I had an ubuntu server with 8.04LTS upgraded to 10.04LTS (not quite making it to 12.04, but that’s in the works) with webmin, LAMP, postfix, etc. I used webmin to install dovecot after I already configured postfix to receive mail without requiring SSL with plaintext. It’s an internal only server used to testing purposes, so I don’t mind if someone is sniffing the test passwords that only apply to this box.

Anyway, I was receiving the following in my /var/log/mail.err

Oct 17 08:35:33 SERVERNAME dovecot: POP3(USERNAME): mail_location not set and autodetection failed: Mail storage autodetection failed with home=/home/USERNAME
Oct 17 08:35:33 SERVERNAME dovecot: POP3(USERNAME): Fatal: Namespace initialization failed

Great. Brief search tells me that dovecot’s automatic detection failed (duh) and the fix is to enable the mail location in the configuration file
nano /etc/dovecot/dovecot.conf
Find #mail_location
Assuming it’s commented out, I just added the following below the line:
mail_location = maildir:~/Maildir
Save and close
/etc/init.d/dovecot restart

Recently had to start monitoring a confluence installation on a virtual server using Nagios. Nagios’s built-in check_http looked like it could solve my woes. Unfortunately this was a slight pain due to the fact that confluence uses a non-standard port. So I had to relearn the commands.

I edited the service check first
nano /usr/local/nagios/etc/objects/commands.cfg
I copied the check_http command into a new one:

define command {
command_name check_http_port
command_line $USER1$/check_http -I $ARG1$ -u $ARG2$ -p $ARG3$ -s $ARG4$
}

So the command would be ./check_http -I (IP/Hostname) -u (URL Full Address) -p (Port) -s (String to look for). Technically this will already warn if there is a 400 or 500 error, but I also wanted to verify that the string could be found.

Now we edit the configuration of the system itself
nano /usr/local/nagios/etc/objects/confluence.cfg

define host{
use linux-server
host_name confluence
alias confluence
address 10.555.555.555
parents parent1, switch1, mfer1
hostgroups linux-production-servers, datacenter2
}

define service{
use generic-service
host_name confluence
service_description HTTP
check_command check_http_port!confluence!http://confluence:8090/login.action?os_destination=%2Fhomepage.action!8090!”Remember me”
}

Using the above check_command, you’re able to connect to the server and port listed above and check for the familiar login “remember me” string.

I had setup vsftp for SSL (FTPES), but needed a way to send an alert to customer support whenever a file had been uploaded. Otherwise the support staff would need to manually check each customer’s folders to see if anything new had arrived.

Install Dnotify
apt-get install dnotify

Create your startup script
nano /dnotify.sh

dnotify -b -p 1 -r -C /home/ -e /email.sh {}

This will run dnotify in the -b background, no more than one -p process, -r recursive folder (subfolders), -C for file creations only, -e execute the following script.

Create your email script
nano /email.sh

#!/bin/bash
DIR=”$1″
rm /upload.txt
echo “Dear User,”>>/upload.txt
echo “A new file has been uploaded to the $DIR directory”>>/upload.txt
cat /upload.txt | mailx -s “New FTP File Upload” customersupport@domain.tld

Make both scripts run-able
chmod +x email.sh
chmod +x dnotify.sh

Run the script and test
./dnotify.sh
Upload a file using FTP/WinSCP/WGET or another method to any of the folders you’re searching (my script searches all of /home and subfolders).

I added this as a startup script.

I got most of my help from nixcraft