From eb4435bf74018107915d03d250a78f0fe7541ef3 Mon Sep 17 00:00:00 2001
From: Eno Compton <enocom@google.com>
Date: Thu, 25 Apr 2024 17:01:28 -0600
Subject: [PATCH] fix: ensure graceful shutdown on fuse error (#638)

If the FUSE mount has not succeeded due to misconfiguration, the Proxy
should still shutdown without panicing.

Related to https://github.com/GoogleCloudPlatform/cloud-sql-proxy/issues/2013
---
 internal/proxy/proxy_other.go      |  3 +++
 internal/proxy/proxy_other_test.go | 19 +++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/internal/proxy/proxy_other.go b/internal/proxy/proxy_other.go
index 7da711d0..96a29904 100644
--- a/internal/proxy/proxy_other.go
+++ b/internal/proxy/proxy_other.go
@@ -181,6 +181,9 @@ func (c *Client) fuseMounts() []*socketMount {
 func (c *Client) unmountFUSE() error {
 	c.fuseServerMu.Lock()
 	defer c.fuseServerMu.Unlock()
+	if c.fuseServer == nil {
+		return nil
+	}
 	return c.fuseServer.Unmount()
 }
 
diff --git a/internal/proxy/proxy_other_test.go b/internal/proxy/proxy_other_test.go
index 75e33e2b..6cf701b1 100644
--- a/internal/proxy/proxy_other_test.go
+++ b/internal/proxy/proxy_other_test.go
@@ -18,8 +18,11 @@
 package proxy_test
 
 import (
+	"context"
 	"os"
 	"testing"
+
+	"github.com/GoogleCloudPlatform/alloydb-auth-proxy/internal/proxy"
 )
 
 func verifySocketPermissions(t *testing.T, addr string) {
@@ -31,3 +34,19 @@ func verifySocketPermissions(t *testing.T, addr string) {
 		t.Fatalf("file mode: want = %v, got = %v", 0777|os.ModeSocket, fm)
 	}
 }
+
+func TestFuseClosesGracefully(t *testing.T) {
+	c, err := proxy.NewClient(
+		context.Background(), nil, testLogger,
+		&proxy.Config{
+			FUSEDir:     t.TempDir(),
+			FUSETempDir: t.TempDir(),
+			Token:       "mytoken",
+		})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := c.Close(); err != nil {
+		t.Fatal(err)
+	}
+}