[ISSUE-199] Per-sandbox symlink layer for all mount sources - #200
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[ISSUE-199] Per-sandbox symlink layer for all mount sources#2001996fanrui wants to merge 2 commits into
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Introduce a per-sandbox staging directory under SandboxDataRoot for
all mount sources (builtin tools and generic mounts). Each mount source
gets a staging entry named {md5(abs_path)}_{basename} in a flat directory.
The current implementation uses symlinks — Docker bind-mount follows symlinks
natively, enabling per-sandbox mount source management with no Docker-side changes.
Key changes:
- Add SandboxDataRoot() platform path (~/.local/share/agents-sandbox/mounts)
- Add createMountSymlink() helper with MD5 naming and idempotent behavior
- Rename SymlinkDir to MountStagingDir in sandboxRuntimeState
- Update materializeBuiltinTools/materializeGenericMounts to stage mount sources
- Docker Desktop magic path (/run/host-services/ssh-auth.sock) bypasses staging
- Allow symlink mount sources in validation (mount only, copy still rejected)
- Set MountStagingDir in restart recovery, preserve runtimeState for cleanup
- Clean up staging directory in deleteRuntimeArtifacts
Closes: #199
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Update four design documents to reflect the new mount staging layer: - configuration_reference.md: add SandboxDataRoot to Fixed Platform Paths - daemon_state_management.md: add MountStagingDir to Category C, staging dir to Category D - sandbox_container_lifecycle.md: add staging dir creation step in Create Path - container_dependency_strategy.md: update mount/copy/builtin staging handling Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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Summary
Introduce a per-sandbox symlink directory for all mount sources (builtin tools and generic mounts). Instead of bind-mounting original host paths directly into containers, the daemon now creates a symlink in
~/.local/share/agents-sandbox/mounts/<sandbox_id>/pointing to each original path, and uses the symlink as the bind-mount source. Docker follows symlinks during bind-mount, so this requires no Docker-side changes.close #199
Changes
Core Implementation
internal/platform/dirs.go): AddSandboxDataRoot()following theExecLogRoot()patterninternal/control/service.go,cmd/agboxd/config.go): AddSandboxDataRootfield toServiceConfig, initialize from platform defaultinternal/control/docker_runtime_materialize.go): NewcreateMountSymlinkfunction withmd5(abs_path)_<basename>naming, idempotent semanticsinternal/control/docker_runtime.go): ExtendsandboxRuntimeStatewithSymlinkDir, create symlink dir inCreateSandbox, clean up indeleteRuntimeArtifactsmaterializeBuiltinTools,materializeBuiltinToolPath,materializeGenericMountsto route through symlink layerinternal/control/service_validation.go): Allow symlink sources for mount kind (usesos.Stat), keep rejecting for copy kind (usesos.Lstat)internal/control/service_events.go): RebuildSymlinkDirfromSandboxDataRoot + sandboxIDon restart, preserveruntimeStatefor all terminal statesSpecial Cases
/run/host-services/ssh-auth.sock) bypasses symlink layerSandboxDataRootis empty, all functions fall back to original behavior (no symlinks)Documentation
docs/configuration_reference.md: Add Sandbox data to Fixed Platform Paths tabledocs/daemon_state_management.md: AddSymlinkDirto Category C, symlink directory to Category Ddocs/sandbox_container_lifecycle.md: Add symlink dir creation step in Create Pathdocs/container_dependency_strategy.md: Update mount source rules for symlink layerTests
docker_runtime_symlink_test.go(414 lines): symlink naming, idempotency, replacement, normalization, builtin tools, generic mounts (dir/file/socket), magic path bypass, cleanup, fallback behaviorTestCreateSandboxCreatesSymlinkDir: verifies symlink dir created via Docker runtimeTestRestorePersistedSandboxesSetsSymlinkDir: verifies restart recovery rebuilds SymlinkDir