What is Simverest?

Simverest acts as a simple dashboard for a Varnish cache server. It will provide you with information such as the current state of the backends, what the current processing load on the server is, and other useful stats provided by various Varnish programs.

Simverest uses common command line tools (e.g. grep, awk, top) to parse the output of these tools and provides a central location where that information can be exposed to users without having to know these commands.

Getting Started

In its most basic form, you'll connect to a Varnish server through SSH with a username and password

simverest.exe <ip address of server> <username> <password>

or

python daemon.py <ip address of server> <username> <password>

This will start collecting information from the Varnish server and also start a web server on port 8080 (can be changed via command line switch). Users can then navigate to http://<ip address of simverest>:8080 and they will get a dashboard showing various stats about the Varnish server.

To get a full list of options, you can use the following command

simverest.exe -h

or

python daemon.py -h

Alternatively, you can specify a .ini file with multiple servers

python daemon.py -c simverest.ini

Here is an example ini file. (Note: At the moment, the headers are not used for anything but that may change)

[varnish1]
host=192.168.0.65
username=simverest_user
password=bR8bUtr9

[varnish2]
host=192.168.0.66
username=simverest_user2
password=Q7dRuspa

API

Part of the usefulness of Simverest is that it provides a web api that returns current information about the state of a Varnish server.

An example would be the following:

http://localhost:8080/api/servers

returns

{"servers": ["VARNISH1"]}

You can then drill down further to get a full picture of the server:

http://localhost:8080/api/server/VARNISH1

returns

{
   "process": {
      "virtualmem":"466m",
      "reservedmem":"111m",
      "cpu":"0.0",
      "memory":"2.8"
   },
   "timestamp":"2012-03-07T22:49:08Z",
   "varnishstats":[
      {
         "name":"client_conn",
         "value":10.428571428571429,
         "description":"Client connections accepted"
      },
      {
         "name":"client_req",
         "value":14.0,
         "description":"Client requests received"
      },
      <snip>...
   ],
   "backends":[
      {
         "timestamp":"2012-03-07T22:48:21Z",
         "state":"healthy",
         "name":"WEB1"
         "status_code": "200",
         "status_text":"OK"
      },
      {
         "timestamp":"2012-03-07T22:48:25Z",
         "state":"sick",
         "name":"WEB2",
         "status_code": "500",
         "status_text":"Internal Server Error"
      }
   ]
}

Depending on the information required, you can drill down even further

http://localhost:8080/api/server/VARNISH1/backend/WEB1/state

returns

healthy

Contributing

Please submit any bugs to the Github issue tracker: https://github.com/rjnienaber/simverest/issues

If you want to contribute send me a pull request :)

License

Copyright 2012 Richard Nienaber

Simverest is released under the GPL license:

If you submit a pull request, please note that you agree that your code will fall under this license.