// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.

// SPDX-License-Identifier: Apache-2.0

package main

import (

"context"

"fmt"

"os"

"runtime/debug"

"github.com/jessevdk/go-flags"

"go.amzn.com/lambda/rapidcore"

log "github.com/sirupsen/logrus"

)

const (

optBootstrap = "/opt/bootstrap"

runtimeBootstrap = "/var/runtime/bootstrap"

)

type options struct {

LogLevel string `long:"log-level" default:"info" description:"log level"`

InitCachingEnabled bool `long:"enable-init-caching" description:"Enable support for Init Caching"`

}

func main() {

// More frequent GC reduces the tail latencies, equivalent to export GOGC=33

debug.SetGCPercent(33)

opts, args := getCLIArgs()

rapidcore.SetLogLevel(opts.LogLevel)

bootstrap, handler := getBootstrap(args, opts)

sandbox := rapidcore.

NewSandboxBuilder(bootstrap).

AddShutdownFunc(context.CancelFunc(func() { os.Exit(0) })).

SetExtensionsFlag(true).

SetInitCachingFlag(opts.InitCachingEnabled)

if len(handler) > 0 {

sandbox.SetHandler(handler)

}

go sandbox.Create()

testAPIipport := "0.0.0.0:8080"

startHTTPServer(testAPIipport, sandbox)

}

func getCLIArgs() (options, []string) {

var opts options

parser := flags.NewParser(&opts, flags.IgnoreUnknown)

args, err := parser.ParseArgs(os.Args)

if err != nil {

log.WithError(err).Fatal("Failed to parse command line arguments:", os.Args)

}

return opts, args

}

func isBootstrapFileExist(filePath string) bool {

file, err := os.Stat(filePath)

return !os.IsNotExist(err) && !file.IsDir()

}

func getBootstrap(args []string, opts options) (*rapidcore.Bootstrap, string) {

var bootstrapLookupCmd []string

var handler string

currentWorkingDir := "/var/task" // default value

if len(args) <= 1 {

// set default value to /var/task/bootstrap, but switch to the other options if it doesn't exist

bootstrapLookupCmd = []string{

fmt.Sprintf("%s/bootstrap", currentWorkingDir),

}

if !isBootstrapFileExist(bootstrapLookupCmd[0]) {

var bootstrapCmdCandidates = []string{

optBootstrap,

runtimeBootstrap,

}

for i, bootstrapCandidate := range bootstrapCmdCandidates {

if isBootstrapFileExist(bootstrapCandidate) {

bootstrapLookupCmd = []string{bootstrapCmdCandidates[i]}

break

}

}

}

// handler is used later to set an env var for Lambda Image support

handler = ""

} else if len(args) > 1 {

bootstrapLookupCmd = args[1:]

if cwd, err := os.Getwd(); err == nil {

currentWorkingDir = cwd

}

if len(args) > 2 {

// Assume last arg is the handler

handler = args[len(args)-1]

}

log.Infof("exec '%s' (cwd=%s, handler=%s)", args[1], currentWorkingDir, handler)

} else {

log.Panic("insufficient arguments: bootstrap not provided")

}

return rapidcore.NewBootstrapSingleCmd(bootstrapLookupCmd, currentWorkingDir), handler

}