Remote Connection (SSH)

Hello all,

I connect usually to one enviornment "dev" daily and then ftp some files to some other enviorment "uat" and then login to "uat" and run some scripts to process these files.

I was thinking to automate the process, where running one script from "dev" will complete all task required to be done on "uat".

sftp part I have already automated. but a bit confused with ssh part.
I am able to login to uat from dev via ssh, but problem is

how to issue a series of command through a script once connected to remote uat?

I checked man pages and forum, but could not locate anything useful.
Any help will be highly appreciated.

Regards,
Rishi

Instead of initiating the process from "dev" i suggest running some script from "uat", that would make things easier. You can use "scp" (man scp) to collect the files from dev and don't have to think about ways to start processes remotely.

If you really need to do it the way you described it for some outside reason you could pack all the commands you want to run remotely into a script there and call this script via ssh (man ssh) using a command like "ssh -l username uat scriptname_to_execute.sh". This will login to machine uat as user "username" and execute the command "scriptname_to_execute.sh", then terminate the connection.

Hope this helps.
bakunin

The reason why I wish to execute process from dev is... its not only uat the file need to be transferred there are many more...sys, rpt, prod etc...

if I go other way round , I end up running scripts from all env.

The idea mentioned of assembling all required commands in one script and fire it remotely is perfectly ok, but I my commands will be dynamic and based on
conditions like files found on dev.

One way to achieve same, I could create a dynamic script first ftp it, and then call via ssh. But I don't want to disturb file enviornment on remote creating temp files.

So we you can suggest any way where we pass bunch of commands to ssh, to be processed on remote will be good.

Thanks for your help.
Rishi

If I did not get it wrong, why can't you put the script in uat and run it remotely from dev? such as
[dev] $ ssh <id>@uat <the script file located in UAT>

Tom

Thanks Tom for your suggestion.
I know it is the only alternative I have as of now.

For this I need to create a dynamic script as per requirement and along with data files I need to sftp them, and finally through ssh invoke it.

Any alternatives where I can invoke a series of command from my local machine one by one, will be preferrable for reasons like local log creation etc.

Any help is welcome.

Regards,
Rishi

You could print some debug statements in the script and redirect the output of the script to some local file. This should work.
i.e. as Tom said:
[dev] $ ssh <id>@uat <the script file located in UAT> >> /whatever/log/file/you/want

The logfile will get created on the local system.

remote logging and executing worked out with all you people effort.

but got one more complication.

The script I am running on remote is interactive one and takes user response "Y/N" type.

In the remote script I read from terminal.

read response < /dev/tty

when I run this piece it throws error saying that"cannot open /dev/tty"
any help to figure out a solution is a welcome.

Thanks in advance.

Regards,
Rishi

why don't you have your script check to see if it's interactive when running on the remote box and, if no, supply a default answer to your query?

or you can just remove the "< /dev/tty" ...

The requirement is such that it need to read response for each processing, hence cannot do away with reading from terminal.

In the script which is executed on remote code looks somewhat like this.

while read line
do

read response < /dev/tty
if [ $response = 'Y' ]; then
.....
fi

done < $datafile

on executing through script it says /dev/tty : cannot open.

Please advise.

Regards,
Rishi

try ...

while read line
do
    echo "Y/N? \c"
    read response
    if [ $response = 'Y' ]; then
    .....
    fi
done < $datafile

while read line
do
    echo "Y/N? \c"
    read response
    if [ $response = 'Y' ]; then
    .....
    fi
done < $datafile

This wont work, because my default input is connected to file, and if I give read in same loop it will read from file instead from terminal.

Therefore I had specifically given

read response < /dev/tty

untested, try...

exec 4<&0
while read line
do
    echo "Y/N? \c" <&4
    read response
    if [ $response = 'Y' ]; then
    .....
    fi
done < $datafile
exec 4<&-