Set min value of maxOpenFiles as 64000

[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/.):

What keywords did you search in NGINX Ingress controller issues before filing this one? (If you have found any duplicates, you should instead reply there.):

---

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

We are now setting the default value of maxOpenFiles as 1024 which is a bit small, as it will sometimes cause ingress cannot start.

Even though we can set fs.file-max to a large value, but sometimes setting a too big value will cause nginx report error setrlimit(RLIMIT_NOFILE, 98976) failed (1: Operation not permitted).

So how about setting the minimum value as 64000 and this can fulfill most cases. If customer have large fs.file-max, they can enlarge ulimit -n to increase the value of rlimit.

Comments? @aledbf

NGINX Ingress controller version:
0.9.0

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:

[aledbf]

@gyliu513 we cannot do that because if you set a higher value than the configured for the pod the controller will never start.

[chestack]

my env: 128 cpu cores

nginx.conf:

worker_processes: 128;
worker_rlimit_nofile: 1024;
events {
    worker_connections  16384;
}

nginx error: accept4() failed (24 too many open files)

default value minimum 1024 is not enough for 128 worker_processes