init commit

.editorconfig

@@ -0,0 +1,28 @@
+# EditorConfig is awesome: https://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[**/*.md]
+trim_trailing_whitespace = false
+
+[**/*.go]
+indent_size = 4
+
+[Makefile]
+indent_style = tab
+indent_size = 4
+
+[Dockerfile]
+indent_size = 4
+
+[VERSION]
+insert_final_newline = false

.gitignore

@@ -0,0 +1 @@
+build

.vscode/launch.json

@@ -0,0 +1,22 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+      {
+        "name": "main",
+        "type": "go",
+        "request": "launch",
+        "mode": "auto",
+        "program": "${workspaceFolder}/main.go"
+    },
+        {
+            "name": "Test",
+            "type": "go",
+            "request": "launch",
+            "mode": "test",
+            "program": "${fileDirname}"
+        }
+    ]
+}

go.mod

@@ -0,0 +1,11 @@
+module github.com/nthienan/aws-dynamodb-cache-lambda-extension
+
+go 1.19
+
+require (
+	github.com/aws/aws-sdk-go v1.44.239
+	github.com/gorilla/mux v1.8.0
+	gopkg.in/yaml.v2 v2.4.0
+)
+
+require github.com/jmespath/go-jmespath v0.4.0 // indirect

go.sum

@@ -0,0 +1,46 @@
+github.com/aws/aws-sdk-go v1.44.239 h1:AenB6byCYGSBb30q99CGYqFbqpLpWrTidzm7MzxtuPo=
+github.com/aws/aws-sdk-go v1.44.239/go.mod h1:aVsgQcEevwlmQ7qHE9I3h+dtQgpqhFB+i8Phjh7fkwI=
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/gorilla/mux v1.8.0 h1:i40aqfkR1h2SlN9hojwV5ZA91wcXFOvkdNIeFDP5koI=
+github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
+github.com/jmespath/go-jmespath v0.4.0 h1:BEgLn5cpjn8UN1mAw4NjwDrS35OdebyEtFe+9YPoQUg=
+github.com/jmespath/go-jmespath v0.4.0/go.mod h1:T8mJZnbsbmF+m6zOOFylbeCJqk5+pHWvzYPziyZiYoo=
+github.com/jmespath/go-jmespath/internal/testify v1.5.1 h1:shLQSRRSCCPj3f2gpwzGwWFoC7ycTf1rcQZHOlsJ6N8=
+github.com/jmespath/go-jmespath/internal/testify v1.5.1/go.mod h1:L3OGu8Wl2/fWfCI6z80xFu9LTZmf1ZRjMHUOPmWr69U=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
+golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
+golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
+golang.org/x/net v0.1.0/go.mod h1:Cx3nUiGt4eDBEyega/BKRp+/AlGL8hYe7U9odMt2Cco=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
+golang.org/x/term v0.1.0/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
+golang.org/x/text v0.4.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
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+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=

internal/extension/client.go

@@ -0,0 +1,129 @@
+package extension
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+)
+
+// RegisterResponse is the body of the response for /register
+type RegisterResponse struct {
+	FunctionName    string `json:"functionName"`
+	FunctionVersion string `json:"functionVersion"`
+	Handler         string `json:"handler"`
+}
+
+// NextEventResponse is the response for /event/next
+type NextEventResponse struct {
+	EventType          EventType `json:"eventType"`
+	DeadlineMs         int64     `json:"deadlineMs"`
+	RequestID          string    `json:"requestId"`
+	InvokedFunctionArn string    `json:"invokedFunctionArn"`
+	Tracing            Tracing   `json:"tracing"`
+}
+
+// Tracing is part of the response for /event/next
+type Tracing struct {
+	Type  string `json:"type"`
+	Value string `json:"value"`
+}
+
+// EventType represents the type of events recieved from /event/next
+type EventType string
+
+const (
+	// Invoke is a lambda invoke
+	Invoke EventType = "INVOKE"
+
+	// Shutdown is a shutdown event for the environment
+	Shutdown EventType = "SHUTDOWN"
+
+	extensionNameHeader      = "Lambda-Extension-Name"
+	extensionIdentiferHeader = "Lambda-Extension-Identifier"
+)
+
+// Client is a simple client for the Lambda Extensions API
+type Client struct {
+	baseURL     string
+	httpClient  *http.Client
+	extensionID string
+}
+
+// NewClient returns a Lambda Extensions API client
+func NewClient(awsLambdaRuntimeAPI string) *Client {
+	baseURL := fmt.Sprintf("http://%s/2020-01-01/extension", awsLambdaRuntimeAPI)
+	return &Client{
+		baseURL:    baseURL,
+		httpClient: &http.Client{},
+	}
+}
+
+// Register will register the extension with the Extensions API
+func (e *Client) Register(ctx context.Context, filename string) (*RegisterResponse, error) {
+	const action = "/register"
+	url := e.baseURL + action
+
+	reqBody, err := json.Marshal(map[string]interface{}{
+		"events": []EventType{Invoke, Shutdown},
+	})
+	if err != nil {
+		return nil, err
+	}
+	httpReq, err := http.NewRequestWithContext(ctx, "POST", url, bytes.NewBuffer(reqBody))
+	if err != nil {
+		return nil, err
+	}
+	httpReq.Header.Set(extensionNameHeader, filename)
+	httpRes, err := e.httpClient.Do(httpReq)
+	if err != nil {
+		return nil, err
+	}
+	if httpRes.StatusCode != 200 {
+		return nil, fmt.Errorf("request failed with status %s", httpRes.Status)
+	}
+	defer httpRes.Body.Close()
+	body, err := io.ReadAll(httpRes.Body)
+	if err != nil {
+		return nil, err
+	}
+	res := RegisterResponse{}
+	err = json.Unmarshal(body, &res)
+	if err != nil {
+		return nil, err
+	}
+	e.extensionID = httpRes.Header.Get(extensionIdentiferHeader)
+	return &res, nil
+}
+
+// NextEvent blocks while long polling for the next lambda invoke or shutdown
+func (e *Client) NextEvent(ctx context.Context) (*NextEventResponse, error) {
+	const action = "/event/next"
+	url := e.baseURL + action
+
+	httpReq, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	if err != nil {
+		return nil, err
+	}
+	httpReq.Header.Set(extensionIdentiferHeader, e.extensionID)
+	httpRes, err := e.httpClient.Do(httpReq)
+	if err != nil {
+		return nil, err
+	}
+	if httpRes.StatusCode != 200 {
+		return nil, fmt.Errorf("request failed with status %s", httpRes.Status)
+	}
+	defer httpRes.Body.Close()
+	body, err := io.ReadAll(httpRes.Body)
+	if err != nil {
+		return nil, err
+	}
+	res := NextEventResponse{}
+	err = json.Unmarshal(body, &res)
+	if err != nil {
+		return nil, err
+	}
+	return &res, nil
+}

internal/extension/entry.go

@@ -0,0 +1,82 @@
+package extension
+
+import (
+	"log"
+	"os"
+	"strconv"
+
+	"github.com/nthienan/aws-dynamodb-cache-lambda-extension/internal/plugins"
+	"gopkg.in/yaml.v2"
+)
+
+// Constants definition
+const (
+	Parameters = "parameters"
+	Dynamodb   = "dynamodb"
+	FileName                 = "/var/task/config.yaml"
+	InitializeCacheOnStartup = "CACHE_EXTENSION_INIT_STARTUP"
+)
+
+// Struct for storing CacheConfiguration
+type CacheConfig struct {
+	DynamoDb []plugins.DynamoDbConfiguration
+}
+
+var cacheConfig = CacheConfig{}
+
+// Initialize cache and start the background process to refresh cache
+func InitCacheExtensions() {
+	// Read the cache config file
+	data := LoadConfigFile()
+
+	// Unmarshal the configuration to struct
+	err := yaml.Unmarshal([]byte(data), &cacheConfig)
+	if err != nil {
+		log.Fatalf(plugins.PrintPrefix, "error: %v", err)
+	}
+
+	// Initialize Cache
+	println(plugins.PrintPrefix, "Initializing cache ...")
+	InitCache()
+	println(plugins.PrintPrefix, "Cache successfully loaded")
+}
+
+// Initialize individual cache
+func InitCache() {
+
+	// Read Lambda env variable
+	var initCache = os.Getenv(InitializeCacheOnStartup)
+	var initCacheInBool = false
+	if initCache != "" {
+		cacheInBool, err := strconv.ParseBool(initCache)
+		if err != nil {
+			panic(plugins.PrintPrefix + "Error while converting CACHE_EXTENSION_INIT_STARTUP env variable " +
+				initCache)
+		} else {
+			initCacheInBool = cacheInBool
+		}
+	}
+
+	// Initialize map and load data from individual services if "CACHE_EXTENSION_INIT_STARTUP" = true
+	plugins.InitDynamodb(cacheConfig.DynamoDb, initCacheInBool)
+}
+
+// Route request to corresponding cache handlers
+func RouteCache(cacheType string, name string) string {
+	switch cacheType {
+	case Dynamodb:
+		return plugins.FetchDynamoDbCache(name)
+	default:
+		return ""
+	}
+}
+
+// Load the config file
+func LoadConfigFile() string {
+	data, err := os.ReadFile(FileName)
+	if err != nil {
+		panic(err)
+	}
+
+	return string(data)
+}

internal/ipc/ipc.go

@@ -0,0 +1,35 @@
+package ipc
+
+import (
+	"github.com/nthienan/aws-dynamodb-cache-lambda-extension/internal/extension"
+	"github.com/nthienan/aws-dynamodb-cache-lambda-extension/internal/plugins"
+	"github.com/gorilla/mux"
+	"net/http"
+)
+
+// Start begins running the sidecar
+func Start(port string) {
+	go startHTTPServer(port)
+}
+
+// Method that responds back with the cached values
+func startHTTPServer(port string) {
+	router := mux.NewRouter()
+	router.Path("/{cacheType}").Queries("name", "{name}").HandlerFunc(
+		func(w http.ResponseWriter, r *http.Request) {
+			vars := mux.Vars(r)
+			value := extension.RouteCache(vars["cacheType"], vars["name"])
+
+			if len(value) != 0 {
+				_, _ = w.Write([]byte(value))
+			} else {
+				_, _ = w.Write([]byte("No data found"))
+			}
+		})
+
+	println(plugins.PrintPrefix, "Starting Httpserver on port ", port)
+	err := http.ListenAndServe(":"+port, router)
+	if err != nil {
+		panic(err)
+	}
+}