com/Azure/azure-sdk-for-go/profiles/preview/compute/mgmt/compute"

Inspecting and Debugging

All clients implement some handy hooks to help inspect the underlying requests being made to Azure.

• RequestInspector: View and manipulate the go http.Request before it's sent
• ResponseInspector: View the http.Response received

Here is an example of how these can be used with net/http/httputil to see requests and responses.

vnetClient := network.NewVirtualNetworksClient("<subscriptionID>")
vnetClient.RequestInspector = LogRequest()
vnetClient.ResponseInspector = LogResponse()

...

func LogRequest() autorest.PrepareDecorator {
	return func(p autorest.Preparer) autorest.Preparer {
		return autorest.PreparerFunc(func(r *http.Request) (*http.Request, error) {
			r, err := p.Prepare(r)
			if err != nil {
				log.Println(err)
			}
			dump, _ := httputil.DumpRequestOut(r, true)
			log.Println(string(dump))
			return r, err
		})
	}
}

func LogResponse() autorest.RespondDecorator {
	return func(p autorest.Responder) autorest.Responder {
		return autorest.ResponderFunc(func(r *http.Response) error {
			err := p.Respond(r)
			if err != nil {
				log.Println(err)
			}
			dump, _ := httputil.DumpResponse(r, true)
			log.Println(string(dump))
			return err
		})
	}
}

Resources

• SDK docs are at godoc.org.
• SDK samples are at Azure-Samples/azure-sdk-for-go-samples.
• SDK notifications are published via the Azure update feed.
• Azure API docs are at docs.microsoft.com/rest/api.
• General Azure docs are at docs.microsoft.com/azure.

Other Azure packages for Go

• Azure Storage Blobs - github.com/Azure/azure-storage-blob-go
• Azure Applications Insights - github.com/Microsoft/ApplicationInsights-Go

License

Apache 2.0, see LICENSE.

Contribute

See CONTRIBUTING.md.