1st May 2014, 2 min read

Defeating Annoying Timeout in OpenShift SSH Access

Original post is here eklausmeier.goip.de/blog/2014/05-01-defeating-annoying-timeout-in-openshift-ssh-access.

One simple way to get rid of the very short timeout in shell access to OpenShift is to unset the TMOUT environment variable:

unset TMOUT

Before I knew that I used an Expect script. Below Expect script defeats the annoying timeout by sending some text every 60 seconds.

#!/usr/bin/expect
# Defeat OpenShift timeout in ssh access

set user        <your user>
set domain      <your domain>
set timeout -1

spawn ssh -i $::env(HOME)/.ssh/id_rsa_openshift $user@$domain.rhcloud.com
expect "\[$domain.rhcloud.com $user\]\\>"

send "set -o vi\n"
send "alias l='ls -aCF'; alias ll='ls -alF'; alias ..='cd ..'; alias ...='cd ../..'; alias p='ps -fu \$UID'; alias li=less; alias v=vi\n"
send "unset TMOUT\n"

interact timeout 60 {send "# Still alive\n"}

Noting that OpenShift doesn't cost you a dime, you get a quite powerful machine. Below is the CPU configuration.

$ cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 45
model name      : Intel(R) Xeon(R) CPU E5-2650 0 @ 2.00GHz
stepping        : 7
cpu MHz         : 1800.000
cache size      : 20480 KB
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu de tsc msr pae cx8 sep cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm rep_good aperfmperf unfair_spinlock pni pclmulqdq ssse3 cx16 pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes hypervisor lahf_lm arat epb xsaveopt pln pts dts
bogomips        : 3600.00
clflush size    : 64
cache_alignment : 64
address sizes   : 46 bits physical, 48 bits virtual
power management:

processor       : 1
vendor_id       : GenuineIntel
cpu family      : 6
model           : 45
model name      : Intel(R) Xeon(R) CPU E5-2650 0 @ 2.00GHz
stepping        : 7
cpu MHz         : 1800.000
cache size      : 20480 KB
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu de tsc msr pae cx8 sep cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm rep_good aperfmperf unfair_spinlock pni pclmulqdq ssse3 cx16 pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes hypervisor lahf_lm arat epb xsaveopt pln pts dts
bogomips        : 3600.00
clflush size    : 64
cache_alignment : 64
address sizes   : 46 bits physical, 48 bits virtual
power management:

This is the operating system:

$ lsb_release -a 
LSB Version:    :base-4.0-amd64:base-4.0-noarch:core-4.0-amd64:core-4.0-noarch:graphics-4.0-amd64:graphics-4.0-noarch:printing-4.0-amd64:printing-4.0-noarch
Distributor ID: RedHatEnterpriseServer
Description:    Red Hat Enterprise Linux Server release 6.5 (Santiago)
Release:        6.5
Codename:       Santiago

This is the kernel version:

$ uname -a
Linux ex-std-node258.prod.rhcloud.com 2.6.32-431.11.2.el6.bz844450.x86_64 #1 SMP Mon Mar 31 11:32:14 EDT 2014 x86_64 x86_64 x86_64 GNU/Linux

Pinging the server reveals that the OpenShift servers are actually hosted by Amazon Web Services.

$ ping -c2 <domain>.rhcloud.com
PING ec2-54-224-157-36.compute-1.amazonaws.com (54.224.157.36) 56(84) bytes of data.
64 bytes from ec2-54-224-157-36.compute-1.amazonaws.com (54.224.157.36): icmp_seq=1 ttl=38 time=174 ms
64 bytes from ec2-54-224-157-36.compute-1.amazonaws.com (54.224.157.36): icmp_seq=2 ttl=38 time=172 ms