Consume v4 container metadata handler from ecs-agent module (#3727)

agent/handlers/task_server_setup.go

@@ -29,9 +29,11 @@ import (
 	"github.com/aws/amazon-ecs-agent/agent/stats"
 	"github.com/aws/amazon-ecs-agent/ecs-agent/credentials"
 	auditinterface "github.com/aws/amazon-ecs-agent/ecs-agent/logger/audit"
+	"github.com/aws/amazon-ecs-agent/ecs-agent/metrics"
 	"github.com/aws/amazon-ecs-agent/ecs-agent/tmds"
 	tmdsv1 "github.com/aws/amazon-ecs-agent/ecs-agent/tmds/handlers/v1"
 	tmdsv2 "github.com/aws/amazon-ecs-agent/ecs-agent/tmds/handlers/v2"
+	tmdsv4 "github.com/aws/amazon-ecs-agent/ecs-agent/tmds/handlers/v4"
 	"github.com/aws/amazon-ecs-agent/ecs-agent/utils/retry"
 	"github.com/cihub/seelog"
 	"github.com/gorilla/mux"
@@ -135,8 +137,11 @@ func v4HandlersSetup(muxRouter *mux.Router,
 	cluster string,
 	availabilityZone string,
 	vpcID string,
-	containerInstanceArn string) {
-	muxRouter.HandleFunc(v4.ContainerMetadataPath, v4.ContainerMetadataHandler(state))
+	containerInstanceArn string,
+) {
+	tmdsAgentState := v4.NewTMDSAgentState(state)
+	metricsFactory := metrics.NewNopEntryFactory()
+	muxRouter.HandleFunc(tmdsv4.ContainerMetadataPath(), tmdsv4.ContainerMetadataHandler(tmdsAgentState, metricsFactory))
 	muxRouter.HandleFunc(v4.TaskMetadataPath, v4.TaskMetadataHandler(state, ecsClient, cluster, availabilityZone, vpcID, containerInstanceArn, false))
 	muxRouter.HandleFunc(v4.TaskWithTagsMetadataPath, v4.TaskMetadataHandler(state, ecsClient, cluster, availabilityZone, vpcID, containerInstanceArn, true))
 	muxRouter.HandleFunc(v4.ContainerStatsPath, v4.ContainerStatsHandler(state, statsEngine))

agent/handlers/v4/container_metadata_handler.go

@@ -14,72 +14,13 @@
 package v4
 
 import (
-	"encoding/json"
-	"fmt"
-	"net/http"
-
 	"github.com/aws/amazon-ecs-agent/agent/engine/dockerstate"
-	v3 "github.com/aws/amazon-ecs-agent/agent/handlers/v3"
 	tmdsresponse "github.com/aws/amazon-ecs-agent/ecs-agent/tmds/handlers/response"
-	"github.com/aws/amazon-ecs-agent/ecs-agent/tmds/handlers/utils"
 	tmdsv4 "github.com/aws/amazon-ecs-agent/ecs-agent/tmds/handlers/v4/state"
 
-	"github.com/cihub/seelog"
 	"github.com/pkg/errors"
 )
 
-// ContainerMetadataPath specifies the relative URI path for serving container metadata.
-var ContainerMetadataPath = "/v4/" + utils.ConstructMuxVar(v3.V3EndpointIDMuxName, utils.AnythingButSlashRegEx)
-
-// ContainerMetadataHandler returns the handler method for handling container metadata requests.
-func ContainerMetadataHandler(state dockerstate.TaskEngineState) func(http.ResponseWriter, *http.Request) {
-	return func(w http.ResponseWriter, r *http.Request) {
-		containerID, err := v3.GetContainerIDByRequest(r, state)
-		if err != nil {
-			responseJSON, err := json.Marshal(
-				fmt.Sprintf("V4 container metadata handler: unable to get container ID from request: %s", err.Error()))
-			if e := utils.WriteResponseIfMarshalError(w, err); e != nil {
-				return
-			}
-			utils.WriteJSONToResponse(w, http.StatusNotFound, responseJSON, utils.RequestTypeContainerMetadata)
-			return
-		}
-		containerResponse, err := GetContainerResponse(containerID, state)
-		if err != nil {
-			errResponseJSON, err := json.Marshal(err.Error())
-			if e := utils.WriteResponseIfMarshalError(w, err); e != nil {
-				return
-			}
-			utils.WriteJSONToResponse(w, http.StatusInternalServerError, errResponseJSON, utils.RequestTypeContainerMetadata)
-			return
-		}
-		seelog.Infof("V4 container metadata handler: writing response for container '%s'", containerID)
-
-		responseJSON, err := json.Marshal(containerResponse)
-		if e := utils.WriteResponseIfMarshalError(w, err); e != nil {
-			return
-		}
-		utils.WriteJSONToResponse(w, http.StatusOK, responseJSON, utils.RequestTypeContainerMetadata)
-	}
-}
-
-// GetContainerResponse gets container response for v4 metadata
-func GetContainerResponse(containerID string, state dockerstate.TaskEngineState) (*tmdsv4.ContainerResponse, error) {
-	containerResponse, err := NewContainerResponse(containerID, state)
-	if err != nil {
-		seelog.Errorf("Unable to get container metadata for container '%s'", containerID)
-		return nil, errors.Errorf("unable to generate metadata for container '%s'", containerID)
-	}
-
-	// fill in network details if not set for NON AWSVPC Task
-	if containerResponse.Networks == nil {
-		if containerResponse.Networks, err = GetContainerNetworkMetadata(containerID, state); err != nil {
-			return nil, err
-		}
-	}
-	return containerResponse, nil
-}
-
 // GetContainerNetworkMetadata returns the network metadata for the container
 func GetContainerNetworkMetadata(containerID string, state dockerstate.TaskEngineState) ([]tmdsv4.Network, error) {
 	dockerContainer, ok := state.ContainerByID(containerID)

agent/handlers/v4/tmdsstate.go

@@ -0,0 +1,59 @@
+// Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//	http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file 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 v4
+
+import (
+	"fmt"
+
+	"github.com/aws/amazon-ecs-agent/agent/engine/dockerstate"
+	tmdsv4 "github.com/aws/amazon-ecs-agent/ecs-agent/tmds/handlers/v4/state"
+
+	"github.com/cihub/seelog"
+)
+
+// Implements AgentState interface for TMDS v4.
+type TMDSAgentState struct {
+	state dockerstate.TaskEngineState
+}
+
+func NewTMDSAgentState(state dockerstate.TaskEngineState) *TMDSAgentState {
+	return &TMDSAgentState{state: state}
+}
+
+// Returns container metadata in v4 format for the container identified by the provided
+// v3EndpointID.
+func (s *TMDSAgentState) GetContainerMetadata(v3EndpointID string) (tmdsv4.ContainerResponse, error) {
+	// Get docker ID from the v3 endpoint ID.
+	containerID, ok := s.state.DockerIDByV3EndpointID(v3EndpointID)
+	if !ok {
+		return tmdsv4.ContainerResponse{}, tmdsv4.NewErrorLookupFailure(fmt.Sprintf(
+			"unable to get container ID from request: unable to get docker ID from v3 endpoint ID: %s",
+			v3EndpointID))
+	}
+
+	containerResponse, err := NewContainerResponse(containerID, s.state)
+	if err != nil {
+		seelog.Errorf("Unable to get container metadata for container '%s'", containerID)
+		return tmdsv4.ContainerResponse{}, tmdsv4.NewErrorMetadataFetchFailure(fmt.Sprintf(
+			"unable to generate metadata for container '%s'", containerID))
+	}
+
+	// fill in network details if not set for NON AWSVPC Task
+	if containerResponse.Networks == nil {
+		if containerResponse.Networks, err = GetContainerNetworkMetadata(containerID, s.state); err != nil {
+			return tmdsv4.ContainerResponse{}, tmdsv4.NewErrorMetadataFetchFailure(err.Error())
+		}
+	}
+
+	return *containerResponse, nil
+}