Polaris exits immediately when run in a container
pcgeek86 opened this issue · 5 comments
Problem Statement
When I run Start-Polaris
inside a container, the container exits immediately because the command is asynchronous. I tried adding a Start-Sleep -Seconds 100
command after Start-Polaris
, but this caused the route handlers to block, so the web server was non-responsive.
Proposed Solution
Add a -Wait
parameter to the Start-Polaris
command, to block script execution and force the command to run synchronously.
I found a container example here, which also uses the Start-Sleep
approach, but as mentioned in the OP, that causes the process to block.
https://github.com/PowerShell/Polaris/pull/145/files#diff-f4d1fe67442cfa70093f78fb980a58c4
Hi @pcgeek86,
Thanks for submitting the issue! We do have a method better than sleep but it isn't documented very well.
Polaris uses a callback bridge to fire events so you can hold a process open using Wait-Event
like this:
while ($Polaris.Listener.IsListening) {
Wait-Event callbackeventbridge.callbackcomplete
}
This is a fairly common scenario, not specific to containers so it might be a good idea to add a switch or something to the Start-Polaris command.
I'm not sure what a good name for the switch would be though... Start-Polaris -Wait
or Start-Polaris -HoldThreadOpen
or all sound to me like 'Micah sucks at naming things!'
Thanks Micah! I will give that a shot.
Considering that Start-Process
has a -Wait
parameter, this seems like a good convention to follow!
@TylerLeonhardt - What do you think about adding a -Wait
parameter?
@pcgeek86 I haven't tested to see if this still works. But, here is a repo from when I was playing with running Polaris in a container.