HTTP(s) monitoring dashboard webpage via shell script. Parallel checking, thus very fast, only dependencies are curl, coreutils and bash (version 4 or above). For all of you who want a simple script with a nice webpage to check a few websites. Perfect for a wall mounted monitoring display and a Raspberry Pi.
Installation and configuration is easy to do inside the script. It scales well, both on the checking side as the information display page (dense on purpose). Failed checks appear right on top for you to act on.
You can set an expected status code and a max timeout per check, so if you consider your site up when it returns a 302 (redirect) or 401 (unauthorized) the script consider that okay. If the status code is not what is configured or there is a timeout or another error, the script considers the check failed.
If a check fails, the script will check that specific one again after 5 seconds to prevent flapping.
Author: Remy van Elst
What this does not have:
Installation & Configuration
Make sure you have curl installed (
apt install curl). If you need a very simple webserver, try [micro-httpd, by ACME]. (
apt install micro-httpd).
Clone the git repository:
git clone https://github.com/RaymiiOrg/bash-http-monitoring.git cd bash-http-monitoring
srvmon script and add your sites. A few examples are provided. This is the syntax:
urls[gists]="https://gist.github.com" urls[lobsters]="https://lobste.rs" urls[raymii.org]="https://raymii.org" urls[example]="http://example.org:3000/this/is/a/test"
The first part between the square brackets is the name, the second part between the quotes is the URL you want
to monitor. It can be just a domain, an IP or an actual URL, including port and such.
If you want to override the default status code for a check, this is the syntax:
The first part between the square brackets must match the
Further global configuration options include:
maxConcurrentCurls=12 # How many curl checks to run at the same time defaultTimeOut=10 # Max timeout of a check in seconds flapRetry=5 # After how many seconds should we re-check any failed checks? (To prevent flapping) title="Status Dashboard" # Title of the webpage cgi=false # Enable or disable CGI header
Execute the script and send the output to a file in your webservers documentroot:
bash srvmon > /var/www/index.html
View that file in a web browser.
If you want to set up a cronjob, send the output to a temp file and when finished, move that temp
file over the "actual" file. Otherwise you might end up with an incomplete page when the checks are
running. Like so:
* * * * * /bin/bash /opt/srvmon/srvmon > /var/www/index.html.tmp && /bin/mv /var/www/index.html.tmp /var/www/index.html
If the check fails for whatever reason, the "old" page will not be overridden.
Some HTTP servers, like Apache, support CGI scripts. To make it brief, these are scripts which
are handed a HTTP request to reply to.
The main advantage of using the script as a CGI script, is that the page is generated on demand
and as such, provides a live-view on each page load.
If the page is public, this method should be avoided, as it can be easily abused.
If you want to set up CGI mode, you need to copy the script to your server CGI directory.
You can use
docker to try this out. Like so:
docker run -d -p 9090:80 -v $PWD/srvmon:/usr/local/apache2/cgi-bin/srvmon hypoport/httpd-cgi
All checks are okay:
A check has failed:
Here is how it looks with many hosts (also note how fast it executes, 6 seconds):
This is what the early version looked like: