Status callback for exec is never called when stdin closes

Is it possible to close stdin for Exec without closing ws connection?

StatusStream is not received if WS connection is closed as well as additional data on stdout, stderr streams is lost.

You could try sending an explicit control-D character across the stream. That should close the stream in the application.

@brendandburns

@brendandburns neat, that does work indeed, but only when tty is also attached.

With tty I am not able to correctly receive binary data for exec command.

tar xf - -C /tmp
tar: Refusing to read archive contents from terminal (missing -f option?)
tar: Error is not recoverable: exiting now
{
  metadata: {},
  status: 'Failure',
  message: 'command terminated with non-zero exit code: Error executing in Docker Container: 2',
  reason: 'NonZeroExitCode',
  details: { causes: [ [Object] ] }
}

Makes sense ctrl-d is a terminal character after all.

This error is coming from the tar command itself. I'm not sure why that's happening, but I don't think it's related to this library.

@brendandburns

@brendandburns you are correct it will be related to tty itself, but the fact with result is as kubectl exec is not behaving like that when stdin is closed. I was digging into kubectl exec and I figured out it's using SPDY and multiple streams for different io instead of single websocket connection.

I think issue could be solved with #411 or maybe there is way for ws protocol to close streams some other way.

kubernetes/kubernetes#89899

I'm obviously not certain, but I think tar is giving up before stdin is even considered. I'm uncertain about the difference between tar xf - ... vs tar -x -f - but you may be since that is referenced in the error message.

It does not matter what executable I try to run, even cat breaks up in similiar manner as if you try to paste binary data trough regular terminal. I believe I would have to somehow escape the data so the terminal could recognize 0x04 as a byte and as a ctrl-d. I am not sure if thats possible (I was not able to find anything about that), but could also solve the issue.

@mochja

Did you find out something @mochja? I'm trying to upload some file with exec to a pod and I experience the same you do.

@bankyadam

@bankyadam I did not, I think there are only two proper ways to handle this:

Use SPDY protocol instead of WS
Implement closing streams into WS protocol itself

I was experimenting by removing following lines

javascript/src/web-socket-handler.ts

Lines 68 to 70 in 932c2fb

    
           stdin.on('end', () => { 
        
               ws.close(); 
        
           });

and if I am remembering correctly it was somewhat working.

Issues go stale after 90d of inactivity.
Mark the issue as fresh with /remove-lifecycle stale.
Stale issues rot after an additional 30d of inactivity and eventually close.

If this issue is safe to close now please do so with /close.

Send feedback to sig-testing, kubernetes/test-infra and/or fejta.
/lifecycle stale

Stale issues rot after 30d of inactivity.
Mark the issue as fresh with /remove-lifecycle rotten.
Rotten issues close after an additional 30d of inactivity.

If this issue is safe to close now please do so with /close.

Send feedback to sig-testing, kubernetes/test-infra and/or fejta.
/lifecycle rotten

Rotten issues close after 30d of inactivity.
Reopen the issue with /reopen.
Mark the issue as fresh with /remove-lifecycle rotten.

Send feedback to sig-testing, kubernetes/test-infra and/or fejta.
/close

@fejta-bot

@fejta-bot: Closing this issue.

Details

In response to this:

Rotten issues close after 30d of inactivity.
Reopen the issue with /reopen.
Mark the issue as fresh with /remove-lifecycle rotten.

Send feedback to sig-testing, kubernetes/test-infra and/or fejta.
/close

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

Navigation Menu

Repository navigation

Status callback for exec is never called when stdin closes #465

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Status callback for exec is never called when stdin closes #465

Description

Activity

brendandburns commented on Jun 13, 2020

mochja commented on Jun 14, 2020

brendandburns commented on Jun 17, 2020

mochja commented on Jun 17, 2020

brendandburns commented on Jun 19, 2020

mochja commented on Jun 19, 2020

bankyadam commented on Aug 6, 2020

mochja commented on Aug 6, 2020

fejta-bot commented on Nov 4, 2020

fejta-bot commented on Dec 4, 2020

fejta-bot commented on Jan 3, 2021

k8s-ci-robot commented on Jan 3, 2021

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions