Before this change there were two callers of left4me-overlay mount:
the web app's start_instance (Python, in-process) and the unit's
ExecStartPre (shell, via sudo). The duplication invited divergence; the
helper's recently-added idempotency made both paths technically work
but at the cost of a "first wins" race and dead-code retry logic in
start_instance.
Drop the in-process _mounter.mount() call from start_instance. The web
app now only stages cfg files (which still must happen on the host
filesystem before mount, to avoid overlayfs copy-up changing ownership),
then asks systemd to enable+start the unit; the unit's ExecStartPre
does the mount.
Removed:
- os.path.ismount(merged) refusal in start_instance and its test
(test_start_refuses_to_double_mount). The race the check guarded
against is now handled by the helper's idempotency.
- _load_instance_env helper and the `os` import (both became dead).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Servers started via the web UI now create a WantedBy= symlink under
multi-user.target.wants/, so they auto-start on the next host reboot.
Helper verbs renamed start/stop -> enable/disable; service_control.py
renamed start_service/stop_service -> enable_service/disable_service.
The user-facing l4d2ctl start/stop commands keep their names per the
AGENTS.md contract -- only the implementation changes. Spec:
docs/superpowers/specs/2026-05-09-l4d2-server-lifecycle-reboot-and-drift-design.md
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Each linked overlay gets a checkbox on the blueprint detail page that opts
its server.cfg in as exec server_overlay_<id>. The web app builds the
spec with {path, alias} per overlay and prepends exec server_overlay_<id>
lines to the blueprint config in lowest-overlay-first order. The host
stages those copies in the overlayfs upper layer before mounting (avoids
copy-up writes against a sandbox-uid file). A live preview block above the
Config textarea shows what gets auto-executed.
Schema:
- alembic 0007: BlueprintOverlay.expose_server_cfg BOOLEAN
Spec contract:
- l4d2host OverlayRef(path, alias?). load_spec accepts both bare-string
and {path, alias} entries.
Side effects folded in (same file in l4d2_facade):
- start_server auto-initializes; the manual Initialize step is no longer
needed before Start.
- initialize_server no longer runs blueprint builders — builds happen on
overlay save, not on every server Start.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Reset stops the systemd service, unmounts the overlay, and rm -rf's both
runtime/<name> and instances/<name>, but keeps the Server row, blueprint,
and (shared) systemd template. Next Start re-initializes from the current
blueprint, so users can clean up logs/caches/accumulated game state without
losing the server.
Implementation factors a shared _purge_instance helper out of
delete_instance; reset_instance reuses it without the existence guard. New
"reset" lifecycle op flows through the same route + worker + facade plumbing
as the other server ops.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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>
