Check whether we are already attached/detached before hot attach/detach

nagiesek · nagiesek · commit 6d67a3085946 · 2019-05-01T16:28:37.000-07:00
diff --git a/hnsendpoint.go b/hnsendpoint.go
@@ -39,11 +39,21 @@ func HNSListEndpointRequest() ([]HNSEndpoint, error) {
 
 // HotAttachEndpoint makes a HCS Call to attach the endpoint to the container
 func HotAttachEndpoint(containerID string, endpointID string) error {
+	endpoint, err := GetHNSEndpointByID(endpointID)
+	isAttached, err := endpoint.IsAttached(containerID)
+	if isAttached {
+		return err
+	}
 	return modifyNetworkEndpoint(containerID, endpointID, Add)
 }
 
 // HotDetachEndpoint makes a HCS Call to detach the endpoint from the container
 func HotDetachEndpoint(containerID string, endpointID string) error {
+	endpoint, err := GetHNSEndpointByID(endpointID)
+	isAttached, err := endpoint.IsAttached(containerID)
+	if !isAttached {
+		return err
+	}
 	return modifyNetworkEndpoint(containerID, endpointID, Remove)
 }
 
diff --git a/internal/hns/hnsendpoint.go b/internal/hns/hnsendpoint.go
@@ -3,6 +3,7 @@ package hns
 import (
 	"encoding/json"
 	"net"
+	"strings"
 
 	"github.com/sirupsen/logrus"
 )
@@ -94,6 +95,27 @@ func GetHNSEndpointByName(endpointName string) (*HNSEndpoint, error) {
 	return nil, EndpointNotFoundError{EndpointName: endpointName}
 }
 
+type endpointAttachInfo struct {
+	SharedContainers json.RawMessage `json:",omitempty"`
+}
+
+func (endpoint *HNSEndpoint) IsAttached(vID string) (bool, error) {
+	attachInfo := endpointAttachInfo{}
+	err := hnsCall("GET", "/endpoints/"+endpoint.Id, "", &attachInfo)
+
+	// Return false allows us to just return the err
+	if err != nil {
+		return false, err
+	}
+
+	if strings.Contains(strings.ToLower(string(attachInfo.SharedContainers)), strings.ToLower(vID)) {
+		return true, nil
+	}
+
+	return false, nil
+
+}
+
 // Create Endpoint by sending EndpointRequest to HNS. TODO: Create a separate HNS interface to place all these methods
 func (endpoint *HNSEndpoint) Create() (*HNSEndpoint, error) {
 	operation := "Create"
diff --git a/internal/hns/hnsfuncs.go b/internal/hns/hnsfuncs.go
@@ -9,23 +9,30 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
-func hnsCall(method, path, request string, returnResponse interface{}) error {
+func hnsCallRawResponse(method, path, request string) (*hnsResponse, error) {
 	var responseBuffer *uint16
 	logrus.Debugf("[%s]=>[%s] Request : %s", method, path, request)
 
 	err := _hnsCall(method, path, request, &responseBuffer)
 	if err != nil {
-		return hcserror.New(err, "hnsCall ", "")
+		return nil, hcserror.New(err, "hnsCall ", "")
 	}
 	response := interop.ConvertAndFreeCoTaskMemString(responseBuffer)
 
 	hnsresponse := &hnsResponse{}
 	if err = json.Unmarshal([]byte(response), &hnsresponse); err != nil {
-		return err
+		return nil, err
 	}
+	return hnsresponse, nil
+}
 
+func hnsCall(method, path, request string, returnResponse interface{}) error {
+	hnsresponse, err := hnsCallRawResponse(method, path, request)
+	if err != nil {
+		return fmt.Errorf("failed during hnsCallRawResponse: %v", err)
+	}
 	if !hnsresponse.Success {
-		return fmt.Errorf("HNS failed with error : %s", hnsresponse.Error)
+		return fmt.Errorf("hns failed with error : %s", hnsresponse.Error)
 	}
 
 	if len(hnsresponse.Output) == 0 {
