Monitor RSS Feed

Hello,

thank you very much for your KB-Post. I'm afraid this may only be possible with Custom Exe/Script Sensors in the moment.

best regards.

Hi, This seems like a good suggestion. I tried to setup a http advanced sensor to monitor http://status.aws.amazon.com/rss/ec2-eu-west-1.rss and alert on changes but the rss feed updates the following causing it to be different every minute:

<pubDate>Wed, 26 Nov 2014 13:18:07 PST</pubDate> <updated>Wed, 26 Nov 2014 13:18:07 PST</updated>

It seems like the http advanced sensor is very close to being able to monitor for RSS feed changes. Is there any way to have it ignore those 2 lines?

This can't be done with the HTTP Sensors (to ignore the first lines of the feed). You can do it with a custom script sensor. We have an Powershell 1 example here, that you would need to adjust to ignore the first lines of the feed:

# ___ ___ _____ ___ 
#| _ \ _ \_  _/ __|
#|  _/  / | || (_ |
#|_| |_|_\ |_| \___|
#    NETWORK MONITOR
#-------------------
# Description: This script will monitor a RSS feed for updates
# Parameters: 
# - AutoUpdate: Call the script with a sensor with autoupdate = false, let a change notification run the same script after x seconds
#  with autoupdate true to reset the sensor to okay state
# - SensorId - Set it manually _after_ the sensor creation, use %sensorid for this in the notification. This way, you can check multiple feeds :) 
# ------------------
# (c) 2014 Stephan Linke | Paessler AG

param(
[int]$autoupdate = 'false'
[string]$SensorId = '00001'
)

# RSS Reader for PRTG
$RssFeedUrl = "https://www.paessler.com"
$RssStored  = "C:\temp\rss-stored-$SensorId.tmp"
$RssLatest     = "C:\temp\rss-latest-$SensorId.tmp"

# Download the feed 
$wc = New-Object Net.WebClient 
$feedContent = $wc.DownloadString($RssFeedUrl)

# Store the feed
$feedContent | Out-File $rssLatest

if(!(Test-Path($rssStored))){
    if($autoupdate -eq 'true'){
        $feedContent | Out-File $RssStored
    }
}
    
# Get the content into xml object 
[xml]$StoredContent = get-content $RssStored
[xml]$LatestContent = get-content $RssLatest

if($StoredContent.rss.channel.item[0].title -eq $LatestContent.rss.channel.item[0].title){
    0:$StoredContent.rss.channel.item[0].title
    exit 0
}
else {
    1:"Feed updated: "$LatestContent.rss.channel.item[0].title
    exit 1
}

Please be aware that the script comes without further warranty and support.

Hello,

did somebody else test or try it? I did change the param sector and added the colon at the first line so no Parameter Error appears anymore and changed the content false to integer:

param(
[int]$autoupdate = '0',
[string]$SensorId = '00001'
)

Now the C:/temp path does not get found, although it exists and rights are open? Any ideas somebody?

Regards peet

Sorry I have to revamp the script in order for it to work properly. Sorry for the sloppy code! The rewrite might take a bit, depending on my schedule.

Hello Stephan,

no problem, I would do it myself, but I am more of a pseudo-coder than syntxguru, so i'll be waiting.

Did not find other code out there, so I guess a few more people would appreciate this scriptcode of yours - RSS feeds get more and more important to monitor on changes and to have a reliable probe mechanism with escalation and mailing functionalities.

Thanks a million for your efforts.

Regards peet

Just so you know, I didn't forget you. The script is mostly done, I have to work on the updating mechanism, though :)