At this point in time I need a nifty little tool to configure some ports on network devices. But the challenge is that the ports differ from device to device.
In order to do this I have to create a script to harvest data out of the network. Output files will be parsed through combination of bash/grep/awk.
The main thing I could not get my head around was how to read a file and hand data over to a spawned ssh session.
As a proof of concept I created a file with commands to execute on another node. And also a tiny tcl script to open a ssh session, logon, read the commands file, close the ssh session.
Contents of my commands.txt file is below, nothing fancy just to get the proof of concept.
du -h
uname
Open a file to read , read into $file_data, close the file.
set fp [open "commands.txt" r]
set file_data [ read $fp ]
close $fp
Split the $file_data into usable chunks.
set dataln [ split $file_data "\n"]
Walkthrough the $dataln and give the data to the ssh session.
# loop through $dataln and store data in $line
foreach line $dataln {
# just an obvisous expectation.
expect ">" {
# send the $line to ssh session..
send "$line\r"
}
}
Complete test.tcl (awesome name right 😉 )
#!/usr/bin/expect
set nethost [lindex $argv 0]
set netuser [lindex $argv 1]
set netpass [lindex $argv 2]
# -- file open magic here
set fp [open "commands.txt" r]
set file_data [ read $fp ]
close $fp
# -- file_data read here , split to dataln
set dataln [ split $file_data"\n"]
spawn ssh "$netuser@$nethost"
expect "assword"{
send "$netpass\r"
}
# -- walk through $dataln
foreach line $dataln{
expect ">"{
send "$line\r"
}
}
expect ">"{
send "exit\r"
}
# in case exit fails...
interact
This is the final result;
$ ./test.tcl DS 1user SecRet
spawn ssh 1user@DS
1user@ds's password:
BusyBox xxxxxxxxxxx
Enter 'help' for a list of built-in commands.
DiskStation> du -h
8.0K ./.ssh
--//output omited for brevity//--
408.0K ./script-test
496.0K .
DiskStation> uname
Linux
DiskStation> exit
Connection to ds closed.
As you can imagine a little work still has to be done. Like creating a several files with configuration. While executing the bash/tcl wrapper handing over the config file as an argument. But that shouldn’t be to hard. Maybe something thing like this; (of course some sanity check have to be build in)
ls *config.txt |
while read file
do
echo "./wrapper.tcl ${file%_*} user pass $file"
done
Network Ninja 