feat(logging): tag logs with a per-session ID by aqandrew · Pull Request #1073 · coder/vscode-coder

aqandrew · 2026-08-11T22:26:35Z

What

Introduce a per-session identifier and make the extension tag every log line with it, so all logs for a session can be correlated by searching a single ID.

This is Phase 1 of 3 for DEVEX-661 — "VS Code: add session_id to all requests, logs, existing telemetry, and CLI invocations".

Changes

Add SessionLogger (src/logging/sessionLogger.ts) — a Logger that wraps the Coder output channel and prefixes every message with [<sessionId>].
Generate the session ID once in ServiceContainer (reusing the existing newSessionId() that already backs the telemetry session, so logs, telemetry, requests, and the CLI all share one ID), and expose it via getSessionId() for the later phases.

Because every service already receives Logger by injection, session-tagged logging propagates with no call-site changes.

Design notes

The code owner (Ehab) suggested composing the session ID and the VS Code logger inside container.ts's ServiceContainer; this PR follows that approach. The telemetry sessionId from newSessionId() is the RFC session_id (confirmed with Ehab — reuse it rather than minting a second ID).

Testing

pnpm typecheck, targeted pnpm lint, and pnpm test:extension (full suite: 2108 passing).
New unit tests for SessionLogger prefixing and argument forwarding.

Implementation plan (DEVEX-661)

Thread a single per-session identifier (16-byte / 32-char lowercase hex) so that
logs, API requests, existing telemetry, and the CLI ssh invocation the
extension drives can all be correlated by one session_id.

In-scope RFC requirements

Req	Summary	Where
1	Generate 16-byte / 32-hex session ID	Reuse existing `newSessionId()`
2	Session ID on every client log	Phase 1 (this PR)
3	`session_id` on every API request via baggage	Phase 2
4.2	`session_id` on VS Code telemetry	Phase 2 (already covered by reusing the ID)
5.2/5.3	`CODER_TRACE_SESSION_ID` via `process.env` + terminal env collection	Phase 2
7	Log workspace/agent/lifecycle state changes at `info`	Phase 3
16	Default `--log-dir` + old-log cleanup	Already implemented — verify only

Out of scope: coderd tracing middleware (req 6), agent/coordination-protocol
changes and the CLI ssh subcommand behavior (reqs 8–15) live in coder/coder.
Req 13 (in-memory log buffer flushed on connection failure) is deferred to a
follow-up.

Key decisions

D1 (resolved): the telemetry sessionId is the RFC session_id — one ID,
generated once in ServiceContainer.
D2: session scope is per activation; Remote-SSH opens each workspace in a fresh
activation, so container-scoped ≈ per-connection.
D3 (resolved): prefix every log line with the full 32-hex ID as
[<sessionId>] <message>.
D4: baggage: session_id=<hex> header.

Phases

Session ID + SessionLogger composition in the container (this PR).
Thread the ID to API requests (baggage), telemetry (already covered), and the
CLI via CODER_TRACE_SESSION_ID on process.env + the terminal env
collection.
Log workspace / agent / lifecycle state transitions at info.

🤖 Generated by Coder Agents.

Add SessionLogger, which wraps the Coder output channel and prefixes every message with the activation's session ID so all log lines for a session can be correlated by a single ID. Generate the ID once in the ServiceContainer, reuse it as the telemetry session ID, and expose it via getSessionId() for downstream consumers.

linear-code · 2026-08-11T22:26:38Z

DEVEX-661

…OutputChannel named outputChannel

Replace the SessionLogger class with a prefixLogger(inner, prefix) factory that wraps a Logger and prefixes every message, and rename the module to prefixLogger.ts. The prefix is now generic (a session ID, a workspace name, etc.); the caller passes the bracketed session prefix. Addresses review feedback on #1073.

EhabY · 2026-08-17T12:48:41Z

+		// One session ID per activation, shared by logs, API requests,
+		// telemetry, and the CLI so all data for a session correlates.


Nit: this comment will go once we have a the file with a session ID defined at runtime

Prefix logs with [session <shortId>] and render the HTTP request ID as [request <shortId>] so a line clearly identifies both IDs, e.g. '[session ece5f89f] <- [request 38b0a2b4] 200 GET ...'. The full session ID is unchanged on the wire; only the log representation is shortened.

…v var (#1074) ## What Propagate the session ID from Phase 1 to outbound API requests and to the CLI, so server-side logs, telemetry, and the spawned `coder ssh` process can all be correlated with the extension's session. This is **Phase 2 of 3** for [DEVEX-661](https://linear.app/codercom/issue/DEVEX-661). It builds on #1073. ## Changes - **Requests (RFC req 3):** add a `sessionId` argument to `CoderApi.create` and attach the session ID to every request via the W3C `baggage` header using the `client_session_id` key (`baggage: client_session_id=<hex>`), on both the REST default headers and the WebSocket handshake headers. Threaded through all `CoderApi.create` call sites, including the pre-auth OAuth/login/deployment clients, so every request carries it. - **Telemetry (RFC req 4.2):** already satisfied — the shared ID is the telemetry `sessionId`, which ships on every event's context. - **CLI (RFC reqs 5.2/5.3):** extend `applySshEnvironment` to also set `CODER_TRACE_SESSION_ID` on both `process.env` and the terminal environment collection, so the spawned `coder ssh` ProxyCommand reuses the plugin's session ID instead of generating its own. ## Testing - `pnpm typecheck`, targeted `pnpm lint`, full `pnpm test:extension` (2108 passing). - New tests: `baggage: client_session_id=<hex>` present/absent on `CoderApi`; `CODER_TRACE_SESSION_ID` applied to `process.env` and the terminal collection and restored on dispose. --- 🤖 Generated by Coder Agents.

## What Add info-level logging of workspace, agent, and lifecycle status transitions so connection debugging has a record of state changes — correlated by the session ID from #1073. This is **Phase 3 of 3** for [DEVEX-661](https://linear.app/codercom/issue/DEVEX-661) (RFC req 7). It builds on #1074. ## Changes State handling is split into three layers, one job each: - **detect** — `WorkspaceStateObserver` / `WorkspaceAgentObserver` (`src/instrumentation/workspace.ts`) each detect a transition once and report a transition object. Stateful but effect-free (no logger/telemetry imports). The agent observer tracks every agent by ID and reports agents that disappear. - **record** — `recordWorkspaceState` / `recordAgentState` emit the `workspace.state_transitioned` / `workspace.agent.state_transitioned` telemetry events. - **log** — inline in `WorkspaceMonitor.update()`, with flat scalar payloads matching the repo's other log sites. Logs `state observed` on first sight, `state changed` afterward, and `agent <name> removed` when an agent disappears. `WorkspaceMonitor` is now the single agent-observation site, so `WorkspaceStateMachine` no longer tracks agent telemetry. > [!IMPORTANT] > **Telemetry data change.** `workspace.agent.state_transitioned` now covers **every agent for the whole monitored session** (deduped per agent), rather than only the connected agent during connection setup. In practice most workspaces have one agent, so volume is unchanged; multi-agent workspaces and flaky connections emit more. There is no sampling in `src/telemetry/`, so this lands as-is. `EVENTS.md` is updated; heads-up to whoever owns the funnel queries. ## Testing - `pnpm typecheck`, targeted `pnpm lint`, full `pnpm test` (2456 passing). - Unit tests cover observer detection (first observation, dedup, per-agent independence, removal, reset), the `record*` event shapes, and the monitor's inline logging (observed vs changed, agent transitions across all agents, agent removal). <details> <summary>Refactor design (reviewer's three-layer shape)</summary> Per the review, the goal was to remove the duplication between the telemetry observers and the state loggers by making transition detection happen once: - **detect**: pure-detection observers report a transition object; no logger or telemetry imports. - **record**: `recordWorkspaceState` / `recordAgentState` in `src/instrumentation/`, telemetry only. - **log**: inline in the monitor, same as every other logging call site. This deletes both `src/workspace/*Logger.ts` files and leaves one tracker per concern. **Observer API decision:** observers return a transition object (workspace → `WorkspaceStateTransition | undefined`; agents → `{ transitions, removed }`) and `WorkspaceMonitor.update()` logs inline and calls `record*`. This was chosen over a constructor callback because `observe()` has a single synchronous caller, so a callback would only hide the side effects and complicate tests. </details> --- 🤖 Generated by Coder Agents.

This was referenced Aug 11, 2026

feat: attach client_session_id to requests and set the CLI session env var #1074

Merged

feat(workspace): log workspace and agent state changes #1075

Merged

EhabY assigned aqandrew Aug 12, 2026

aqandrew added 2 commits August 12, 2026 14:50

docs: remove waffle

f4967de

refactor: rename inner to outputChannel

615ea3b

aqandrew force-pushed the aqandrew/devex-661-session-logger branch from 615ea3b to 445ab75 Compare August 12, 2026 22:00

aqandrew requested review from DanielleMaywood and EhabY August 12, 2026 22:05

EhabY reviewed Aug 13, 2026

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Comment thread src/core/container.ts Outdated

Comment thread src/logging/sessionLogger.ts Outdated

Comment thread src/logging/sessionLogger.ts Outdated

aqandrew force-pushed the aqandrew/devex-661-session-logger branch from 445ab75 to 615ea3b Compare August 13, 2026 18:46

aqandrew added 4 commits August 13, 2026 16:28

chore: rm unused getSessionId function

8e09196

refactor: make SessionLogger's inner a Logger instead of a vscode.Log…

94e9563

…OutputChannel named outputChannel

test: initialize SessionLoggers with createMockLogger

7786bcc

EhabY reviewed Aug 17, 2026

View reviewed changes

EhabY approved these changes Aug 17, 2026

View reviewed changes

aqandrew merged commit 5fbc409 into main Aug 17, 2026
11 checks passed

aqandrew deleted the aqandrew/devex-661-session-logger branch August 17, 2026 20:49

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feat(logging): tag logs with a per-session ID - #1073

feat(logging): tag logs with a per-session ID#1073
aqandrew merged 8 commits into
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aqandrew commented Aug 11, 2026 •

edited by EhabY

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aqandrew commented Aug 11, 2026 •

edited by EhabY

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