envd crashes with "fatal error: bad summary data" after Firecracker
snapshot/restore because the page allocator radix tree is inconsistent
when vCPUs are frozen mid-allocation. The port scanner goroutine
allocates heavily every second, making it the primary trigger.
Add POST /snapshot/prepare to envd — the host agent calls it before
vm.Pause to quiesce continuous goroutines and force GC. On restore,
PostInit restarts the port subsystem via the existing /init endpoint.
- New PortSubsystem abstraction with Start/Stop/Restart lifecycle
- Context-based goroutine cancellation (replaces irreversible channel close)
- Context-aware Signal to prevent scanner/forwarder deadlock
- Fix forwarder goroutine leak (was spinning forever on closed channel)
- Kill socat children on stop to prevent orphans across snapshots
- Fix double cmd.Wait panic (exec.Command instead of CommandContext)
Implement three new recipe commands for the admin template builder:
- USER <name>: creates the user (adduser + passwordless sudo), switches
execution context so subsequent RUN/START commands run as that user
via su wrapping. Last USER becomes the template's default_user.
- COPY <src> <dst>: copies files from an uploaded build archive
(tar/tar.gz/zip) into the sandbox. Source paths validated against
traversal. Ownership set to the current USER.
- ENV persistence: accumulated env vars stored in templates.default_env
(JSONB) and injected via PostInit when sandboxes are created from the
template, mirroring Docker's image metadata approach.
Supporting changes:
- Pre-build creates wrenn-user as default (via USER command)
- WORKDIR now creates the directory if it doesn't exist (mkdir -p)
- Per-step progress updates (ProgressFunc callback) for live UI
- Multipart form support on POST /v1/admin/builds for archive upload
- Proto: default_user/default_env fields on Create/ResumeSandboxRequest
- Host agent: SetDefaults calls PostInitWithDefaults on envd
- Control plane: reads template defaults, passes on sandbox create/resume
- Frontend: file upload widget, recipe copy button, keyword colors for
USER/COPY, fixed Svelte whitespace stripping in step display
- Admin panel defaults to /admin/templates instead of /admin/hosts
- Migration adds default_user and default_env to templates and
template_builds tables
Wire envd's existing PTY process capabilities through the full stack:
hostagent proto (4 new RPCs: PtyAttach, PtySendInput, PtyResize, PtyKill),
envdclient, sandbox manager, and a new WebSocket endpoint at
GET /v1/sandboxes/{id}/pty with bidirectional JSON message protocol.
Sessions use tag-based identity for disconnect/reconnect support,
base64-encoded PTY data for binary safety, and a 120s inactivity timeout.
After restoring a VM from snapshot, envd had already completed its initial
MMDS poll, so the metadata files in /run/wrenn/ and env vars retained values
from the original sandbox. Call POST /init after WaitUntilReady on both
resume and create-from-template paths to trigger envd to re-read MMDS.
Plumb ListDir, MakeDir, and RemovePath through all layers:
REST API → host agent RPC → envdclient → envd. These endpoints
enable a web file browser for sandbox filesystem interaction.
New endpoints (all under requireAPIKeyOrJWT):
- POST /v1/sandboxes/{id}/files/list
- POST /v1/sandboxes/{id}/files/mkdir
- POST /v1/sandboxes/{id}/files/remove
