From 434763649629eae7ae0de14a7350bebfa36875a7 Mon Sep 17 00:00:00 2001
From: Alex <a@tushynski.me>
Date: Wed, 16 Sep 2026 22:01:39 +0100
Subject: [PATCH] fix: stage a restored volume under /tmp, where the image can
 write

The image does not run as root, so the staging directory could not be created
at the container root: `mkdir /stage` failed with permission denied and every
restore would have failed. It goes under /tmp now, and the command is built as
one string instead of concatenated pieces inside the argument list.

Checked against a real volume and the published image: a truncated tar fails
and leaves the volume exactly as it was, and a whole one restores it.
---
 docsgpt/deploy/docker.py    | 14 +++++++++-----
 tests/deploy/test_docker.py |  3 ++-
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/docsgpt/deploy/docker.py b/docsgpt/deploy/docker.py
index c44eb241..2b3dcdfa 100644
--- a/docsgpt/deploy/docker.py
+++ b/docsgpt/deploy/docker.py
@@ -117,13 +117,17 @@ class Docker:
 
     def import_volume(self, volume: str, source: Path, image: str) -> None:
         """Replace ``volume``'s contents with the tar at ``source``; the volume is created when missing."""
+        # Unpack into the container's own filesystem first, so a truncated or corrupt tar fails
+        # before the live volume is touched rather than halfway through emptying it. It goes under
+        # /tmp because the image does not run as root and cannot write to /.
+        staging = "/tmp/docsgpt-restore"
+        script = (
+            f"set -e; rm -rf {staging}; mkdir -p {staging}; tar xf - -C {staging}; "
+            f"find /data -mindepth 1 -delete; tar cf - -C {staging} . | tar xf - -C /data"
+        )
         with source.open("rb") as handle:
             self._run(
-                ["docker", "run", "--rm", "-i", "-v", f"{volume}:/data", image, "sh", "-c",
-                 # Unpack into the container's own filesystem first: a truncated or corrupt tar must
-                 # fail before the live volume is touched, not halfway through emptying it.
-                 "set -e; rm -rf /stage; mkdir /stage; tar xf - -C /stage; "
-                 "find /data -mindepth 1 -delete; tar cf - -C /stage . | tar xf - -C /data"],
+                ["docker", "run", "--rm", "-i", "-v", f"{volume}:/data", image, "sh", "-c", script],
                 stdin=handle,
             )
 
diff --git a/tests/deploy/test_docker.py b/tests/deploy/test_docker.py
index 61c15dd8..0f1a3e8b 100644
--- a/tests/deploy/test_docker.py
+++ b/tests/deploy/test_docker.py
@@ -130,7 +130,8 @@ class TestVolumes:
         assert args[-2] == "-c"
         assert "tar xf - -C /data" in args[-1]
         command = args[-1]
-        assert command.index("tar xf - -C /stage") < command.index("find /data -mindepth 1 -delete"), (
+        assert "mkdir -p /tmp/" in command, "the image does not run as root, so staging goes under /tmp"
+        assert command.index("tar xf - -C /tmp/") < command.index("find /data -mindepth 1 -delete"), (
             "the incoming tar is unpacked outside the volume first, so a corrupt one leaves it alone"
         )
         assert runner.streams[0][1] is not None, "the tar is fed in on stdin"