sandbox: timeout runsc commands

The current mechanism for forcing a process to die ater a timeout is not
sufficient. This change fixes issues that were causing processes to run
forever on the sandbox.

- Gracefully terminate processes before we kill them inside of our
gVisor process. This helps capture valuable debug output for the user.

- Return a friendlier error when our run context times out on the
playground.

- Add a test that timeouts are handled gracefully.

- Reduce concurrent goroutines in our sandbox run handler by replacing
goroutine copy functions with a custom writer (limitedWriter) that
returns an error if too much output is returned, halting the program.

- Custom writers (limitedWriter, switchWriter) also fix timing errors
when calling Wait() too soon on a Command, before we have read all of
the data. It also fixes a different error from trying to read data after
a program has terminated.

- Remove goroutine from startContainer, and use a ticker + context
timeout for synchronization.

Updates golang/go#25224
Updates golang/go#38343

Change-Id: Ie9d65220e5c4f39272ea70b45c4b472bcd7069bb
Reviewed-on: https://go-review.googlesource.com/c/playground/+/227652
Run-TryBot: Alexander Rakoczy <alex@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
5 files changed
tree: 7f25616f7c8488f95f3d409f1aa51b3a67db32be
  1. .gitignore
  2. AUTHORS
  3. CONTRIBUTING.md
  4. CONTRIBUTORS
  5. Dockerfile
  6. LICENSE
  7. Makefile
  8. PATENTS
  9. README.md
  10. app.yaml
  11. cache.go
  12. client.go
  13. cmd/
  14. codereview.cfg
  15. deploy/
  16. edit.go
  17. edit.html
  18. enable-fake-time.patch
  19. examples/
  20. fake_fs.lst
  21. fmt.go
  22. fmt_test.go
  23. go.mod
  24. go.sum
  25. internal/
  26. logger.go
  27. main.go
  28. play.go
  29. play_test.go
  30. sandbox.go
  31. sandbox/
  32. server.go
  33. server_test.go
  34. share.go
  35. static/
  36. store.go
  37. tests.go
  38. txtar.go
  39. txtar_test.go
  40. vet.go
README.md

playground

This subrepository holds the source for the Go playground: https://play.golang.org/

Building

# build the image
docker build -t playground .

Running

docker run --name=play --rm -p 8080:8080 golang/playground &
# run some Go code
cat /path/to/code.go | go run client.go | curl -s --upload-file - localhost:8080/compile

Deployment

Deployment Triggers

Playground releases automatically triggered when new Go repository tags are pushed to GitHub, or when master is pushed on the playground repository.

For details, see deploy/go_trigger.json, deploy/playground_trigger.json, and deploy/deploy.json.

After making changes to trigger configuration, update configuration by running the following Make target:

make update-cloudbuild-trigger

Deploy via Cloud Build

The Cloud Build configuration will always build and deploy with the latest supported release of Go.

gcloud builds submit --config deploy/deploy.json .

Deploy via gcloud app deploy

Building the playground Docker container takes more than the default 10 minute time limit of cloud build, so increase its timeout first (note, app/cloud_build_timeout is a global configuration value):

gcloud config set app/cloud_build_timeout 1200  # 20 mins

Alternatively, to avoid Cloud Build and build locally:

make docker
docker tag golang/playground:latest gcr.io/golang-org/playground:latest
docker push gcr.io/golang-org/playground:latest
gcloud --project=golang-org --account=you@google.com app deploy app.yaml --image-url=gcr.io/golang-org/playground:latest

Then:

gcloud --project=golang-org --account=you@google.com app deploy app.yaml

Contributing

To submit changes to this repository, see https://golang.org/doc/contribute.html.