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Kyle Carberry
fee5cc5e5b
Fixes https://github.com/coder/internal/issues/1371 ## Root causes Two independent races cause this test to flake at ~2–3/1000: ### 1. Title-generation requests racing with the streaming request counter `maybeGenerateChatTitle` fires in a `context.WithoutCancel` goroutine (line 2130) and makes a **non-streaming** request to the mock OpenAI handler. The test handler was not filtering by request type, so these title requests incremented the `requestCount` atomic — throwing off the coordination logic that uses `requestCount == 1` to identify the first streaming request and hold it open until shutdown. **Fix:** Guard the test handler to return a canned response for non-streaming requests before touching `requestCount`. ### 2. Phantom acquire: `AcquireChat` commits in Postgres but Go sees `context.Canceled` During `Close()`, the main loop's `select` can randomly pick `acquireTicker.C` over `ctx.Done()` (Go spec: when multiple cases are ready, one is chosen uniformly at random). This calls `processOnce(ctx)` with an already-canceled context. In the pq driver, `QueryContext` does **not** check `ctx.Err()` up front. Instead it calls `watchCancel(ctx)` which spawns a goroutine monitoring `ctx.Done()`, then sends the query on the existing connection. When `ctx` is already canceled, a race ensues: - **pq's watchCancel goroutine** immediately sees `<-done`, opens a *new* TCP connection to Postgres, and sends a cancel request. - **The query** is sent concurrently on the existing connection. Because the `AcquireChat` UPDATE is fast (sub-millisecond, single row with `SKIP LOCKED`), it often commits before the cancel arrives via the second connection. Meanwhile in `database/sql`, `initContextClose` spawns an `awaitDone` goroutine that fires immediately (context is already canceled), stores `contextDone`, and calls `rs.close(ctx.Err())` — which races with `Row.Scan` → `rows.Next()`. If `awaitDone` wins, `Next()` sees `contextDone` is set and returns false, causing Scan to return `context.Canceled` (or `ErrNoRows`). **Result:** Postgres committed the UPDATE (chat is now `running` with serverA's worker ID), but Go sees an error and never spawns a goroutine to process it. The chat is stuck as `running` with no worker. If the previous `processChat` cleanup already set the chat back to `pending`, this phantom acquire flips it back to `running` — which is exactly what the debug logs showed: after `Close()` returns, the DB shows `status=running` with serverA's worker ID. **Fix:** Three guards in `processOnce`: 1. Early `ctx.Err()` check — catches the common case where `select` picked the ticker after cancellation. 2. `context.WithoutCancel(ctx)` for `AcquireChat` — prevents the pq `watchCancel` race entirely, ensuring the driver sees the query result if Postgres executed it. 3. Post-acquire `ctx.Err()` check — if the context was canceled while `AcquireChat` ran (or between the early check and the call), immediately release the chat back to `pending`. ## Verification Passes 2000/2000 iterations (previously flaked at ~2–3/1000): ``` go test -run "TestCloseDuringShutdownContextCanceledShouldRetryOnNewReplica" \ -count=2000 -timeout 1800s -failfast ./coderd/chatd/ ```
Coder enables organizations to set up development environments in their public or private cloud infrastructure. Cloud development environments are defined with Terraform, connected through a secure high-speed Wireguard® tunnel, and automatically shut down when not used to save on costs. Coder gives engineering teams the flexibility to use the cloud for workloads most beneficial to them.
- Define cloud development environments in Terraform
- EC2 VMs, Kubernetes Pods, Docker Containers, etc.
- Automatically shutdown idle resources to save on costs
- Onboard developers in seconds instead of days
Quickstart
The most convenient way to try Coder is to install it on your local machine and experiment with provisioning cloud development environments using Docker (works on Linux, macOS, and Windows).
# First, install Coder
curl -L https://coder.com/install.sh | sh
# Start the Coder server (caches data in ~/.cache/coder)
coder server
# Navigate to http://localhost:3000 to create your initial user,
# create a Docker template and provision a workspace
Install
The easiest way to install Coder is to use our
install script for Linux
and macOS. For Windows, use the latest ..._installer.exe file from GitHub
Releases.
curl -L https://coder.com/install.sh | sh
You can run the install script with --dry-run to see the commands that will be used to install without executing them. Run the install script with --help for additional flags.
See install for additional methods.
Once installed, you can start a production deployment with a single command:
# Automatically sets up an external access URL on *.try.coder.app
coder server
# Requires a PostgreSQL instance (version 13 or higher) and external access URL
coder server --postgres-url <url> --access-url <url>
Use coder --help to get a list of flags and environment variables. Use our install guides for a complete walkthrough.
Documentation
Browse our docs here or visit a specific section below:
- Templates: Templates are written in Terraform and describe the infrastructure for workspaces
- Workspaces: Workspaces contain the IDEs, dependencies, and configuration information needed for software development
- IDEs: Connect your existing editor to a workspace
- Administration: Learn how to operate Coder
- Premium: Learn about our paid features built for large teams
Support
Feel free to open an issue if you have questions, run into bugs, or have a feature request.
Join our Discord to provide feedback on in-progress features and chat with the community using Coder!
Integrations
We are always working on new integrations. Please feel free to open an issue and ask for an integration. Contributions are welcome in any official or community repositories.
Official
- VS Code Extension: Open any Coder workspace in VS Code with a single click
- JetBrains Toolbox Plugin: Open any Coder workspace from JetBrains Toolbox with a single click
- JetBrains Gateway Plugin: Open any Coder workspace in JetBrains Gateway with a single click
- Dev Container Builder: Build development environments using
devcontainer.jsonon Docker, Kubernetes, and OpenShift - Coder Registry: Build and extend development environments with common use-cases
- Kubernetes Log Stream: Stream Kubernetes Pod events to the Coder startup logs
- Self-Hosted VS Code Extension Marketplace: A private extension marketplace that works in restricted or airgapped networks integrating with code-server.
- Setup Coder: An action to setup coder CLI in GitHub workflows.
Community
- Provision Coder with Terraform: Provision Coder on Google GKE, Azure AKS, AWS EKS, DigitalOcean DOKS, IBMCloud K8s, OVHCloud K8s, and Scaleway K8s Kapsule with Terraform
- Coder Template GitHub Action: A GitHub Action that updates Coder templates
Contributing
We are always happy to see new contributors to Coder. If you are new to the Coder codebase, we have a guide on how to get started. We'd love to see your contributions!
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Apply here if you're interested in joining our team.