sysctlFSFileMax not using fs.file-max

[gyliu513]

Is this a request for help? (If yes, you should use our troubleshooting guide and community support channels, see https://kubernetes.io/docs/tasks/debug-application-cluster/troubleshooting/.):

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---

Is this a BUG REPORT or FEATURE REQUEST? (choose one):

NGINX Ingress controller version:

I was using ingress 0.9.0.

I updated the initContainer in ingress controller by adding sysctl -w fs.file-max=1608170 as following:

  initContainers:
      - command:
        - sh
        - -c
        - sysctl -w fs.file-max=1608170; sysctl -w net.core.somaxconn=32768; sysctl
          -w net.ipv4.ip_local_port_range="1024 65535"

And restart the ingress controller, but in the log, I found that the file max was still 65536.

[root@gyliu-icp-1 ~]# cat ingress2.log | grep "maximum number of open file descriptors"
I0208 06:01:29.819389       7 nginx.go:557] maximum number of open file descriptors : 65536

Related source code here https://github.com/kubernetes/ingress-nginx/blob/nginx-0.9.0/internal/ingress/controller/nginx.go#L559:60

/cc @aledbf any comments for this? Thanks!

Kubernetes version (use kubectl version):

Environment:

• Cloud provider or hardware configuration:
• OS (e.g. from /etc/os-release):
• Kernel (e.g. uname -a):
• Install tools:
• Others:

What happened:

What you expected to happen:

How to reproduce it (as minimally and precisely as possible):

Anything else we need to know:

[gyliu513]

I found that we are now using following logic to get maximum number of open file descriptors, is it possible to update it via sysctl command?

func sysctlFSFileMax() int {
	var rLimit syscall.Rlimit
	err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rLimit)
	if err != nil {
		glog.Errorf("unexpected error reading system maximum number of open file descriptors (RLIMIT_NOFILE): %v", err)
		// returning 0 means don't render the value
		return 0
	}
	return int(rLimit.Max)
}

[aledbf]

I found that we are now using following logic to get maximum number of open file descriptors, is it possible to update it via sysctl command?

What do you mean? We read the value using the RLIMIT_NOFILE syscall (same thing than using sysctl)

[gyliu513]

After talk with @aledbf , this PR ec67f83 made the update, will try to use original logic to see if it works.

[luckyfengyong]

@gyliu513 Do you run initContainer with privileged? fs.file-max is the OS level configuration. You could check in the host or inside ingress controller container, whether the configuration of fs.file-max takes effect.

[gyliu513]

I did some test with revert ec67f83 , ingress works fine and can get fs.file-max.

For my case, I set the fs.file-max=90000, and ingress controller can get this value well I0208 16:04:53.698915 7 nginx.go:559] maximum number of open file descriptors : 90000

Will create a PR to revert ec67f83 @aledbf

[aledbf]

Closing. Fixed in #2050