In this hands-on lab, we’re going to write a shell script for connecting to Linux Academy Linux servers from another Linux (or Mac) host, without having to first accept the RSA fingerprint.
Learning Objectives
Successfully complete this lab by achieving the following learning objectives:
- Determine What Options Should Be Used with the `ssh` Command
- View the man page for the
sshcommand, and determine the option to use to disable host key checking.man ssh - The syntax to use is:
ssh -o StrictHostKeyChecking=no user@host
- View the man page for the
- Build a Script from the Required Commands
- Create a
binfolder incloud_user‘s home directory.mkdir bin - Use vim or nano to create the file
lab.shin the newbinfolder.vim bin/lab.sh - Start with the shebang at the top of the file.
#!/bin/bash - Add a line to
sshusing the variable from above and taking the first parameter as the host address.ssh -o StrictHostKeyChecking=no $login_user@$1 - Add a line to set a variable for the login user.
login_user=cloud_user - Add two lines to make sure that that the first variable is not null and close the script.
if [ -n $1 ]fi The completed script should look like this
#!/bin/bash login_user=cloud_user if [ -n $1 ] then ssh -o StrictHostKeyChecking=no $login_user@$1 fi- Then save the file by running:
:wq!
- Create a
- Execute and Verify the Script
- Save the file, and make it executable.
chmod u+x bin/lab.sh - Run the script, passing
10.0.1.10as the first parameter to be assigned to$1../bin/lab.sh 10.0.1.10 - Once prompted input the
cloud_user‘s password.
- Save the file, and make it executable.
- Add the New `bin` Directory to the `PATH` Variable
- Append to the
.bashrcfile incloud_user‘s home directory to add the newbinfolder to thePATHenvironment variable.echo 'PATH="$HOME/bin:$PATH"' >> .bashrc - Source
.bashrcto pick up the change.source .bashrc - Verify that you can run
lab.shwithout specifying the path to the script.lab.sh 10.0.1.10
- Append to the
