feat(backend-kubernetes): launch thread-bound Agent Sandbox sessions by tee8z · Pull Request #12 · voltagecloud/buzz

tee8z · 2026-10-19T20:52:47Z

Launch thread-bound Agent Sandbox sessions through the Kubernetes provider. Verify the owner identity and launch intent, bind the first Pod, and deliver credentials through the scoped launch Secret. Existing bare-Pod operation remains available when Sandbox mode is omitted. Sandbox mode refuses to launch unless BUZZ_CHECKPOINT_BUCKET and BUZZ_CHECKPOINT_PREFIX are set and non-blank, because the stop checkpoint is the only copy of the emptyDir workspace; BUZZ_SANDBOX_CHECKPOINT=disabled opts out explicitly.

Validation: the integrated provider suite passed, including binding and credential failure paths. Deployment of the Sandbox controller, worker templates, and cluster permissions remains an infrastructure prerequisite.

Stack: layer 9 of 24. Base: #11. Next: #1. One signed commit per layer.

Final integrated checks passed: ACP/provider/reaper tests and Clippy; 3,451 native desktop tests (19 ignored); native Clippy; desktop TypeScript and lint; root security; and file-size checks. The frontend run passed 7,008 tests before the final type-only extraction and test formatting. Repository-wide just ci and GitHub CI are still running. No human runtime acceptance is claimed.

The Sandbox JSON Schema accepts false or the exact bound-scope object, with canonical IDs and no extra properties. An explicit UI annotation preserves desktop boolean configuration until launch binds the thread. Include owner in the harness-mode deployability test. Validation: 180 provider tests, 14 frontend tests, TypeScript checking, and 11 cases against the actual provider schema passed.

Summary by CodeRabbit

New Features
- Added optional Kubernetes Agent Sandbox workspaces scoped to channels and threads.
- Added workspace reuse, ownership validation, credential binding, checkpointing, and recovery safeguards.
- Added support for the owner response mode.
- Added UI support for configuring deferred Sandbox settings as boolean values.
Documentation
- Documented Sandbox configuration, required environment settings, lifecycle behavior, and local testing procedures.
Tests
- Added coverage for workspace creation, reuse, validation, checkpointing, and controller lifecycle scenarios.

coderabbitai · 2026-10-19T23:28:23Z

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📒 Files selected for processing: 10

crates/buzz-acp/TESTING.md
crates/buzz-backend-kubernetes/Cargo.toml
crates/buzz-backend-kubernetes/src/config.rs
crates/buzz-backend-kubernetes/src/env.rs
crates/buzz-backend-kubernetes/src/main.rs
crates/buzz-backend-kubernetes/src/sandbox.rs
crates/buzz-backend-kubernetes/src/sandbox_tests.rs
desktop/src/features/agents/ui/ProviderConfigFields.test.mjs
desktop/src/features/agents/ui/ProviderConfigFields.tsx
docs/remote-agents.md

📝 Walkthrough

Adds a sandbox option to the Kubernetes backend. The backend validates thread scope and identity, creates or reuses managed Kubernetes Sandboxes, binds credentials to the initial Pod, and rejects mismatched or replaced resources. Tests, UI coercion, and documentation cover the lifecycle.

Changes: Agent Sandbox workspaces

Layer / File(s)	Summary
Sandbox configuration and identity gates `crates/buzz-backend-kubernetes/Cargo.toml`, `crates/buzz-backend-kubernetes/src/config.rs`, `crates/buzz-backend-kubernetes/src/env.rs`, `crates/buzz-backend-kubernetes/src/main.rs`, `desktop/src/features/agents/ui/*`, `docs/remote-agents.md`	Adds the `sandbox` schema, the `owner` response gate, deferred boolean coercion, and sandbox deployment dispatch.
Sandbox scope and resource validation `crates/buzz-backend-kubernetes/src/sandbox.rs`, `crates/buzz-backend-kubernetes/src/sandbox_tests.rs`	Validates channel and thread scope, constructs managed Sandbox resources, configures ACP and Codex setup, and tests resource ownership and checkpoint behavior.
Deployment and lifecycle checks `crates/buzz-backend-kubernetes/src/sandbox.rs`, `crates/buzz-backend-kubernetes/src/sandbox_tests.rs`, `crates/buzz-acp/TESTING.md`, `docs/remote-agents.md`	Creates or reuses matching Sandboxes, binds credentials to the first Pod UID, validates startup and recovery conditions, and documents and tests reuse, refusal, and replacement behavior.

Priority: ⬆️ High

Estimated code review effort: 4 (Complex) | ~60 minutes

Change: Feature · Unblocks: 15 PRs

Sequence Diagram(s)

sequenceDiagram
  participant deploy_agent
  participant sandbox_deploy
  participant Kubernetes_API
  participant Sandbox_controller
  deploy_agent->>sandbox_deploy: pass identity, scope, owner, and environment
  sandbox_deploy->>Kubernetes_API: create or retrieve named Sandbox
  Kubernetes_API-->>sandbox_deploy: return Sandbox resource
  Sandbox_controller->>Kubernetes_API: create controller-owned Pod
  sandbox_deploy->>Kubernetes_API: wait for Pod and bind credentials to Pod UID
  Kubernetes_API-->>sandbox_deploy: return Pod identity and binding result
  sandbox_deploy-->>deploy_agent: return deployment result

Suggested reviewers: tlongwell-block

Merge Risk: 🔵 Low · up to df6a2

This change adds thread-bound Agent Sandbox launches to the Kubernetes provider. One bounded gap remains: if an operator sets the checkpoint bucket or prefix to an empty value, the launch succeeds, but the checkpoint save fails when the session stops. That session's workspace is then lost. The fix is a small validation tweak. The provider schema now matches the configuration shapes that deploy accepts.

Pre-merge checks: 4 · 1

Failed checks: 1 warning

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 52.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 25 functions across 7 files. (3 skipped: …	Write docstrings for the functions missing them to satisfy the coverage threshold.

Passed checks: 4 passed

Check name	Status	Explanation
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Title check		The title clearly and concisely describes the main change: launching thread-bound Agent Sandbox sessions through the Kubernetes backend.
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

Full details: Docstring Coverage

Explanation

Docstring coverage is 52.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 25 functions across 7 files. (3 skipped: 3 unsupported.)

Resolution

Write docstrings for the functions missing them to satisfy the coverage threshold.

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tee8z · 2026-10-20T15:04:13Z

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Please review the current revision against this PR’s immediate stack base. The descriptions document the remote-agent scope, regression coverage, and outstanding runtime validation.

coderabbitai · 2026-10-20T15:04:39Z

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tee8z · 2026-10-20T16:07:23Z

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tee8z · 2026-10-20T16:08:53Z

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coderabbitai · 2026-10-20T16:09:01Z

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Inline comments:
Review comments at @docs/remote-agents.md:
- Around line 1423-1425: The documented desktop workflow must not claim that
sandbox=true is supported when provider_config is forwarded unchanged and
Options::parse requires scoped identifiers. Update the desktop flow to translate
the published mention’s channel and canonical thread root into the sandbox
object before provider invocation, or remove the desktop workflow documentation
until that translation exists.

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crates/buzz-acp/TESTING.md
crates/buzz-backend-kubernetes/Cargo.toml
crates/buzz-backend-kubernetes/src/config.rs
crates/buzz-backend-kubernetes/src/env.rs
crates/buzz-backend-kubernetes/src/main.rs
crates/buzz-backend-kubernetes/src/sandbox.rs
crates/buzz-backend-kubernetes/src/sandbox_tests.rs
docs/remote-agents.md

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tee8z · 2026-10-20T23:29:27Z

@tee8z CodeRabbit review needs attention: review finished without a verified clean result. This PR remains draft until the findings are addressed and reviewed.

feat(backend-kubernetes): launch thread-bound Agent Sandbox sessions #12 (comment)

tee8z · 2026-10-20T23:33:41Z

@tee8z CodeRabbit review needs attention: actionable review comments remain. This PR remains draft until the findings are addressed and reviewed.

feat(backend-kubernetes): launch thread-bound Agent Sandbox sessions #12 (comment)

tee8z · 2026-10-20T23:48:19Z

@tee8z CodeRabbit review needs attention: actionable review comments remain. This PR remains draft until the findings are addressed and reviewed.

feat(backend-kubernetes): launch thread-bound Agent Sandbox sessions #12 (comment)

tee8z · 2026-10-21T03:03:02Z

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coderabbitai · 2026-10-21T03:03:08Z

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Actionable comments posted: 1

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minimal, and validate.

Inline comments:
Review comments at @crates/buzz-backend-kubernetes/src/sandbox.rs:
- Around line 203-214: Update the checkpoint gate in apply_session_env to treat
BUZZ_CHECKPOINT_BUCKET and BUZZ_CHECKPOINT_PREFIX as configured only when their
values are non-empty after trimming whitespace. Use this validation for both
keys before setting BUZZ_ACP_CHECKPOINT_ON_STOP, while preserving the existing
opt-out and missing-configuration error behavior.

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crates/buzz-acp/TESTING.md
crates/buzz-backend-kubernetes/Cargo.toml
crates/buzz-backend-kubernetes/src/config.rs
crates/buzz-backend-kubernetes/src/env.rs
crates/buzz-backend-kubernetes/src/main.rs
crates/buzz-backend-kubernetes/src/sandbox.rs
crates/buzz-backend-kubernetes/src/sandbox_tests.rs
desktop/src/features/agents/ui/ProviderConfigFields.test.mjs
desktop/src/features/agents/ui/ProviderConfigFields.tsx
docs/remote-agents.md

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tee8z · 2026-10-21T03:09:21Z

@tee8z CodeRabbit review needs attention: actionable review comments remain. This PR remains draft until the findings are addressed and reviewed.

feat(backend-kubernetes): launch thread-bound Agent Sandbox sessions #12 (comment)

tee8z · 2026-10-21T03:09:22Z

@tee8z CodeRabbit review needs attention: review finished without a verified clean result. This PR remains draft until the findings are addressed and reviewed.

feat(backend-kubernetes): launch thread-bound Agent Sandbox sessions #12 (comment)

Add an opt-in sandbox mode that creates one agents.x-k8s.io/v1beta1 Sandbox per agent, channel, and canonical thread root. A matching running Sandbox is reused; a changed, replaced, or completed one requires explicit recovery instead of a silent empty replacement. The provider requires the identity policy and an absolute Pod deadline, binds the launch Secret to the first Pod UID, configures the harness for owner-only bound thread sessions with activity logging, and supports Codex device account setup. Sandbox Pods use the bare-Pod termination grace, which covers the drain and the stop checkpoint. Because the workspace does not outlive the Pod, deploy refuses Sandbox mode unless BUZZ_CHECKPOINT_BUCKET and BUZZ_CHECKPOINT_PREFIX enable the stop checkpoint, or BUZZ_SANDBOX_CHECKPOINT=disabled opts out. The env guard now accepts the harness's strict owner respond-to mode. Signed-off-by: Tee8z <[email protected]>

tee8z · 2026-10-21T13:16:40Z

CI note: this stack still hits flaky tests in code it does not change. When one of these fails here, the failure is unrelated to this PR, and a re-run usually passes.

buzz-cli client::retry_policy_tests::exhausted_connect_failures_return_network_retryable: a parallel test can take the freed port and answer with HTTP 405.
Desktop smoke E2E huddle-transcription.spec.ts and empty-edit-delete.spec.ts: upstream fix test: fix recurring CI flakes in desktop and Postgres lanes block/buzz#8343, backported in fix(ci): stabilize fork publishing and desktop smoke fixtures #24.
buzz-db cluster-wide replica_fence PostgreSQL tests: fixed in fix(ci): stabilize PostgreSQL concurrency tests #31 for the layers above it.
buzz-agent steer_rejected_on_run_id_mismatch: fixed in test(agent): wait for both responses in the steer run-id mismatch test #33 for the layers above it.
buzz-acp adapter-spawn tests that fail with Text file busy (ETXTBSY).

Summary jobs from cancelled runs also stay red until the replacement run finishes. A failure in this PR's own code gets a fix in this PR.

@thebrandonlucas it's fine to approve without CI fully passing.

This was referenced Oct 19, 2026

feat(acp): emit activity records and checkpoint on stop #11

Merged

feat(desktop): start thread-bound remote sessions from mentions #1

Merged

tee8z added this pull request to stack #22 October 19, 2026 20:56

tee8z self-assigned this Oct 19, 2026

tee8z force-pushed the dev-2884-sandbox-provider branch from e1be0de to 9cdecfe Compare October 19, 2026 23:28

tee8z force-pushed the dev-2884-sandbox-provider branch from 9cdecfe to c735726 Compare October 20, 2026 14:53

tee8z removed this pull request from stack #22 October 20, 2026 14:56

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tee8z force-pushed the dev-2884-sandbox-provider branch from c735726 to 456de66 Compare October 20, 2026 15:35

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Comment thread docs/remote-agents.md Resolved

tee8z force-pushed the dev-2884-sandbox-provider branch from 456de66 to e72e19c Compare October 20, 2026 16:24

tee8z removed this pull request from stack #26 October 20, 2026 16:24

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tee8z force-pushed the dev-2884-sandbox-provider branch from e72e19c to 0bc18a7 Compare October 20, 2026 16:51

tee8z removed this pull request from stack #28 October 20, 2026 17:22

tee8z force-pushed the dev-2884-sandbox-provider branch from 0bc18a7 to 91b47b7 Compare October 20, 2026 17:22

tee8z added this pull request to stack #30 October 20, 2026 17:22

tee8z force-pushed the dev-2884-sandbox-provider branch from 91b47b7 to a0e74d1 Compare October 20, 2026 17:51

tee8z marked this pull request as ready for review October 20, 2026 17:59

tee8z force-pushed the dev-2884-sandbox-provider branch from 341c0d6 to 614c364 Compare October 20, 2026 23:33

tee8z force-pushed the dev-2884-sandbox-provider branch from 614c364 to 9a686d8 Compare October 20, 2026 23:47

tee8z force-pushed the dev-2884-sandbox-provider branch 2 times, most recently from d60de9c to df6a2b2 Compare October 21, 2026 00:49

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Comment thread crates/buzz-backend-kubernetes/src/sandbox.rs Resolved

tee8z force-pushed the dev-2884-sandbox-provider branch from df6a2b2 to c1e669d Compare October 21, 2026 12:20

tee8z removed this pull request from stack #32 October 21, 2026 12:21

tee8z added this pull request to stack #34 October 21, 2026 12:21

tee8z marked this pull request as ready for review October 21, 2026 12:37

tee8z force-pushed the dev-2884-sandbox-provider branch from c1e669d to b03f007 Compare October 21, 2026 12:55

tee8z added the human review wanted Request human review label Oct 21, 2026

thebrandonlucas approved these changes Oct 21, 2026

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tee8z merged commit 8e74a69 into main Oct 21, 2026
107 of 130 checks passed

tee8z deleted the dev-2884-sandbox-provider branch October 21, 2026 13:27

This was referenced Oct 21, 2026

feat(gpui): run remote workspace sessions through the Kubernetes provider #54

Merged

feat(gpui): add the remote workspace agent type #55

Merged

feat(mobile): launch remote agents from channel mentions #83

Merged

coderabbitai Bot mentioned this pull request Nov 11, 2026

feat(agents): delegate gateway keys for remote agent access #154

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