Allow LocalStack specific configuration of chmod on startup, remove D…

…NS logic (#34)

cmd/localstack/awsutil.go

@@ -139,23 +139,6 @@ func resetListener(changeChannel <-chan bool, server *CustomInteropServer) {
 
 }
 
-func RunDNSRewriter(opts *LsOpts, ctx context.Context) {
-	if opts.EnableDnsServer != "1" {
-		log.Debugln("DNS server disabled.")
-		return
-	}
-	dnsForwarder, err := NewDnsForwarder(opts.LocalstackIP)
-	if err != nil {
-		log.Errorln("Error creating dns forwarder.")
-		return
-	}
-	defer dnsForwarder.Shutdown()
-	dnsForwarder.Start()
-
-	<-ctx.Done()
-	log.Debugln("DNS server stopped")
-}
-
 func RunHotReloadingListener(server *CustomInteropServer, targetPaths []string, ctx context.Context, fileWatcherStrategy string) {
 	if len(targetPaths) == 1 && targetPaths[0] == "" {
 		log.Debugln("Hot reloading disabled.")

cmd/localstack/file_utils.go

@@ -1,11 +1,40 @@
 package main
 
 import (
+	"encoding/json"
+	log "github.com/sirupsen/logrus"
 	"io"
 	"os"
 	"path/filepath"
+	"strconv"
 )
 
+type Chmod struct {
+	Path string `json:"path"`
+	Mode string `json:"mode"`
+}
+
+// AdaptFilesystemPermissions Adapts the file system permissions to the mode specified in the chmodInfoString parameter
+// chmodInfoString should be a json encoded list of `Chmod` structs.
+// example: '[{"path": "/opt", "mode": "0755"}]'. The mode string should be an octal representation of the targeted file mode.
+func AdaptFilesystemPermissions(chmodInfoString string) error {
+	var chmodInfo []Chmod
+	err := json.Unmarshal([]byte(chmodInfoString), &chmodInfo)
+	if err != nil {
+		return err
+	}
+	for _, chmod := range chmodInfo {
+		mode, err := strconv.ParseInt(chmod.Mode, 0, 32)
+		if err != nil {
+			return err
+		}
+		if err := ChmodRecursively(chmod.Path, os.FileMode(mode)); err != nil {
+			log.Warnf("Could not change file mode recursively of directory %s: %s\n", chmod.Path, err)
+		}
+	}
+	return nil
+}
+
 // Inspired by https://stackoverflow.com/questions/73864379/golang-change-permission-os-chmod-and-os-chowm-recursively
 // but using the more efficient WalkDir API
 func ChmodRecursively(root string, mode os.FileMode) error {

cmd/localstack/main.go

@@ -23,7 +23,7 @@ type LsOpts struct {
 	CodeArchives        string
 	HotReloadingPaths   []string
 	FileWatcherStrategy string
-	EnableDnsServer     string
+	ChmodPaths          string
 	LocalstackIP        string
 	InitLogLevel        string
 	EdgePort            string
@@ -57,10 +57,10 @@ func InitLsOpts() *LsOpts {
 		CodeArchives:        os.Getenv("LOCALSTACK_CODE_ARCHIVES"),
 		HotReloadingPaths:   strings.Split(GetenvWithDefault("LOCALSTACK_HOT_RELOADING_PATHS", ""), ","),
 		FileWatcherStrategy: os.Getenv("LOCALSTACK_FILE_WATCHER_STRATEGY"),
-		EnableDnsServer:     os.Getenv("LOCALSTACK_ENABLE_DNS_SERVER"),
 		EnableXRayTelemetry: os.Getenv("LOCALSTACK_ENABLE_XRAY_TELEMETRY"),
 		LocalstackIP:        os.Getenv("LOCALSTACK_HOSTNAME"),
 		PostInvokeWaitMS:    os.Getenv("LOCALSTACK_POST_INVOKE_WAIT_MS"),
+		ChmodPaths:          GetenvWithDefault("LOCALSTACK_CHMOD_PATHS", "[]"),
 	}
 }
 
@@ -75,12 +75,12 @@ func UnsetLsEnvs() {
 		"LOCALSTACK_USER",
 		"LOCALSTACK_CODE_ARCHIVES",
 		"LOCALSTACK_HOT_RELOADING_PATHS",
-		"LOCALSTACK_ENABLE_DNS_SERVER",
 		"LOCALSTACK_ENABLE_XRAY_TELEMETRY",
 		"LOCALSTACK_INIT_LOG_LEVEL",
 		"LOCALSTACK_POST_INVOKE_WAIT_MS",
 		"LOCALSTACK_FUNCTION_ACCOUNT_ID",
 		"LOCALSTACK_MAX_PAYLOAD_SIZE",
+		"LOCALSTACK_CHMOD_PATHS",
 
 		// Docker container ID
 		"HOSTNAME",
@@ -139,31 +139,13 @@ func main() {
 	}
 	interop.MaxPayloadSize = payloadSize
 
-	// enable dns server
-	dnsServerContext, stopDnsServer := context.WithCancel(context.Background())
-	go RunDNSRewriter(lsOpts, dnsServerContext)
-
 	// download code archive if env variable is set
 	if err := DownloadCodeArchives(lsOpts.CodeArchives); err != nil {
 		log.Fatal("Failed to download code archives: " + err.Error())
 	}
 
-	// set file permissions of the tmp directory for better AWS parity
-	if err := ChmodRecursively("/tmp", 0700); err != nil {
-		log.Warnln("Could not change file mode recursively of directory /tmp:", err)
-	}
-	// set file permissions of the layers directory for better AWS parity
-	if err := ChmodRecursively("/opt", 0755); err != nil {
-		log.Warnln("Could not change file mode recursively of directory /opt:", err)
-	}
-	// set file permissions of the code directory if at least one layer is present for better AWS parity
-	// Limitation: hot reloading likely breaks file permission parity for /var/task in combination with layers
-	// Heuristic for detecting the presence of layers. It might fail for an empty layer or image-based Lambda.
-	if isDirEmpty, _ := IsDirEmpty("/opt"); !isDirEmpty {
-		log.Debugln("Detected layer present")
-		if err := ChmodRecursively("/var/task", 0755); err != nil {
-			log.Warnln("Could not change file mode recursively of directory /var/task:", err)
-		}
+	if err := AdaptFilesystemPermissions(lsOpts.ChmodPaths); err != nil {
+		log.Warnln("Could not change file mode of code directories:", err)
 	}
 
 	// parse CLI args
@@ -200,8 +182,6 @@ func main() {
 		AddShutdownFunc(func() {
 			log.Debugln("Stopping file watcher")
 			cancelFileWatcher()
-			log.Debugln("Stopping DNS server")
-			stopDnsServer()
 		}).
 		SetExtensionsFlag(true).
 		SetInitCachingFlag(true).

go.mod

@@ -11,7 +11,6 @@ require (
 	github.com/go-chi/chi v4.1.2+incompatible
 	github.com/google/uuid v1.3.0
 	github.com/jessevdk/go-flags v1.5.0
-	github.com/miekg/dns v1.1.50
 	github.com/shirou/gopsutil v2.19.10+incompatible
 	github.com/sirupsen/logrus v1.9.3
 	github.com/stretchr/testify v1.8.4
@@ -26,10 +25,8 @@ require (
 	github.com/jmespath/go-jmespath v0.4.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/stretchr/objx v0.5.0 // indirect
-	golang.org/x/mod v0.8.0 // indirect
 	golang.org/x/net v0.18.0 // indirect
 	golang.org/x/text v0.14.0 // indirect
-	golang.org/x/tools v0.6.0 // indirect
 	gopkg.in/yaml.v2 v2.2.8 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -25,8 +25,6 @@ github.com/jmespath/go-jmespath v0.4.0 h1:BEgLn5cpjn8UN1mAw4NjwDrS35OdebyEtFe+9Y
 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/miekg/dns v1.1.50 h1:DQUfb9uc6smULcREF09Uc+/Gd46YWqJd5DbpPE9xkcA=
-github.com/miekg/dns v1.1.50/go.mod h1:e3IlAVfNqAllflbibAZEWOXOQ+Ynzk/dDozDxY7XnME=
 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=
@@ -43,53 +41,23 @@ github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
-github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
-golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
-golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
-golang.org/x/mod v0.8.0 h1:LUYupSeNrTNCGzR/hVBk2NHZO4hXcVaW1k4Qx7rjPx8=
-golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
-golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
-golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
-golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
-golang.org/x/net v0.0.0-20210726213435-c6fcb2dbf985/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20220127200216-cd36cc0744dd/go.mod h1:CfG3xpIq0wQ8r1q4Su4UZFWDARRcnwPjda9FqA0JpMk=
 golang.org/x/net v0.18.0 h1:mIYleuAkSbHh0tCv7RvjL3F6ZVbLjq4+R7zbOn3Kokg=
 golang.org/x/net v0.18.0/go.mod h1:/czyP5RqHAH4odGYxBJ1qz0+CE5WZ+2j1YgoEo8F2jQ=
-golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.2.0 h1:PUR+T4wwASmuSTYdKjYHI5TD22Wy5ogLU5qZCOLxBrI=
 golang.org/x/sync v0.2.0/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 v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220908164124-27713097b956/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.14.0 h1:Vz7Qs629MkJkGyHxUlRHizWJRG2j8fbQKjELVSNhy7Q=
 golang.org/x/sys v0.14.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-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/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 v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
 golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
 golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 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=
-golang.org/x/tools v0.1.6-0.20210726203631-07bc1bf47fb2/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
-golang.org/x/tools v0.6.0 h1:BOw41kyTf3PuCW1pVQf8+Cyg8pMlkYB1oo9iJ6D/lKM=
-golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
-golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/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 h1:obN1ZagJSUGI0Ek/LBmuj4SNLPfIny3KsKFopxRdj10=