kubectl command disconnects after few minutes of idle time

6/5/2018

We noticed when we exec -it to connect into a pod, after certain idle time the connection get destroyed. Is there any option to leave the connection open longer?

I see there is an open PR, but wondering if there is any workaround for this issue.

-- user1595858
kubectl
kubernetes

1 Answer

6/5/2018

The short answer is no. And that's why:

Enabling TCP keepalive for console connections

TCP keepalive is a TCP option that causes packets to be exchanged over a connection even if there is no traffic to transport. It should be enabled on both ends of the connection. TCP keepalive must be enabled at the operating-system level and by the application/program opening TCP connections.

On Linux, edit the "/etc/sysctl.conf" file and add these lines:

net.ipv4.tcp_keepalive_time = 200
net.ipv4.tcp_keepalive_probes = 9
net.ipv4.tcp_keepalive_intvl = 50

(feel free to adapt the values as you see fit). When done editing, you must make the new values known to the kernel:

# sysctl --load=/etc/sysctl.conf

Custom Configuration of TCP Socket Keep-Alive Timeouts

Default values for these properties is:

tcp_keepalive_time = 7200 seconds
tcp_keepalive_probes = 9
tcp_keepalive_intvl = 75 seconds

The other possible way is to start some kind of proxy server on the client side and connect to Kubernetes apiserver through it. I haven’t tested it myself and it could be tricky, but here is an example of how to enable keepalives to backend for Nginx.

-- VAS
Source: StackOverflow