Bash - here document on RHEL 6.8 and 6.9 servers aren't working Post: 303040553

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Top Forums UNIX for Beginners Questions & Answers Bash - here document on RHEL 6.8 and 6.9 servers aren't working Post 303040553 by greavette on Thursday 31st of October 2019 11:50:49 AM

10-31-2019

Registered User

Bash - here document on RHEL 6.8 and 6.9 servers aren't working

H Forum,

I was thankful in getting help from this post that allowed me to connect to multiple severs at once using here documents to gather data into variables. But I've discovered that the same bash command that works on my RHEL 7 servers do not work on RHEL 6? What's strange about my problem is that I'm not getting an error either. The problem is that the variables return empty when I try the following code on RHEL 6.8 or 6.9 servers we manage:

Code:

IFS=$'\t' read FLAVOUR HOSTNAME ACTIVE_KERNEL INACTIVE_KERNEL UPTIME <<- EOFREAD
        $ssh -qo StrictHostKeyChecking=no -o ConnectTimeout=1 user@$InputIP sudo -u user sh -s <<- EOFSSH | tr $'\n' $'\t'
        exec bash
        cat /etc/redhat-release 2>/dev/null || lsb_release -a 2>/dev/null | grep Description | cut -f2
        awk -F= '/^NAME/{print $2}' /etc/os-release 2>/dev/null || grep Red |cat /etc/redhat-release 2>/dev/null || lsb_release -a 2>/dev/null | grep Description | cut -f2
        hostname
        uname -r
        rpm -qa | grep '^kernel-[0-9]' |grep -vE `uname -r` | paste -sd \; || echo "Can't List Ubuntu Kernels"
        uptime | cut -d "," -f1
        exit
EOFSSH
        )
EOFREAD

I've thought of adding in the ability to determine if my server is RHEL 6 or 7 using code like the following:

python -mplatform | grep -qi red &&

but even if I could determine RHEL version I'm still not sure why my RHEL 6 servers do not return variable data back. I've tested this above code connecting to just one server to try and triage the issue. No errors are returned. the variable fields are just empty. Whereas on my RHEL 7 servers I return back variables with no issue. Could it be that how I use Here Documents just doesn't work with RHEL 6 servers? has anyone seen this before?

I've also tested connecting to a RHEL 6 server multiple times to get the data I need. what I mean by this is instead of connecting to a RHEL 6 server once and collecting data I've tested connecting to a RHEL 6 for each command I need so connecting multiple times and there are no issues with the above commands I'm issuing.

Perhaps I'll just need to identify RHEL 6 servers and gather their data differently than I do for RHEL 7 severs but before I do that I thought I would check this forum for any advice first.

Thank you.

greavette

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LEARN ABOUT CENTOS

subscription-manager-gui

subscription-manager-gui(8)				       Subscription Manager				       subscription-manager-gui(8)

NAME

       subscription-manager-gui - Launches the UI client of the Subscription Manager.

SYNOPSIS

       subscription-manager-gui [--register]

DESCRIPTION

       subscription-manager-gui  opens	the  local client tool to manage subscriptions and installed products on Red Hat Enterprise Linux systems.
       The same tasks that can be performed by invoking subscription-manager can be performed in the GUI, including  registering  systems  with  a
       subscription management service, applying and removing subscriptions, and viewing the subscription status of installed products.

       The Subscription Manager UI can also be opened by selecting the Red Hat Subscription Manager item from the Applications > System Tools menu
       in RHEL 5.x or the System > Administration menu in RHEL 6.x.

OPTIONS

       --register
	      If a system has not yet been registered, then the GUI registration page can be opened immediately, as the Subscription  Manager  GUI
	      comes up. This is only relevant for unregistered systems; if this is used after a system is registered, the option is ignored.

REFERENCES

       For  procedures	and  tasks that can be performed in the Subscription Manager UI, check the Gnome help files (by pressing <F1>) or refer to
       the RHEL Subscription  Management  Guide  at  <https://access.redhat.com/knowledge/docs/en-US/Red_Hat_Subscription_Management/1.0/html/Sub-
       scription_Management_Guide/index.html>.

ASSOCIATED FILES

	      * /usr/sbin/subscription-manager-gui

	      * /usr/sbin/subscription-manager

	      * /etc/rhsm/rhsm.conf

BUGS

       This  client  is  part of Red Hat Subscription Manager. To file bugs against this client, go to https://bugzilla.redhat.com, and select Red
       Hat > Red Hat Enterprise Linux > subscription-manager.

AUTHORS

       Deon Lackey, <dlackey@redhat.com>.

COPYRIGHT

       Copyright (c) 2010-2012 Red Hat, Inc. This is licensed under the GNU General Public License, version 2 (GPLv2). A copy of this  license	is
       available at http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.

version 1.2							 December 18, 2012				       subscription-manager-gui(8)