Drop MountFlags=shared (the assumption that it propagated fuse mounts
to host was incorrect on systemd 257 with ProtectSystem+ReadWritePaths).
Restore PrivateTmp=true (was dropped in 593611e for fuse propagation
that did not work). Rewrite the comment block to describe the new
model: mounts go through the left4me-overlay helper which nsenters
into PID 1's mount namespace, so the unit's mount-ns layout is no
longer load-bearing.
Update the three user-facing READMEs (root, l4d2host, deploy) to drop
fuse-overlayfs / fusermount3 prereqs and call out the kernel overlayfs
mount path through the privileged helper.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Replace direct fuse-overlayfs / fusermount3 subprocess calls in
start_instance / stop_instance / delete_instance with the existing
OverlayMounter abstraction, now backed by KernelOverlayFSMounter.
Adds an os.path.ismount guard at the top of start_instance so a
kernel-level overlay that survived a web-worker crash isn't double-
mounted (kernel mounts persist when the cgroup dies, unlike fuse
daemons).
Delete the unused FuseOverlayFSMounter module.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
New privileged helper at /usr/local/libexec/left4me/left4me-overlay
(Python, system /usr/bin/python3, stdlib only) takes only the instance
name, parses instance.env for L4D2_LOWERDIRS, validates each lowerdir
against an allowlist (installation/, overlays/, global_overlay_cache/,
workshop_cache/), refuses upperdirs tainted with user.fuseoverlayfs.*
xattrs from the prior fuse era, and execs `nsenter --mount=/proc/1/ns/mnt
-- mount -t overlay ...` so the resulting mount lives in the host
namespace. Mirrors the existing left4me-systemctl / left4me-journalctl
pattern; sudoers entry is verb-constrained.
KernelOverlayFSMounter implements the existing OverlayMounter ABC,
deriving the instance name from the merged path. No call sites use it
yet — that's the next commit.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
systemctl stop is already a no-op on a stopped unit, but stop_instance
was unconditionally running fusermount3 -u and bubbling up the EINVAL
when the overlay wasn't currently mounted (e.g. server already stopped).
Mirror the established delete_instance pattern: always attempt the
unmount, swallow CalledProcessError, and label the step "(if mounted)".
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
L4D2 dedicated server expects to dlopen steamclient.so via
~/.steam/sdk32 (and sdk64). Without those symlinks, srcds_run logs
'cannot open shared object file' and SteamAPI_Init fails, which means
the server is invisible to the public Steam master server, Workshop
addon downloads break, and Steam 'Join Game' / lobby joins do not
reach the server (only direct-IP connect works).
SteamInstaller.install_or_update now ensures the symlinks exist after
SteamCMD finishes. Targets prefer SteamCMD's linux32/linux64 sibling
dirs; falls back to <install_dir>/bin/ if the siblings cannot be
located. Idempotent: re-running the install repairs or leaves the
symlinks alone.
Path.home() respects HOME, which the systemd web unit sets to
/var/lib/left4me, so the symlinks land in the left4me user's home.
Existing deploys can apply the fix by re-running 'Install' from /admin
without a full redeploy.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
- validate instance names at the host lib and web boundary against
[a-z0-9][a-z0-9_-]{0,63} to prevent path traversal via Server.name
- fail-closed on SECRET_KEY: load_config returns None when env unset,
create_app raises if missing or "dev" outside TESTING
- close login timing oracle by hashing a dummy digest when the user
is not found, equalizing response time
- set SESSION_COOKIE_SECURE outside TESTING
- delete_instance tolerates stop_service and fusermount3 failures so
partially-initialized instances clean up without contract breaks;
drops the is_mount() preflight that violated AGENTS.md
- document claim_next_job's single-process assumption
- clarify emit_step contract via docstring
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
