Added the implementation for EBS volume discovery on Windows (#49)

* Added the implementation for EBS volume discovery on Windows

* incorporated the review comments. Also fixed the name of the timeout variable.

* incorporated the review comments. Also fixed the name of the timeout variable.

Author: saurabhc123

agent/vendor/github.com/aws/amazon-ecs-agent/ecs-agent/api/resource/ebs_discovery.go

@@ -15,47 +15,55 @@ package resource
 
 import (
 	"context"
-	"errors"
-	"fmt"
 	"strings"
 	"time"
+
+	"github.com/aws/amazon-ecs-agent/ecs-agent/logger"
+
+	"github.com/pkg/errors"
 )
 
 const (
-	ebsnvmeIDTimeoutDuration = 5 * time.Second
-	ebsResourceKeyPrefix     = "ebs-volume:"
-	ScanPeriod               = 500 * time.Millisecond
+	ebsVolumeDiscoveryTimeout = 5 * time.Second
+	ebsResourceKeyPrefix      = "ebs-volume:"
+	ScanPeriod                = 500 * time.Millisecond
 )
 
 var (
 	ErrInvalidVolumeID = errors.New("EBS volume IDs do not match")
 )
 
-// EBSDiscoveryClient is used to scan and validate if an EBS volume is attached on the host instance.
 type EBSDiscoveryClient struct {
 	ctx context.Context
 }
 
-// NewDiscoveryClient creates a new EBSDiscoveryClient object
-func NewDiscoveryClient(ctx context.Context) EBSDiscovery {
+func NewDiscoveryClient(ctx context.Context) *EBSDiscoveryClient {
 	return &EBSDiscoveryClient{
 		ctx: ctx,
 	}
 }
 
 // ScanEBSVolumes will iterate through the entire list of pending EBS volume attachments within the agent state and checks if it's attached on the host.
-func ScanEBSVolumes[T GenericEBSAttachmentObject](pendingAttachments map[string]T, dc EBSDiscovery) []string {
+func ScanEBSVolumes[T GenericEBSAttachmentObject](t map[string]T, dc EBSDiscovery) []string {
 	var err error
 	var foundVolumes []string
-	for key, ebs := range pendingAttachments {
+	for key, ebs := range t {
 		volumeId := strings.TrimPrefix(key, ebsResourceKeyPrefix)
 		deviceName := ebs.GetAttachmentProperties(DeviceName)
 		err = dc.ConfirmEBSVolumeIsAttached(deviceName, volumeId)
 		if err != nil {
-			if !errors.Is(err, ErrInvalidVolumeID) {
-				err = fmt.Errorf("%w; failed to confirm if EBS volume is attached to the host", err)
+			if err == ErrInvalidVolumeID || errors.Cause(err) == ErrInvalidVolumeID {
+				logger.Warn("Found a different EBS volume attached to the host. Expected EBS volume:", logger.Fields{
+					"volumeId":   volumeId,
+					"deviceName": deviceName,
+				})
+			} else {
+				logger.Warn("Failed to confirm if EBS volume is attached to the host. ", logger.Fields{
+					"volumeId":   volumeId,
+					"deviceName": deviceName,
+					"error":      err,
+				})
 			}
-			ebs.SetError(err)
 			continue
 		}
 		foundVolumes = append(foundVolumes, key)

agent/vendor/github.com/aws/amazon-ecs-agent/ecs-agent/api/resource/ebs_discovery_linux.go

@@ -44,7 +44,7 @@ type BDChild struct {
 // 2. On xen-based instance we only check by the device name.
 func (api *EBSDiscoveryClient) ConfirmEBSVolumeIsAttached(deviceName, volumeID string) error {
 	var lsblkOut LsblkOutput
-	ctxWithTimeout, cancel := context.WithTimeout(api.ctx, ebsnvmeIDTimeoutDuration)
+	ctxWithTimeout, cancel := context.WithTimeout(api.ctx, ebsVolumeDiscoveryTimeout)
 	defer cancel()
 
 	// The lsblk command will output the name and volume ID of all block devices on the host in JSON format

agent/vendor/github.com/aws/amazon-ecs-agent/ecs-agent/api/resource/ebs_discovery_windows.go

@@ -16,6 +16,106 @@
 
 package resource
 
-func (api EBSDiscoveryClient) ConfirmEBSVolumeIsAttached(deviceName, volumeID string) error {
+import (
+	"context"
+	"fmt"
+	"os/exec"
+	"strings"
+
+	log "github.com/cihub/seelog"
+	"github.com/pkg/errors"
+)
+
+const (
+	diskNumberOffset = 0
+	volumeIdOffset   = 1
+	deviceNameOffset = 2
+	volumeInfoLength = 3
+)
+
+func (api *EBSDiscoveryClient) ConfirmEBSVolumeIsAttached(deviceName, volumeID string) error {
+	ctxWithTimeout, cancel := context.WithTimeout(api.ctx, ebsVolumeDiscoveryTimeout)
+	defer cancel()
+	output, err := exec.CommandContext(ctxWithTimeout,
+		"C:\\PROGRAMDATA\\Amazon\\Tools\\ebsnvme-id.exe").CombinedOutput()
+	if err != nil {
+		return errors.Wrapf(err, "failed to run ebsnvme-id.exe: %s", string(output))
+	}
+
+	_, err = parseExecutableOutput(output, volumeID, deviceName)
+	if err != nil {
+		return errors.Wrapf(err, "failed to parse ebsnvme-id.exe output for volumeID: %s and deviceName: %s",
+			volumeID, deviceName)
+	}
+
+	log.Info(fmt.Sprintf("found volume with volumeID: %s and deviceName: %s", volumeID, deviceName))
+
 	return nil
 }
+
+// parseExecutableOutput parses the output of `ebsnvme-id.exe` and returns the volumeId.
+func parseExecutableOutput(output []byte, candidateVolumeId string, candidateDeviceName string) (string, error) {
+	/* The output of the ebsnvme-id.exe is emitted like the following:
+	Disk Number: 0
+	Volume ID: vol-0a1234f340444abcd
+	Device Name: sda1
+
+	Disk Number: 1
+	Volume ID: vol-abcdef1234567890a
+	Device Name: /dev/sdf */
+
+	out := string(output)
+	// Replace double line with a single line and split based on single line
+	volumeInfo := strings.Split(strings.Replace(string(out), "\r\n\r\n", "\r\n", -1), "\r\n")
+
+	if len(volumeInfo) < volumeInfoLength {
+		return "", errors.New("cannot find the volume ID. Encountered error message: " + out)
+	}
+
+	//Read every 3 lines of disk information
+	for volumeIndex := 0; volumeIndex <= len(volumeInfo)-volumeInfoLength; volumeIndex = volumeIndex + volumeInfoLength {
+		_, volumeId, deviceName, err := parseSet(volumeInfo[volumeIndex : volumeIndex+volumeInfoLength])
+		if err != nil {
+			return "", errors.Wrapf(err, "failed to parse the output for volumeID: %s and deviceName: %s. "+
+				"Output:%s", candidateVolumeId, candidateDeviceName, out)
+		}
+
+		if volumeId == candidateVolumeId && deviceName == candidateDeviceName {
+			return volumeId, nil
+		}
+
+	}
+
+	return "", errors.New("cannot find the volume ID:" + candidateVolumeId)
+}
+
+// parseSet parses the single volume information that is 3 lines long
+func parseSet(lines []string) (string, string, string, error) {
+	if len(lines) != 3 {
+		return "", "", "", errors.New("the number of entries in the volume information is insufficient to parse. Expected 3 lines")
+	}
+
+	diskNumber, err := parseValue(lines[diskNumberOffset], "Disk Number:")
+	if err != nil {
+		return "", "", "", err
+	}
+	volumeId, err := parseValue(lines[volumeIdOffset], "Volume ID:")
+	if err != nil {
+		return "", "", "", err
+	}
+	deviceName, err := parseValue(lines[deviceNameOffset], "Device Name:")
+	if err != nil {
+		return "", "", "", err
+	}
+	return diskNumber, volumeId, deviceName, nil
+}
+
+// parseValue looks for the volume information identifier and replaces it to return just the value
+func parseValue(inputBuffer string, stringToTrim string) (string, error) {
+	// if the input buffer doesn't have the identifier for the information, return an error
+	if !strings.Contains(inputBuffer, stringToTrim) {
+		return "", errors.New("output buffer was missing the string:" + stringToTrim)
+	}
+
+	return strings.TrimSpace(strings.Replace(inputBuffer, stringToTrim, "", -1)), nil
+}