velero/pkg/cloudprovider/azure/object_store.go

/*
Copyright 2017 the Heptio Ark contributors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package azure

import (
	"io"
	"os"
	"strings"
	"time"

	storagemgmt "github.com/Azure/azure-sdk-for-go/services/storage/mgmt/2017-10-01/storage"
	"github.com/Azure/azure-sdk-for-go/storage"
	"github.com/Azure/go-autorest/autorest"
	"github.com/Azure/go-autorest/autorest/azure"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"

	"github.com/heptio/ark/pkg/cloudprovider"
)

const (
	resourceGroupConfigKey  = "resourceGroup"
	storageAccountConfigKey = "storageAccount"
)

type objectStore struct {
	blobClient *storage.BlobStorageClient
	log        logrus.FieldLogger
}

func NewObjectStore(logger logrus.FieldLogger) cloudprovider.ObjectStore {
	return &objectStore{log: logger}
}

func getStorageAccountKey(client storagemgmt.AccountsClient, resourceGroup, storageAccount string) (string, error) {
	res, err := client.ListKeys(resourceGroup, storageAccount)
	if err != nil {
		return "", errors.WithStack(err)
	}
	if res.Keys == nil || len(*res.Keys) == 0 {
		return "", errors.New("No storage keys found")
	}

	var storageKey string

	for _, key := range *res.Keys {
		// uppercase both strings for comparison because the ListKeys call returns e.g. "FULL" but
		// the storagemgmt.Full constant in the SDK is defined as "Full".
		if strings.ToUpper(string(key.Permissions)) == strings.ToUpper(string(storagemgmt.Full)) {
			storageKey = *key.Value
			break
		}
	}

	if storageKey == "" {
		return "", errors.New("No storage key with Full permissions found")
	}

	return storageKey, nil
}

func mapLookup(data map[string]string) func(string) string {
	return func(key string) string {
		return data[key]
	}
}

func (o *objectStore) Init(config map[string]string) error {
	// 1. we need AZURE_TENANT_ID, AZURE_CLIENT_ID, AZURE_CLIENT_SECRET, AZURE_SUBSCRIPTION_ID
	envVars, err := getRequiredValues(os.Getenv, tenantIDEnvVar, clientIDEnvVar, clientSecretEnvVar, subscriptionIDEnvVar)
	if err != nil {
		return errors.Wrap(err, "unable to get all required environment variables")
	}

	// 2. we need config["resourceGroup"], config["storageAccount"]
	if _, err := getRequiredValues(mapLookup(config), resourceGroupConfigKey, storageAccountConfigKey); err != nil {
		return errors.Wrap(err, "unable to get all required config values")
	}

	// 3. get SPT
	spt, err := newServicePrincipalToken(envVars[tenantIDEnvVar], envVars[clientIDEnvVar], envVars[clientSecretEnvVar], azure.PublicCloud.ResourceManagerEndpoint)
	if err != nil {
		return errors.Wrap(err, "error getting service principal token")
	}

	// 4. get storageAccountsClient
	storageAccountsClient := storagemgmt.NewAccountsClient(envVars[subscriptionIDEnvVar])
	storageAccountsClient.Authorizer = autorest.NewBearerAuthorizer(spt)

	// 5. get storage key
	storageAccountKey, err := getStorageAccountKey(storageAccountsClient, config[resourceGroupConfigKey], config[storageAccountConfigKey])
	if err != nil {
		return errors.Wrap(err, "error getting storage account key")
	}

	// 6. get storageClient and blobClient
	storageClient, err := storage.NewBasicClient(config[storageAccountConfigKey], storageAccountKey)
	if err != nil {
		return errors.Wrap(err, "error getting storage client")
	}

	blobClient := storageClient.GetBlobService()
	o.blobClient = &blobClient

	return nil
}

func (o *objectStore) PutObject(bucket string, key string, body io.Reader) error {
	container, err := getContainerReference(o.blobClient, bucket)
	if err != nil {
		return err
	}

	blob, err := getBlobReference(container, key)
	if err != nil {
		return err
	}

	return errors.WithStack(blob.CreateBlockBlobFromReader(body, nil))
}

func (o *objectStore) GetObject(bucket string, key string) (io.ReadCloser, error) {
	container, err := getContainerReference(o.blobClient, bucket)
	if err != nil {
		return nil, err
	}

	blob, err := getBlobReference(container, key)
	if err != nil {
		return nil, err
	}

	res, err := blob.Get(nil)
	if err != nil {
		return nil, errors.WithStack(err)
	}

	return res, nil
}

func (o *objectStore) ListCommonPrefixes(bucket string, delimiter string) ([]string, error) {
	container, err := getContainerReference(o.blobClient, bucket)
	if err != nil {
		return nil, err
	}

	params := storage.ListBlobsParameters{
		Delimiter: delimiter,
	}

	res, err := container.ListBlobs(params)
	if err != nil {
		return nil, errors.WithStack(err)
	}

	// Azure returns prefixes inclusive of the last delimiter. We need to strip
	// it.
	ret := make([]string, 0, len(res.BlobPrefixes))
	for _, prefix := range res.BlobPrefixes {
		ret = append(ret, prefix[0:strings.LastIndex(prefix, delimiter)])
	}

	return ret, nil
}

func (o *objectStore) ListObjects(bucket, prefix string) ([]string, error) {
	container, err := getContainerReference(o.blobClient, bucket)
	if err != nil {
		return nil, err
	}

	params := storage.ListBlobsParameters{
		Prefix: prefix,
	}

	res, err := container.ListBlobs(params)
	if err != nil {
		return nil, errors.WithStack(err)
	}

	ret := make([]string, 0, len(res.Blobs))
	for _, blob := range res.Blobs {
		ret = append(ret, blob.Name)
	}

	return ret, nil
}

func (o *objectStore) DeleteObject(bucket string, key string) error {
	container, err := getContainerReference(o.blobClient, bucket)
	if err != nil {
		return err
	}

	blob, err := getBlobReference(container, key)
	if err != nil {
		return err
	}

	return errors.WithStack(blob.Delete(nil))
}

func (o *objectStore) CreateSignedURL(bucket, key string, ttl time.Duration) (string, error) {
	container, err := getContainerReference(o.blobClient, bucket)
	if err != nil {
		return "", err
	}

	blob, err := getBlobReference(container, key)
	if err != nil {
		return "", err
	}

	opts := storage.BlobSASOptions{
		SASOptions: storage.SASOptions{
			Expiry: time.Now().Add(ttl),
		},
		BlobServiceSASPermissions: storage.BlobServiceSASPermissions{
			Read: true,
		},
	}

	return blob.GetSASURI(opts)
}

func getContainerReference(blobClient *storage.BlobStorageClient, bucket string) (*storage.Container, error) {
	container := blobClient.GetContainerReference(bucket)
	if container == nil {
		return nil, errors.Errorf("unable to get container reference for bucket %v", bucket)
	}

	return container, nil
}

func getBlobReference(container *storage.Container, key string) (*storage.Blob, error) {
	blob := container.GetBlobReference(key)
	if blob == nil {
		return nil, errors.Errorf("unable to get blob reference for key %v", key)
	}

	return blob, nil
}