Bash script to monitor system service

This bash script runs and checks to see if a service like httpd, or mysql is running and alerts if it is not.

Script Usage

servicemonitor.sh httpd mariadb

Where httpd and mariadb are the services you want to monitor/check.

Setup Script

Create servicemonitor.sh file and paste the following contents in.

#!/bin/bash

timeHour=date +%H # date/time just shows the hour
quietHour="02" # If it is this hour, then exit program, useful if services are expected to go down during a particular time for maintenance
if ( echo ${timeHour} | grep ${quietHour}); then
echo "Is during quiet time. Quiting."
exit
fi

function ALERT {
msg="~/teams.sh -b" # Sends a message to Microsoft Teams channel. Needs the teams.sh script in the users home directory.
${msg} "$1"
}
function SERVICECHECK {
serviceName="${1}"
if (systemctl status ${serviceName} | grep Active | grep inactive); then
ALERT "ERROR: $(hostname) - ${serviceName} - ${0} is inactive"
echo "ERROR: ${serviceName} is inactive!"
else
echo "Running!"
fi
}
for i in $@
do
echo Checking ${i}
SERVICECHECK ${i}
done

Note the teams.sh script that is called is another script that is called that sends an alert to Microsoft Teams. Is not needed for this script to run, but allows for remote alerting.

Save file and make it executable

chmod +x servicemonitor.sh

Add script to crontab (Optional)

crontab -e

The following runs the script every 5 minutes. Can change the 5 to 1 to run every minute. Change httpd and mariadb to the service you want to monitor.

*/5 * * * * /home/UserName/servicemonitor.sh httpd mariadb

BASH Script to add new SFTP user and setup permissions

This script adds a new SFTP user with only sftp access.  Refer to this post on setting up a SFTP server.

Download script

wget www.incredigeek.com/home/downloads/scripts/sftpUserAdd.sh

Make executable

chmod +x sftpUserAdd.sh

Run with the new user you want to create.

./sftpUserAdd.sh sftpUsername

You may need to edit the script and modify the location parameters.

#!/bin/bash
# Automatically setup and add SFTP user
# Script creates new user and setups permissions
newUser=$1
sftpDir="/sftp/"
if grep -q ${newUser} /etc/passwd ;then
echo ${newUser} Already exsists. Aborting!
exit 1
else
mkdir -p ${sftpDir}/${newUser}/files
useradd -g sftpusers -d ${sftpDir}/${newUser}/files -s /sbin/nologin ${newUser}
passwd ${newUser}
chown ${newUser}:sftpusers /sftp/CareMark/files
fi

LibreNMS bulk delete

There is a php script in /opt/librenms/ that lets you delete a host from the command line.

sudo /opt/librenms/delhost.php 192.168.1.20

Replace 192.168.1.20 with the hostname/ip address of the host you want to delete.

Delete Multiple Hosts

First you’ll need to get a list of devices you want to remove.  You can do this by viewing the devices in the LibreNMS MySQL database;

Example:

$ mysql -u librenms -p librenms
MariaDB [librenms]> select hostname from devices;
+----------------------------------------+
| hostname |
+----------------------------------------+
| 192.168.88.1 |
| 192.168.1.20 |
| 192.168.1.12 |
| 192.168.88.5 |
4 rows in set (0.00 sec)
MariaDB [librenms]> exit

Put all the IP addresses you want to remove into a file and run the following for loop.  Replace “remove_ip.lst” with the name of your ip list file.

for i in `cat ~/remove_ip.lst`; do sudo /opt/librenms/delhost.php $i; done

Upload ssh key to multiple servers automatically

Here is a quick script I created to automate copying a ssh key to multiple remote servers.

Basic command – the command uses sshpass to upload the ssh key to a remote server, this allows you to execute the command and not have to enter in a password to authenticate.

sshpass -p password ssh-copy-id -o StrictHostKeyChecking=no admin@remotehost

Script

#!/bin/bash

remotehosts="$1"
username="admin"
password="MyCoolPassword123"

for host in `cat ${remotehosts}`
do
sshpass -p${password} ssh-copy-id -o StrictHostKeyChecking=no ${username}@${host}
echo "Uploaded key to " ${host}
done

echo "Finished!"

 

Using the script

  1. Download here.
  2. Make it executable
    chmod +x sshcopy.sh
    
  3. Edit the script and change the username and password.
  4. Create a file that contains each host’s IP address or hostname.
  5. Run script (change hostlist.txt to your host list you created in step 3.)
    ./sshcopy.sh hostlist.txt
  6. Wait for the script to finish.

Example:

wget www.incredigeek.com/home/downloads/SSHCopy/sshcopy.sh
chmod +x sshcopy.sh
sed -i s/admin/bob/g sshcopy.sh                      <-- Change username - you can just manually edit the file,
sed -i s/MyCoolPassword123/password/g sshcopy.sh     <-- Change password - it might be easier than using sed
echo "192.168.1.100" >> host.txt                     <-- Add 192.168.1.100 to the host list
echo "Bob" >> host.txt                               <-- Add hostname bob to host list
./sshcopy.sh host.txt                                <-- Upload ssh key to all host's in the host file i.e. "bob" and "192.168.1.100"