3026: Add support for s3 data importer inheriting service account cre…

…dentials

api/openapi-spec/swagger.json

@@ -4891,6 +4891,10 @@
       "description": "SecretRef provides the secret reference needed to access the S3 source",
       "type": "string"
      },
+     "serviceAccountName": {
+      "description": "ServiceAccountName provides the SAN needed if we want to use chain creds for S3 access (optional, if SecretRef supplied)",
+      "type": "string"
+     },
      "url": {
       "description": "URL is the url of the S3 source",
       "type": "string",

cmd/cdi-importer/importer.go

@@ -255,6 +255,7 @@ func newDataSource(source string, contentType string, volumeMode v1.PersistentVo
 	ep, _ := util.ParseEnvVar(common.ImporterEndpoint, false)
 	acc, _ := util.ParseEnvVar(common.ImporterAccessKeyID, false)
 	sec, _ := util.ParseEnvVar(common.ImporterSecretKey, false)
+	service_account, _ := util.ParseEnvVar(common.ImporterServiceAccountName, false)
 	keyf, _ := util.ParseEnvVar(common.ImporterGoogleCredentialFileVar, false)
 	diskID, _ := util.ParseEnvVar(common.ImporterDiskID, false)
 	uuid, _ := util.ParseEnvVar(common.ImporterUUID, false)
@@ -271,34 +272,45 @@ func newDataSource(source string, contentType string, volumeMode v1.PersistentVo
 	case cc.SourceHTTP:
 		ds, err := importer.NewHTTPDataSource(getHTTPEp(ep), acc, sec, certDir, cdiv1.DataVolumeContentType(contentType))
 		if err != nil {
-			errorCannotConnectDataSource(err, "http")
+			errorCannotConnectDataSource(err, cc.SourceHTTP)
 		}
 		return ds
 	case cc.SourceImageio:
 		ds, err := importer.NewImageioDataSource(ep, acc, sec, certDir, diskID, currentCheckpoint, previousCheckpoint)
 		if err != nil {
-			errorCannotConnectDataSource(err, "imageio")
+			errorCannotConnectDataSource(err, cc.SourceImageio)
 		}
 		return ds
 	case cc.SourceRegistry:
 		ds := importer.NewRegistryDataSource(ep, acc, sec, certDir, insecureTLS)
 		return ds
 	case cc.SourceS3:
-		ds, err := importer.NewS3DataSource(ep, acc, sec, certDir)
+		var (
+			ds  *importer.S3DataSource
+			err error
+		)
+		if service_account != "" {
+			// use this as a flag to say the user has a SAN set up with creds that IRSA will read
+			klog.Infof("Attempting to create your S3 Data Source with cloud provider creds.\n")
+			ds, err = importer.NewChainCredentialsS3DataSource(ep, certDir)
+		} else {
+			// default behaviour of using supplied access key and secret key to configure S3 client
+			ds, err = importer.NewS3DataSource(ep, acc, sec, certDir)
+		}
 		if err != nil {
-			errorCannotConnectDataSource(err, "s3")
+			errorCannotConnectDataSource(err, cc.SourceS3)
 		}
 		return ds
 	case cc.SourceGCS:
 		ds, err := importer.NewGCSDataSource(ep, keyf)
 		if err != nil {
-			errorCannotConnectDataSource(err, "gcs")
+			errorCannotConnectDataSource(err, cc.SourceGCS)
 		}
 		return ds
 	case cc.SourceVDDK:
 		ds, err := importer.NewVDDKDataSource(ep, acc, sec, thumbprint, uuid, backingFile, currentCheckpoint, previousCheckpoint, finalCheckpoint, volumeMode)
 		if err != nil {
-			errorCannotConnectDataSource(err, "vddk")
+			errorCannotConnectDataSource(err, cc.SourceVDDK)
 		}
 		return ds
 	default:

pkg/common/common.go

@@ -111,6 +111,8 @@ const (
 	ImporterAccessKeyID = "IMPORTER_ACCESS_KEY_ID"
 	// ImporterSecretKey provides a constant to capture our env variable "IMPORTER_SECRET_KEY"
 	ImporterSecretKey = "IMPORTER_SECRET_KEY"
+	// ImporterSecretKey provides a constant to capture our env variable "IMPORTER_SECRET_KEY"
+	ImporterServiceAccountName = "IMPORTER_SERVICE_ACCOUNT_NAME"
 	// ImporterImageSize provides a constant to capture our env variable "IMPORTER_IMAGE_SIZE"
 	ImporterImageSize = "IMPORTER_IMAGE_SIZE"
 	// ImporterCertDirVar provides a constant to capture our env variable "IMPORTER_CERT_DIR"

pkg/importer/s3-datasource.go

@@ -21,8 +21,10 @@ import (
 )
 
 const (
-	s3FolderSep = "/"
-	httpScheme  = "http"
+	s3FolderSep    = "/"
+	httpScheme     = "http"
+	emptyAccessKey = ""
+	emptySecretKey = ""
 )
 
 // S3Client is the interface to the used S3 client.
@@ -53,7 +55,7 @@ type S3DataSource struct {
 }
 
 // NewS3DataSource creates a new instance of the S3DataSource
-func NewS3DataSource(endpoint, accessKey, secKey string, certDir string) (*S3DataSource, error) {
+func NewS3DataSource(endpoint string, accessKey string, secKey string, certDir string) (*S3DataSource, error) {
 	ep, err := ParseEndpoint(endpoint)
 	if err != nil {
 		return nil, errors.Wrapf(err, fmt.Sprintf("unable to parse endpoint %q", endpoint))
@@ -70,6 +72,36 @@ func NewS3DataSource(endpoint, accessKey, secKey string, certDir string) (*S3Dat
 	}, nil
 }
 
+// NewS3DataSource creates a new instance of the S3DataSource using chain credentials
+func NewChainCredentialsS3DataSource(endpoint, certDir string) (*S3DataSource, error) {
+	/*
+		Quick Note on IRSA credential chain:
+			When you initialize a new service client without providing any credential arguments, the SDK uses the default credential provider chain to find AWS credentials. The SDK uses the first provider in the chain that returns credentials without an error. The default provider chain looks for credentials in the following order:
+
+				- Environment variables.  (* set when a `serviceAccountName` is supplied)
+
+				- Shared credentials file.
+
+				- If your application uses an ECS task definition or RunTask API operation, IAM role for tasks.
+
+				- If your application is running on an Amazon EC2 instance, IAM role for Amazon EC2.
+	*/
+	ep, err := ParseEndpoint(endpoint)
+	if err != nil {
+		return nil, errors.Wrapf(err, fmt.Sprintf("unable to parse endpoint %q", endpoint))
+	}
+	s3Reader, err := createS3Reader(ep, emptyAccessKey, emptySecretKey, certDir)
+	if err != nil {
+		return nil, err
+	}
+	return &S3DataSource{
+		ep:        ep,
+		accessKey: emptyAccessKey,
+		secKey:    emptySecretKey,
+		s3Reader:  s3Reader,
+	}, nil
+}
+
 // Info is called to get initial information about the data.
 func (sd *S3DataSource) Info() (ProcessingPhase, error) {
 	var err error
@@ -140,7 +172,7 @@ func (sd *S3DataSource) Close() error {
 	return err
 }
 
-func createS3Reader(ep *url.URL, accessKey, secKey string, certDir string) (io.ReadCloser, error) {
+func createS3Reader(ep *url.URL, accessKey string, secKey string, certDir string) (io.ReadCloser, error) {
 	klog.V(3).Infoln("Using S3 client to get data")
 
 	endpoint := ep.Host
@@ -168,31 +200,38 @@ func createS3Reader(ep *url.URL, accessKey, secKey string, certDir string) (io.R
 	return objectReader, nil
 }
 
-func getS3Client(endpoint, accessKey, secKey string, certDir string, urlScheme string) (S3Client, error) {
+func getS3Client(endpoint string, accessKey string, secKey string, certDir string, urlScheme string) (S3Client, error) {
 	// Adding certs using CustomCABundle will overwrite the SystemCerts, so we opt by creating a custom HTTPClient
 	httpClient, err := createHTTPClient(certDir)
 
 	if err != nil {
 		return nil, errors.Wrap(err, "Error creating http client for s3")
 	}
+	var creds *credentials.Credentials = nil
+	if accessKey != emptyAccessKey && secKey != emptySecretKey {
+		creds = credentials.NewStaticCredentials(accessKey, secKey, "")
+	}
 
-	creds := credentials.NewStaticCredentials(accessKey, secKey, "")
 	region := extractRegion(endpoint)
 	disableSSL := false
 	// Disable SSL for http endpoint. This should cause the s3 client to create http requests.
 	if urlScheme == httpScheme {
 		disableSSL = true
 	}
-
-	sess, err := session.NewSession(&aws.Config{
+	sessionConfig := &aws.Config{
 		Region:           aws.String(region),
 		Endpoint:         aws.String(endpoint),
-		Credentials:      creds,
 		S3ForcePathStyle: aws.Bool(true),
 		HTTPClient:       httpClient,
 		DisableSSL:       &disableSSL,
-	},
-	)
+	}
+	if creds != nil {
+		sessionConfig.Credentials = creds
+	} else {
+		// recommended value to set when relying on credential chains
+		sessionConfig.CredentialsChainVerboseErrors = aws.Bool(true)
+	}
+	sess, err := session.NewSession(sessionConfig)
 	if err != nil {
 		return nil, err
 	}

staging/src/kubevirt.io/containerized-data-importer-api/pkg/apis/core/v1beta1/types.go

@@ -169,6 +169,9 @@ type DataVolumeSourceS3 struct {
 	URL string `json:"url"`
 	//SecretRef provides the secret reference needed to access the S3 source
 	SecretRef string `json:"secretRef,omitempty"`
+	//ServiceAccountName provides the SAN needed if we want to use chain creds for S3 access (optional, if SecretRef supplied)
+	// +optional
+	ServiceAccountName string `json:"serviceAccountName,omitempty"`
 	// CertConfigMap is a configmap reference, containing a Certificate Authority(CA) public key, and a base64 encoded pem certificate
 	// +optional
 	CertConfigMap string `json:"certConfigMap,omitempty"`