IPv6-only support for awslogs logging driver (#4577)

Author: amogh09

agent/config/ipcompatibility/ipcompatibility.go

@@ -24,11 +24,16 @@ func NewIPCompatibility(ipv4Compatible, ipv6Compatible bool) IPCompatibility {
 	return IPCompatibility{ipv4Compatible: ipv4Compatible, ipv6Compatible: ipv6Compatible}
 }
 
-// Returns an IPv4-only IPCompatibility instance.
+// Returns an IPv4-only IPCompatibility value.
 func NewIPv4OnlyCompatibility() IPCompatibility {
 	return NewIPCompatibility(true, false)
 }
 
+// Returns an IPv6-only IPCompatibility value.
+func NewIPv6OnlyCompatibility() IPCompatibility {
+	return NewIPCompatibility(false, true)
+}
+
 // IsIPv4Compatible returns the current IPv4 compatibility status.
 func (ic *IPCompatibility) IsIPv4Compatible() bool {
 	return ic.ipv4Compatible

agent/config/ipcompatibility/ipcompatibility_test.go

@@ -44,6 +44,12 @@ func TestIPv4OnlyCompatibility(t *testing.T) {
 	assert.False(t, c.IsIPv6Compatible())
 }
 
+func TestIPv6OnlyCompatibility(t *testing.T) {
+	c := NewIPv6OnlyCompatibility()
+	assert.True(t, c.IsIPv6Compatible())
+	assert.False(t, c.IsIPv4Compatible())
+}
+
 func TestIsIPv6Only(t *testing.T) {
 	tests := []struct {
 		name     string

agent/engine/docker_task_engine.go

@@ -56,8 +56,10 @@ import (
 	"github.com/aws/amazon-ecs-agent/ecs-agent/logger/field"
 	"github.com/aws/amazon-ecs-agent/ecs-agent/utils/retry"
 	"github.com/aws/amazon-ecs-agent/ecs-agent/utils/ttime"
+	"github.com/aws/aws-sdk-go-v2/service/cloudwatchlogs"
 	"github.com/aws/aws-sdk-go/aws"
 	ep "github.com/aws/aws-sdk-go/aws/endpoints"
+	"github.com/aws/smithy-go/ptr"
 	"github.com/docker/docker/api/types"
 	dockercontainer "github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/api/types/registry"
@@ -89,6 +91,8 @@ const (
 	logDriverTypeFirelens = "awsfirelens"
 	logDriverTypeFluentd  = "fluentd"
 	logDriverTypeAwslogs  = "awslogs"
+	awsLogsEndpointKey    = "awslogs-endpoint"
+	awsLogsRegionKey      = "awslogs-region"
 	logDriverTag          = "tag"
 	logDriverMode         = "mode"
 	logDriverBufferSize   = "max-buffer-size"
@@ -1945,29 +1949,33 @@ func (engine *DockerTaskEngine) createContainer(task *apitask.Task, container *a
 
 	// This is a short term solution only for specific regions
 	if hostConfig.LogConfig.Type == logDriverTypeAwslogs {
-		region := engine.cfg.AWSRegion
-		if _, ok := unresolvedIsolatedRegions[region]; ok {
-			endpoint := ""
-			dnsSuffix := ""
-			partition, ok := ep.PartitionForRegion(ep.DefaultPartitions(), region)
-			if !ok {
-				logger.Warn("No partition resolved for region. Using AWS default", logger.Fields{
-					"region":           region,
-					"defaultDNSSuffix": ep.AwsPartition().DNSSuffix(),
-				})
-				dnsSuffix = ep.AwsPartition().DNSSuffix()
-			} else {
-				resolvedEndpoint, err := partition.EndpointFor("logs", region)
-				if err == nil {
-					endpoint = resolvedEndpoint.URL
+		if engine.cfg.InstanceIPCompatibility.IsIPv6Only() {
+			engine.setAWSLogsDualStackEndpoint(task, container, hostConfig)
+		} else {
+			region := engine.cfg.AWSRegion
+			if _, ok := unresolvedIsolatedRegions[region]; ok {
+				endpoint := ""
+				dnsSuffix := ""
+				partition, ok := ep.PartitionForRegion(ep.DefaultPartitions(), region)
+				if !ok {
+					logger.Warn("No partition resolved for region. Using AWS default", logger.Fields{
+						"region":           region,
+						"defaultDNSSuffix": ep.AwsPartition().DNSSuffix(),
+					})
+					dnsSuffix = ep.AwsPartition().DNSSuffix()
 				} else {
-					dnsSuffix = partition.DNSSuffix()
+					resolvedEndpoint, err := partition.EndpointFor("logs", region)
+					if err == nil {
+						endpoint = resolvedEndpoint.URL
+					} else {
+						dnsSuffix = partition.DNSSuffix()
+					}
 				}
+				if endpoint == "" {
+					endpoint = fmt.Sprintf("https://logs.%s.%s", region, dnsSuffix)
+				}
+				hostConfig.LogConfig.Config[awsLogsEndpointKey] = endpoint
 			}
-			if endpoint == "" {
-				endpoint = fmt.Sprintf("https://logs.%s.%s", region, dnsSuffix)
-			}
-			hostConfig.LogConfig.Config["awslogs-endpoint"] = endpoint
 		}
 	}
 
@@ -2946,3 +2954,104 @@ func (engine *DockerTaskEngine) getDockerID(task *apitask.Task, container *apico
 	}
 	return dockerContainer.DockerID, nil
 }
+
+// Sets CloudWatch Logs dual stack endpoint as "awslogs-endpoint" option in the logging config.
+// This is needed because awslogs driver that we consume from Docker does not support
+// an option to enable dual stack endpoints, so customers have no way to enable dual stack endpoints
+// that are needed in an IPv6-only environment.
+func (engine *DockerTaskEngine) setAWSLogsDualStackEndpoint(
+	task *apitask.Task, container *apicontainer.Container, hostConfig *dockercontainer.HostConfig,
+) {
+	// Helper function to populate common logger.Fields
+	withAdditionalLoggerFields := func(additionalFields logger.Fields) logger.Fields {
+		fields := logger.Fields{field.TaskARN: task.Arn, field.ContainerName: container.Name}
+		for k, v := range additionalFields {
+			fields[k] = v
+		}
+		return fields
+	}
+
+	// Do nothing if endpoint is already set
+	if hostConfig.LogConfig.Config[awsLogsEndpointKey] != "" {
+		logger.Info(
+			fmt.Sprintf(
+				"%s is already set in awslogs config, skip resolving dual stack CloudWatch Logs endpoint",
+				awsLogsEndpointKey),
+			withAdditionalLoggerFields(logger.Fields{}),
+		)
+		return
+	}
+
+	// Region is required to resolve endpoint
+	region := hostConfig.LogConfig.Config[awsLogsRegionKey]
+	if region == "" {
+		logger.Warn(
+			fmt.Sprintf(
+				"%s not found in awslogs config, skip resolving dual stack CloudWatch Logs endpoint",
+				awsLogsRegionKey),
+			withAdditionalLoggerFields(logger.Fields{}),
+		)
+		return
+	}
+
+	// Docker versions older than 18.09.0 do not support awslogs-endpoint
+	// option. So, skip endpoint resolution for those Docker versions.
+	dockerVersion, err := engine.Version()
+	if err != nil {
+		logger.Error("Failed to get Docker engine version. Skip resolving dual stack CloudWatch Logs endpoint.",
+			withAdditionalLoggerFields(logger.Fields{field.Error: err}))
+		return
+	}
+	const thresholdVersion = "18.09.0"
+	dockerVersionIsCompatible, err := utils.Version(dockerVersion).Matches(">=" + thresholdVersion)
+	if err != nil {
+		logger.Error("Failed to determine if docker version is high enough",
+			withAdditionalLoggerFields(logger.Fields{
+				field.Error:         err,
+				field.DockerVersion: dockerVersion,
+				"thresholdVersion":  thresholdVersion,
+			}))
+		return
+	}
+	if !dockerVersionIsCompatible {
+		logger.Warn(
+			fmt.Sprintf(
+				"Docker version does not support %s option. Skip resolving dual stack CloudWatch Logs endpoint.",
+				awsLogsEndpointKey),
+			withAdditionalLoggerFields(logger.Fields{
+				field.DockerVersion: dockerVersion,
+				"thresholdVersion":  thresholdVersion,
+			}),
+		)
+		return
+	}
+
+	// Resolve the endpoint
+	endpoint, err := getAWSLogsDualStackEndpoint(region)
+	if err != nil {
+		logger.Error(
+			"Failed to get CloudWatch Logs dual stack endpoint. Skipping setting it.",
+			withAdditionalLoggerFields(logger.Fields{field.Region: region, field.Error: err}))
+		return
+	}
+
+	logger.Info("Resolved CloudWatch Logs dual stack endpoint",
+		withAdditionalLoggerFields(logger.Fields{
+			field.Endpoint: endpoint,
+			field.Region:   region,
+		}))
+	hostConfig.LogConfig.Config[awsLogsEndpointKey] = endpoint
+}
+
+// Returns CloudWatch Logs dual stack endpoint for the given region.
+func getAWSLogsDualStackEndpoint(region string) (string, error) {
+	endpoint, err := cloudwatchlogs.NewDefaultEndpointResolverV2().ResolveEndpoint(context.TODO(),
+		cloudwatchlogs.EndpointParameters{
+			UseDualStack: ptr.Bool(true),
+			Region:       ptr.String(region),
+		})
+	if err != nil {
+		return "", fmt.Errorf("failed to resolve dual stack CloudWatch Logs endpoint for region '%s': %w", region, err)
+	}
+	return endpoint.URI.String(), nil
+}