simplify unix socket permission format (#3014)

### Pull Request Checklist

<!-- Please read
https://matrix-org.github.io/dendrite/development/contributing before
submitting your pull request -->

* [x] I have added Go unit tests or [Complement integration
tests](https://github.com/matrix-org/complement) for this PR _or_ I have
justified why this PR doesn't need tests
* [x] Pull request includes a [sign off below using a legally
identifiable
name](https://matrix-org.github.io/dendrite/development/contributing#sign-off)
_or_ I have already signed off privately

Signed-off-by: `Boris Rybalkin <[email protected]>`

Author: cyberb

cmd/dendrite/main.go

@@ -16,7 +16,6 @@ package main
 
 import (
 	"flag"
-	"io/fs"
 
 	"github.com/sirupsen/logrus"
 
@@ -34,8 +33,8 @@ var (
 	unixSocket = flag.String("unix-socket", "",
 		"EXPERIMENTAL(unstable): The HTTP listening unix socket for the server (disables http[s]-bind-address feature)",
 	)
-	unixSocketPermission = flag.Int("unix-socket-permission", 0755,
-		"EXPERIMENTAL(unstable): The HTTP listening unix socket permission for the server",
+	unixSocketPermission = flag.String("unix-socket-permission", "755",
+		"EXPERIMENTAL(unstable): The HTTP listening unix socket permission for the server (in chmod format like 755)",
 	)
 	httpBindAddr  = flag.String("http-bind-address", ":8008", "The HTTP listening port for the server")
 	httpsBindAddr = flag.String("https-bind-address", ":8448", "The HTTPS listening port for the server")
@@ -59,7 +58,11 @@ func main() {
 		}
 		httpsAddr = https
 	} else {
-		httpAddr = config.UnixSocketAddress(*unixSocket, fs.FileMode(*unixSocketPermission))
+		socket, err := config.UnixSocketAddress(*unixSocket, *unixSocketPermission)
+		if err != nil {
+			logrus.WithError(err).Fatalf("Failed to parse unix socket")
+		}
+		httpAddr = socket
 	}
 
 	options := []basepkg.BaseDendriteOptions{}

setup/base/base_test.go

@@ -76,7 +76,7 @@ func TestLandingPage_UnixSocket(t *testing.T) {
 	tempDir := t.TempDir()
 	socket := path.Join(tempDir, "socket")
 	// start base with the listener and wait for it to be started
-	address := config.UnixSocketAddress(socket, 0755)
+	address, err := config.UnixSocketAddress(socket, "755")
 	assert.NoError(t, err)
 	go b.SetupAndServeHTTP(address, nil, nil)
 	time.Sleep(time.Millisecond * 100)

setup/config/config_address.go

@@ -3,6 +3,7 @@ package config
 import (
 	"io/fs"
 	"net/url"
+	"strconv"
 )
 
 const (
@@ -32,8 +33,12 @@ func (s ServerAddress) Network() string {
 	}
 }
 
-func UnixSocketAddress(path string, perm fs.FileMode) ServerAddress {
-	return ServerAddress{Address: path, Scheme: NetworkUnix, UnixSocketPermission: perm}
+func UnixSocketAddress(path string, perm string) (ServerAddress, error) {
+	permission, err := strconv.ParseInt(perm, 8, 32)
+	if err != nil {
+		return ServerAddress{}, err
+	}
+	return ServerAddress{Address: path, Scheme: NetworkUnix, UnixSocketPermission: fs.FileMode(permission)}, nil
 }
 
 func HTTPAddress(urlAddress string) (ServerAddress, error) {

setup/config/config_address_test.go

@@ -20,6 +20,24 @@ func TestHttpAddress_ParseBad(t *testing.T) {
 }
 
 func TestUnixSocketAddress_Network(t *testing.T) {
-	address := UnixSocketAddress("/tmp", fs.FileMode(0755))
+	address, err := UnixSocketAddress("/tmp", "0755")
+	assert.NoError(t, err)
 	assert.Equal(t, "unix", address.Network())
 }
+
+func TestUnixSocketAddress_Permission_LeadingZero_Ok(t *testing.T) {
+	address, err := UnixSocketAddress("/tmp", "0755")
+	assert.NoError(t, err)
+	assert.Equal(t, fs.FileMode(0755), address.UnixSocketPermission)
+}
+
+func TestUnixSocketAddress_Permission_NoLeadingZero_Ok(t *testing.T) {
+	address, err := UnixSocketAddress("/tmp", "755")
+	assert.NoError(t, err)
+	assert.Equal(t, fs.FileMode(0755), address.UnixSocketPermission)
+}
+
+func TestUnixSocketAddress_Permission_NonOctal_Bad(t *testing.T) {
+	_, err := UnixSocketAddress("/tmp", "855")
+	assert.Error(t, err)
+}