Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Notify service manager when start up is completed #1148

Open
wants to merge 1 commit into
base: develop
Choose a base branch
from

Conversation

one-d-wide
Copy link

Currently there is no way to notify service manager when yggdrasil start up process is truly completed, i.e its TUN interface and admin API endpoints are up and running. This makes naive services, set to depend on the yggdrasil network, periodically crash on startup, requiring sub-optimal complications for trivial tasks.

This PR solves the issue by notifying the service manager after TUN interface and admin sockets are ready. Systemd support is implemented by sending a short READY=1 message to a UNIX datagram socket defined in a NOTIFY_SOCKET environment variable, see sd_notify(3).

Changes

  • cmd/yggdrasil/main.go - Added invocation for notifyStartupCompleted right after TUN interface and admin sockets are set up.
  • cmd/yggdrasil/notify_startup_*.go - Added notifyStartupCompleted function handling the process on linux and immediately returning on other platforms.
  • contrib/systemd/yggdrasil.service* - Service Type is changed to notify, added a comment about NotifyAccess property.

@neilalexander
Copy link
Member

Not intentionally ignoring this PR BTW, but it has a knock-on effect to quite a few packages, so probably not for a patch release.

if _, err = notifyStartupCompleted(); err != nil {
log.Warnln("Error while sending start up notification:", err)
}

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

There is no guarantee at this point (in the main goroutine) that startup tasks in other goroutines have been finished, since they don't synchronise.

So I think you are just racing against tun(4) setup just like -chuser is already racing against the control socket setup over at #927 (comment)

@@ -272,6 +272,10 @@ func main() {
}
}

if _, err = notifyStartupCompleted(); err != nil {
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The first bool return value is never used, so why have it at all?

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

3 participants