Scripting issue

arunabh_biswas · 09-26-2017, 07:06 AM

Hi LQ experts,

I'm stuck with a single liner bash script. Need your help to fix it.

Let me brief you that what is my expectations from this script.

I need the interfaces configured for a list of servers, their respective IP address and FQDN in a output file. The output should be in the same line.

Here is the script which I'm running it from a jump server having ssh access with pasword.

for i in `cat server-list.txt`;do echo "+++++++++ $i +++++++++";ssh -q $i 'paste <(/sbin/ifconfig -a|egrep -i "eth|bond"|awk '{print $1}') <(/sbin/ifconfig -a|egrep "inet addr"|grep -v "127.0.0.1"|awk '{print $2}'|cut -d ':' -f 2) <(/sbin/ifconfig -a|egrep "inet addr"|grep -v "127.0.0.1"|awk '{print $2}'|cut -d ':' -f 2|xargs -n1 nslookup | grep -v nameserver | cut -f 2 | grep name | cut -f 2 -d "=" | sed 's/ //')';echo "========================="; done > output.txt

Output should look like this -

+++++++++ name of server1 +++++++++
eth1 <ip-of-eth1> <fqdn>
eth3 <ip-of-eth3> <fqdn>
eth4 <ip-of-eth4> <fqdn>
=========================
+++++++++ name of server2 +++++++++
eth1 <ip-of-eth1> <fqdn>
eth3 <ip-of-eth3> <fqdn>
eth4 <ip-of-eth4> <fqdn>
=========================
+++++++++ name of server3 +++++++++
eth1 <ip-of-eth1> <fqdn>
eth2 <ip-of-eth2> <fqdn>
=========================

When I execute it, it gives "paste: /dev/fd/63" No such file or directory".

Thanks in Advance.

Turbocapitalist · 09-26-2017, 08:05 AM

It will help a lot if you post script content between [code] [/code] tags so that the whitespace is preserved.

Then I would suggest that you remove all the references to grep, cut, and sed and keep everything within awk. That will be simpler and faster.

Which distro is this for, including version? Or are there different distros on the remote servers?

ondoho · 09-26-2017, 11:31 AM

this is what it looks like as a real script:

Code:

#!/bin/bash

for i in `cat server-list.txt`;do 
    echo "+++++++++ $i +++++++++"
    ssh -q $i 'paste <(/sbin/ifconfig -a|egrep -i "eth|bond"|awk '{print $1}') \
                     <(/sbin/ifconfig -a|egrep "inet addr"|grep -v "127.0.0.1"|awk '{print $2}'|cut -d ':' -f 2) \
                     <(/sbin/ifconfig -a|egrep "inet addr"|grep -v "127.0.0.1"|awk '{print $2}'|cut -d ':' -f 2|xargs -n1 nslookup | grep -v nameserver | cut -f 2 | grep name | cut -f 2 -d "=" | sed 's/ //')'
    echo "========================="
done > output.txt

...it's still horrible.
you should get rid of about 90% of the pipes and make this into a real shell script, otherwise it will be humanly impossible to troubleshoot
:-(

MadeInGermany · 09-27-2017, 01:13 PM

A single line script?
Here is a multi-line script, that is complicated enough. The major part runs on the local host.

Code:

#!/bin/bash
for i in `cat server-list.txt`
do
  echo "+++++++++ $i +++++++++"
  ssh -qnx "$i" '/sbin/ifconfig' |
  while IFS="" read line
  do
    case $line in
    (lo*)
      if=""
    ;;
    ([a-z]*)
      if="${line%% *}"
      addr=""
    ;;
    (*\ inet*:*)
      addr="${line#* inet*:}"
      addr="${addr# }"
      addr="${addr%%[ /]*}"
      case $addr in
      (127.0.0.1|::1)
        addr=""
      ;;
      esac
    ;;
    esac
    if [ -n "$if" -a -n "$addr" ]
    then
      read ip hst junk < <(getent hosts "$addr")
      echo "$if $addr $hst"
      addr=""
    fi
  done
done

ondoho · 09-28-2017, 03:34 AM

^ is that - a full handout (gasp)?
i hope op has the decency to say thanks.

arunabh_biswas · 10-17-2017, 02:20 AM

m really sorry guys for the delay.....

thanks four your inputs. i've tried those but that didn't work as expected. For this time, i executed the paste commands individually and later merged them... that was really hectic.

i m still looking for a working solution. It is not mandatory to use paste command, anything will work which can put the interface, ip address and fqdn of that ip in the same line with a space or tab between them.

ondoho · 10-17-2017, 02:55 AM

^ only came back to say thanks after it "didn't work"...

MadeInGermany · 10-17-2017, 03:07 AM

What's wrong with my post#4?
Did you run it on the command line?
Do you get an error message? Does it get stuck?
What output do you get, and what do you expect?

KenJackson · 10-17-2017, 11:19 AM

One problem with the original script is the use of single quotes.

Code:

ssh -q $i 'paste <(/sbin/ifconfig -a|egrep -i "eth|bond"|awk '{print $1}') ...

The single quote after awk doesn't start a quoted string, it ends the string which started with paste. And a backslash doesn't seem to protect a single quote, so that's not a solution.

Maybe something like this:

Code:

ssh -q $i 'paste <(/sbin/ifconfig -a | awk -v IGNORECASE=1 "/eth|bond/ \"{print \$1}\"") ...'

Although, MadeInGermany's approach of only running ifconfig once and processing the output on the local machine has a lot of merit. Also notice he used getent instead of nslookup.

TB0ne · 10-17-2017, 11:39 AM

Quote:

Originally Posted by arunabh_biswas

m really sorry guys for the delay.....

thanks four your inputs. i've tried those but that didn't work as expected. For this time, i executed the paste commands individually and later merged them... that was really hectic. i m still looking for a working solution. It is not mandatory to use paste command, anything will work which can put the interface, ip address and fqdn of that ip in the same line with a space or tab between them.

Ok...so why don't you then post what YOU have written/done/tried on your own to get this going??? As you were told before, we WILL NOT write your script for you. Show your own efforts, and we can help you work through problems. If you don't...there is not much we can do for you.