Home / server / Questions / 868979
Accepted
Linker3000
Asked: 2017-08-17 07:05:27 +0800 CST

JSON parsing with Nagios plugin

  • 772

I am looking to use Drew Kerrigan's JSON Nagios plugin on GitHub (drewkerrigan/nagios-http-json) to monitor the output from a REST API, but I am struggling to get the query syntax right.

Here is a sample of the JSON that's returned when I hit the Web API:

{"Checks":[
{"description":"can read interconnect 0910", 
"result":"passed"},
{"description":"can read interconnect 1011", 
"result":"passed"},
{"description":"can read linknode 1112", 
"result":"passed"},
{"description":"can read linknode 1213", 
"result":"passed"},
{"description":"can read dbnode 1314", 
"result":"passed"},
{"description":"can read dbnode 1415", 
"result":"passed"},
{"description":"can read dbnode 1516", 
"result":"passed"},
{"description":"can read dbnode 1617", 
"result":"passed"},
{"description":"can read dbnode 1718", 
"result":"passed"},
{"description":"can read main table", 
"result":"passed"},
{"description":"can read secondary table", 
"result":"passed"},
{"description":"can read postcode table", 
"result":"passed"},
{"description":"can read/write to docs folder", 
"result":"passed"},
{"description":"can read/write to config folder", 
"result":"passed"},
{"description":"la integration enabled", 
"result":"passed"},
{"description":"webservice password", 
"result":"passed"},
{"description":"can authenticate in largedb", 
"result":"passed"},
{"description":"can import locales", 
"result":"passed"}
]}

Drew's plugin has an equality test switch:

-q [KEY_VALUE_LIST [KEY_VALUE_LIST ...]], --key_equals [KEY_VALUE_LIST [KEY_VALUE_LIST ...]]
                        Checks equality of these keys and values
                        (key[>alias],value key2,value2) to determine status.
                        Multiple key values can be delimited with colon
                        (key,value1:value2). Return warning if equality check
                        fails

and Drew gives examples of how to structure a query for various key/value syntaxes, but I cannot seem to get it right and I am getting python errors which I expect are down to my query syntax not reflecting the JSON structure.

Can anyone help me with an example for checking whether, say, "can read main table" is "passed".

nagios

1 Answers

  1. Best Answer

    Drew's plugin is not coded to handle that specific JSON format, so I hacked in a small fix to take our JSON data and convert it to a more plugin-friendly structure (simple key:value pairs) - I couldn't change the format of the JSON our app generates as it is used elsewhere and too much would break. In the main program block:

    [SNIP]
else:
    debugPrint(args.debug, 'DEBUG: In expected loop')
    jsondata = response.read()
    data = json.loads(jsondata)
    # Modify the data structure to a format more friendly to the plugin
    newD={}
    for item in data["Checks"]:
            newD[item.get("description")]=item.get("result")
    data = newD
    # End of modification
    debugPrint(args.debug, 'json:')
    debugPrint(args.debug, data, True)
    # Apply rules to returned JSON data
    processor = JsonRuleProcessor(data, args)
[SNIP]
    • 1