user-data Support

pkg/cmd/cmdutil/cmdutil.go

@@ -26,6 +26,7 @@ import (
 	"github.com/aws/amazon-ec2-metadata-mock/pkg/mock/imdsv2"
 	"github.com/aws/amazon-ec2-metadata-mock/pkg/mock/spot"
 	"github.com/aws/amazon-ec2-metadata-mock/pkg/mock/static"
+	"github.com/aws/amazon-ec2-metadata-mock/pkg/mock/userdata"
 	"github.com/aws/amazon-ec2-metadata-mock/pkg/server"
 
 	"github.com/spf13/cobra"
@@ -91,6 +92,7 @@ func RegisterHandlers(cmd *cobra.Command, config cfg.Config) {
 
 	static.RegisterHandlers(config)
 	dynamic.RegisterHandlers(config)
+	userdata.RegisterHandlers(config)
 
 	// paths without explicit handler bindings will fallback to CatchAllHandler
 	server.HandleFuncPrefix("/", handlers.CatchAllHandler)

pkg/config/config.go

@@ -119,6 +119,7 @@ func LoadConfigForRoot(configFileFlagName string, cmdDefaults map[string]interfa
 	LoadConfigFromDefaults(cmdDefaults)
 	SetMetadataDefaults(defaults.GetDefaultValues())
 	SetDynamicDefaults(defaults.GetDefaultValues())
+	SetUserdataDefaults(defaults.GetDefaultValues())
 	SetServerCfgDefaults()
 
 	// read in config using viper

pkg/config/defaults/aemm-metadata-default-values.json

@@ -175,5 +175,13 @@
       "instance-identity-signature": "TesTTKmBbj+DUw6ut6BOr4mFGpax/k6BhIbsotUHvSIhqv7oKqwB4HZhgGP2Gvcxtz5m3QGUbnwI\nhy33GWxjn7+qfZ/GUeZB1Ilc+3rW/P9G/tGxIB3HtqB6q2J6B4DOh6CJiH+BnrHazGW+bJD406Nz\neP9n/rGEGGm0cGEbbeB=",
       "fws-instance-monitoring": "disabled"
     }
+  },
+  "userdata": {
+    "paths": {
+      "userdata": "/latest/user-data"
+    },
+    "values": {
+      "userdata": "1234,john,reboot,true|4512,richard,|173,,,"
+    }
   }
 }

pkg/config/defaults/defaults.go

@@ -1,4 +1,4 @@
-// Copyright 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// 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

pkg/config/types.go

@@ -24,6 +24,8 @@ import (
 type Config struct {
 	// ----- metadata config ----- //
 	Metadata Metadata `mapstructure:"metadata"`
+	// ----- userdata config ----- //
+	Userdata Userdata `mapstructure:"userdata"`
 
 	// ----- CLI config ----- //
 	// config keys that are also cli flags
@@ -57,6 +59,12 @@ type Metadata struct {
 	Values Values `mapstructure:"values"`
 }
 
+// Userdata represents userdata config used by the mock (Json values in metadata-config.json)
+type Userdata struct {
+	Paths  UserdataPaths  `mapstructure:"paths"`
+	Values UserdataValues `mapstructure:"values"`
+}
+
 // Dynamic represents metadata config used by the mock (Json values in metadata-config.json)
 type Dynamic struct {
 	Paths  DynamicPaths  `mapstructure:"paths"`
@@ -194,6 +202,16 @@ type Values struct {
 	TagsInstanceTest             string                            `mapstructure:"tags-instance-test"`
 }
 
+// UserdataPaths represents EC2 userdata paths
+type UserdataPaths struct {
+	Userdata string `mapstructure:"userdata"`
+}
+
+// UserdataValues represents EC2 userdata paths
+type UserdataValues struct {
+	Userdata string `mapstructure:"userdata"`
+}
+
 // DynamicPaths represents EC2 dynamic paths
 type DynamicPaths struct {
 	InstanceIdentityDocument  string `mapstructure:"instance-identity-document"`

pkg/config/userdata.go

@@ -0,0 +1,85 @@
+// 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 config
+
+import (
+	"encoding/json"
+
+	"github.com/spf13/pflag"
+)
+
+var (
+	udCfgPrefix       = "userdata."
+	udPathsCfgPrefix  = udCfgPrefix + "paths."
+	udValuesCfgPrefix = udCfgPrefix + "values."
+
+	// mapping of udValue KEYS to udPath KEYS requiring path substitutions on override
+	udValueToPlaceholderPathsKeyMap = map[string][]string{}
+
+	// supported URL paths to run a mock
+	udPathsDefaults = map[string]interface{}{}
+
+	// values in mock responses
+	udValuesDefaults = map[string]interface{}{}
+)
+
+// GetCfgUdValPrefix returns the prefix to use to access userdata values in config
+func GetCfgUdValPrefix() string {
+	return udCfgPrefix + "." + udValuesCfgPrefix + "."
+}
+
+// GetCfgUdPathsPrefix returns the prefix to use to access userdata values in config
+func GetCfgUdPathsPrefix() string {
+	return udCfgPrefix + "." + udPathsCfgPrefix + "."
+}
+
+// BindUserdataCfg binds a flag that represents a userdata value to configuration
+func BindUserdataCfg(flag *pflag.Flag) {
+	bindFlagWithKeyPrefix(flag, udValuesCfgPrefix)
+}
+
+// SetUserdataDefaults sets config defaults for userdata paths and values
+func SetUserdataDefaults(jsonWithDefaults []byte) {
+	// Unmarshal to map to preserve keys for Paths and Values
+	var defaultsMap map[string]interface{}
+	json.Unmarshal(jsonWithDefaults, &defaultsMap)
+	udPaths := defaultsMap["userdata"].(map[string]interface{})["paths"].(map[string]interface{})
+
+	udValues := defaultsMap["userdata"].(map[string]interface{})["values"].(map[string]interface{})
+
+	for k, v := range udPaths {
+		newKey := udPathsCfgPrefix + k
+		// ex: "userdata": "/latest/user-data"
+		udPathsDefaults[newKey] = v
+	}
+
+	for k, v := range udValues {
+		newKey := udValuesCfgPrefix + k
+		// ex: "userdata": "1234,john,reboot,true|4512,richard,|173,,,"
+		udValuesDefaults[newKey] = v
+	}
+
+	LoadConfigFromDefaults(udPathsDefaults)
+	LoadConfigFromDefaults(udValuesDefaults)
+}
+
+// GetUserdataDefaults returns config defaults for userdata paths and values
+func GetUserdataDefaults() (map[string]interface{}, map[string]interface{}) {
+	return udPathsDefaults, udValuesDefaults
+}
+
+// GetUserdataValueToPlaceholderPathsKeyMap returns collection of userdata values that are substituted into paths
+func GetUserdataValueToPlaceholderPathsKeyMap() map[string][]string {
+	return udValueToPlaceholderPathsKeyMap
+}

pkg/mock/handlers/handlers.go

@@ -21,6 +21,7 @@ import (
 
 	"github.com/aws/amazon-ec2-metadata-mock/pkg/mock/dynamic"
 	"github.com/aws/amazon-ec2-metadata-mock/pkg/mock/static"
+	"github.com/aws/amazon-ec2-metadata-mock/pkg/mock/userdata"
 	"github.com/aws/amazon-ec2-metadata-mock/pkg/server"
 )
 
@@ -35,11 +36,12 @@ var (
 	routeLookupTable = make(map[string][]string)
 
 	supportedVersions   = []string{"latest"}
-	supportedCategories = []string{"dynamic", "meta-data"}
+	supportedCategories = []string{"dynamic", "meta-data", "user-data"}
 
 	// trimmedRoutes represents the list of routes served by the http server without "latest/meta-data/" prefix
-	trimmedRoutes        []string
-	trimmedRoutesDynamic []string
+	trimmedRoutes         []string
+	trimmedRoutesDynamic  []string
+	trimmedRoutesUserdata []string
 )
 
 // CatchAllHandler returns subpath listings, if available; 404 status code otherwise
@@ -62,6 +64,10 @@ func CatchAllHandler(res http.ResponseWriter, req *http.Request) {
 		trimmedRoute = strings.TrimPrefix(trimmedRoute, dynamic.ServicePath+"/")
 		log.Println("dynamic prefix detected..trimming: ", trimmedRoute)
 		routes = trimmedRoutesDynamic
+	} else if strings.HasPrefix(trimmedRoute, userdata.ServicePath) {
+		trimmedRoute = strings.TrimPrefix(trimmedRoute, userdata.ServicePath+"/")
+		log.Println("userdata prefix detected..trimming: ", trimmedRoute)
+		routes = trimmedRoutesUserdata
 	} else {
 		server.ReturnNotFoundResponse(res)
 		return
@@ -124,6 +130,8 @@ func ListRoutesHandler(res http.ResponseWriter, req *http.Request) {
 
 	// these paths do not use routeLookupTable due to inconsistency of trailing "/" with IMDS
 	switch req.URL.Path {
+	case userdata.ServicePath:
+		server.FormatAndReturnOctetResponse(res, strings.Join(trimmedRoutesUserdata, "\n")+"\n")
 	case static.ServicePath:
 		server.FormatAndReturnTextResponse(res, strings.Join(trimmedRoutes, "\n")+"\n")
 	case dynamic.ServicePath:
@@ -142,15 +150,24 @@ func formatRoutes() {
 	var trimmedRoute string
 	for _, route := range server.Routes {
 		if strings.HasPrefix(route, dynamic.ServicePath) {
-			// Omit /latest/dynamic
+			// Omit /latest/dynamic and /latest/user-data
 			trimmedRoute = strings.TrimPrefix(route, dynamic.ServicePath)
 			// Omit empty paths and "/"
 			if len(trimmedRoute) >= shortestRouteLength {
 				trimmedRoute = strings.TrimPrefix(trimmedRoute, "/")
 				trimmedRoutesDynamic = append(trimmedRoutesDynamic, trimmedRoute)
 			}
+		} else if strings.HasPrefix(route, userdata.ServicePath) {
+			// Omit /latest/dynamic and /latest/meta-data
+			trimmedRoute = strings.TrimPrefix(route, userdata.ServicePath)
+			// Omit empty paths and "/"
+			if len(trimmedRoute) >= shortestRouteLength {
+				trimmedRoute = strings.TrimPrefix(trimmedRoute, "/")
+				trimmedRoutesUserdata = append(trimmedRoutesUserdata, trimmedRoute)
+			}
+
 		} else {
-			// Omit /latest/meta-data
+			// Omit /latest/meta-data and /latest/user-data
 			trimmedRoute = strings.TrimPrefix(route, static.ServicePath)
 			// Omit empty paths and "/"
 			if len(trimmedRoute) >= shortestRouteLength {
@@ -161,4 +178,5 @@ func formatRoutes() {
 	}
 	sort.Sort(sort.StringSlice(trimmedRoutes))
 	sort.Sort(sort.StringSlice(trimmedRoutesDynamic))
+	sort.Sort(sort.StringSlice(trimmedRoutesUserdata))
 }

pkg/mock/userdata/userdata.go

@@ -0,0 +1,74 @@
+// 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 userdata
+
+import (
+	"log"
+	"net/http"
+	"reflect"
+
+	cfg "github.com/aws/amazon-ec2-metadata-mock/pkg/config"
+	"github.com/aws/amazon-ec2-metadata-mock/pkg/mock/imdsv2"
+	"github.com/aws/amazon-ec2-metadata-mock/pkg/server"
+)
+
+var (
+	supportedPaths = make(map[string]interface{})
+	response       interface{}
+	// ServicePath defines the userdata service path
+	ServicePath = "/latest/user-data"
+)
+
+// Handler processes http requests
+func Handler(res http.ResponseWriter, req *http.Request) {
+	log.Println("Received request to mock userdata:", req.URL.Path)
+
+	if val, ok := supportedPaths[req.URL.Path]; ok {
+
+		response = val
+	} else {
+		response = "Something went wrong with: " + req.URL.Path
+	}
+	server.FormatAndReturnOctetResponse(res, response.(string))
+
+}
+
+// RegisterHandlers registers handlers for userdata paths
+func RegisterHandlers(config cfg.Config) {
+	pathValues := reflect.ValueOf(config.Userdata.Paths)
+	udValues := reflect.ValueOf(config.Userdata.Values)
+	// Iterate over fields in config.Userdata.Paths to
+	// determine intersections with config.Userdata.Values.
+	// Intersections represent which paths and values to bind.
+	for i := 0; i < pathValues.NumField(); i++ {
+		pathFieldName := pathValues.Type().Field(i).Name
+		udValueFieldName := udValues.FieldByName(pathFieldName)
+		if udValueFieldName.IsValid() {
+			path := pathValues.Field(i).Interface().(string)
+			value := udValueFieldName.Interface()
+			if path != "" && value != nil {
+				// Ex: "/latest/meta-data/instance-id" : "i-1234567890abcdef0"
+				supportedPaths[path] = value
+				if config.Imdsv2Required {
+					server.HandleFunc(path, imdsv2.ValidateToken(Handler))
+				} else {
+
+					server.HandleFunc(path, Handler)
+				}
+			} else {
+				log.Printf("There was an issue registering path %v with udValue: %v", path, value)
+			}
+		}
+	}
+}

pkg/server/httpserver.go

@@ -120,6 +120,14 @@ func FormatAndReturnTextResponse(res http.ResponseWriter, data string) {
 	return
 }
 
+// FormatAndReturnOctetResponse formats the given data into an octet stream and returns the response
+func FormatAndReturnOctetResponse(res http.ResponseWriter, data string) {
+	res.Header().Set("Content-Type", "application/octet-stream")
+	res.Write([]byte(data))
+	log.Println("Returned octet stream response successfully.")
+	return
+}
+
 // FormatAndReturnJSONTextResponse formats the given data into JSON and returns a plaintext response
 func FormatAndReturnJSONTextResponse(res http.ResponseWriter, data interface{}) {
 	res.Header().Set("Content-Type", "text/plain")

test/e2e/cmd/userdata-test

@@ -0,0 +1,59 @@
+#! /usr/bin/env bash
+
+set -euo pipefail
+
+TEST_CONFIG_FILE="$SCRIPTPATH/testdata/aemm-config-integ.json"
+
+USERDATA_DEFAULT="1234,john,reboot,true|4512,richard,|173,,,"
+USERDATA_OVERRIDDEN="1234"
+
+ROOT_PATH="http://$HOSTNAME:$AEMM_PORT"
+USERDATA_TEST_PATH="$ROOT_PATH/latest/user-data"
+
+function test_userdata_defaults() {
+  pid=$1
+  test_url=$2
+  test_name=$3
+  tput setaf $BLUE
+  health_check $test_url
+  TOKEN=$(get_v2Token $MAX_TOKEN_TTL $AEMM_PORT)
+
+  actual_userdata=$(curl -s -H "X-aws-ec2-metadata-token: $TOKEN" $USERDATA_TEST_PATH)
+  assert_value "$actual_userdata" $USERDATA_DEFAULT "userdata $test_name"
+
+  clean_up $pid
+}
+
+function test_userdata_overrides() {
+  pid=$1
+  test_url=$2
+  test_name=$3
+  tput setaf $BLUE
+  health_check $test_url
+  TOKEN=$(get_v2Token $MAX_TOKEN_TTL $AEMM_PORT)
+
+  updated_userdata=$(curl -s -H "X-aws-ec2-metadata-token: $TOKEN" $USERDATA_TEST_PATH)
+  assert_value "$updated_userdata" $USERDATA_OVERRIDDEN "userdata $test_name"
+
+  clean_up $pid
+}
+
+tput setaf $BLUE
+echo "======================================================================================================"
+echo "🥑 Starting userdata integration tests $METADATA_VERSION"
+echo "======================================================================================================"
+
+
+# userdata data defaults
+start_cmd=$(create_cmd $METADATA_VERSION --port $AEMM_PORT)
+$start_cmd &
+USERDATA_PID=$!
+test_userdata_defaults $USERDATA_PID $USERDATA_TEST_PATH $USERDATA_DEFAULT
+
+# userdata data overrides
+start_cmd=$(create_cmd $METADATA_VERSION --port $AEMM_PORT -c $TEST_CONFIG_FILE)
+$start_cmd &
+USERDATA_PID=$!
+test_userdata_overrides $USERDATA_PID $USERDATA_TEST_PATH $USERDATA_OVERRIDDEN
+
+exit $EXIT_CODE_TO_RETURN