Nagios Plugin: Wildcard for nagios-http-json keys - json

Looking to use the nagios plugin nagios-http-json https://github.com/drewkerrigan/nagios-http-json to check a json response.
There is an example (I slightly modified):
Data for keys ring_members(0).numberToCheck, ring_members(1).numberToCheck, ring_members(2).numberToCheck:
{
"ring_members": [
{"numberToCheck": "10"},
{"numberToCheck": "20"},
{"numberToCheck": "30"}
]
}
If I want to check the first element in the response's array I could write:
plugins/check_http_json.py .... -w ring_members(0).numberToCheck,#20:
To check if ring_members position 0 key numberToChecks value is greater than or equal to 20 and flag a warning if true.
I could repeat -w ring_members(0).numberToCheck,#20: ring_members(1).numberToCheck,#20: ... to check all the values.
However is it possible to check each position of ring_members, when the length of ring_members is unknown?

I ended up modifying the plugin check_http_json.py, and adding a custom check for a "%all" instead of index position:
def gte(self, key, value):
if '(%all)' in key:
array_key = key.split('(%all)')[0]
array_full = self.get(array_key)
for item in array_full:
if float(item['numberToCheck']) >= float(value):
return True
return False
return self.exists(key) and float(self.get(key)) >= float(value)
Then pass the following, plugins/check_http_json.py ... -w ring_members(%all),#20:
#20: is gte -> Greater than or equal to.
This results with checking ring_members(0 - ring_members.length-1).numberToCheck >= 20

Related

Play JSON Parse and Extract Elements Without a Key Path

I have a JSON that looks like this, yes the JSON is a valid format.
[2,
"19223201",
"BootNotification",
{
"reason": "PowerUp",
"chargingStation": {
"model": "SingleSocketCharger",
"vendorName": "VendorX"
}
}
]
I'm using Play framework's JSON library and I would like to understand how I could parse the 3rd line and extract the BootNotification value as a String.
If it had a key, I can use that key to traverse the JSON and get the corresponding value, but this is not the case here. I also do not have the possibility to load this line by line and infer from line number 3 as with the example above.
Any suggestions on how I could do this?
I think, I have found out a way after trying all this on Ammonite. Here is what I could do:
# val input: JsValue = Json.parse("""[2,"12345678","BNR",{"reason":"PowerUp"}]""")
input: JsValue = JsArray(ArrayBuffer(JsNumber(2), JsString("12345678"), JsString("BNR"), JsObject(Map("reason" -> JsString("PowerUp")))))
Parsing the JSON, I get a nice array and I know that I always expect just 4 elements in the Array, so explicitly looking for an element with the array index is what I need. So to get the text at position 3, I could do the following:
# (input \ 2)
res2: JsLookupResult = JsDefined(JsString("BNR"))
# (input \ 2).toOption
res3: Option[JsValue] = Some(JsString("BNR"))
# (input \ 2).toOption.isDefined
res4: Boolean = true

How to parse a string to key value pair using regex?

What is the best way to parse the string into key value pair using regex?
Sample input:
application="fre" category="MessagingEvent" messagingEventType="MessageReceived"
Expected output:
application "fre"
Category "MessagingEvent"
messagingEventType "MessageReceived"
We already tried the following regex and its working.
application=(?<application>(...)*) *category=(?<Category>\S*) *messagingEventType=(?<messagingEventType>\S*)
But we want a generic regex which will parse the sample input to the expected output as key value pair?
Any idea or solution will be helpful.
input = 'application="fre" category="MessagingEvent" messagingEventType="MessageReceived"'
puts input.
scan(/(\w+)="([^"]+)"/). # scan for KV-pairs
map{ |k, v| %Q|#{k.ljust(30,' ')}"#{v}"| }. # adjust as you requested
join($/) # join with platform-dependent line delimiters
#⇒ application "fre"
# category "MessagingEvent"
# messagingEventType "MessageReceived"
Instead of using regex, it can be done by spliting and storing the string in hash like below:
input = 'application="fre" category="MessagingEvent" messagingEventType="MessageReceived"'
res = {}
input.split.each { |str| a,b = str.split('='); res[a] = b}
puts res
==> {"application"=>"\"fre\"", "category"=>"\"MessagingEvent\"", "messagingEventType"=>"\"MessageReceived\""}

Parse any number of subkeys in a perl hash

I have a perl hash that is obtained from parsing JSON. The JSON could be anything a user defined API could generated. The goal is to obtain a date/time string and determine if that date/time is out of bounds according to a user defined threshold. The only issue I have is that perl seems a bit cumbersome when dealing with hash key/subkey iteration. How can I look through all the keys and determine if a key or subkey exists throughout the hash? I have read many threads throughout stackoverflow, but nothing that exactly meets my needs. I only started perl last week so I may be missing something... Let me know if that's the case.
Below is the "relevant" code/subs. For all code see: https://gitlab.com/Jedimaster0/check_http_freshness
use warnings;
use strict;
use LWP::UserAgent;
use Getopt::Std;
use JSON::Parse 'parse_json';
use JSON::Parse 'assert_valid_json';
use DateTime;
use DateTime::Format::Strptime;
# Verify the content-type of the response is JSON
eval {
assert_valid_json ($response->content);
};
if ( $# ){
print "[ERROR] Response isn't valid JSON. Please verify source data. \n$#";
exit EXIT_UNKNOWN;
} else {
# Convert the JSON data into a perl hashrefs
$jsonDecoded = parse_json($response->content);
if ($verbose){print "[SUCCESS] JSON FOUND -> ", $response->content , "\n";}
if (defined $jsonDecoded->{$opts{K}}){
if ($verbose){print "[SUCCESS] JSON KEY FOUND -> ", $opts{K}, ": ", $jsonDecoded->{$opts{K}}, "\n";}
NAGIOS_STATUS(DATETIME_DIFFERENCE(DATETIME_LOOKUP($opts{F}, $jsonDecoded->{$opts{K}})));
} else {
print "[ERROR] Retreived JSON does not contain any data for the specified key: $opts{K}\n";
exit EXIT_UNKNOWN;
}
}
sub DATETIME_LOOKUP {
my $dateFormat = $_[0];
my $dateFromJSON = $_[1];
my $strp = DateTime::Format::Strptime->new(
pattern => $dateFormat,
time_zone => $opts{z},
on_error => sub { print "[ERROR] INVALID TIME FORMAT: $dateFormat OR TIME ZONE: $opts{z} \n$_[1] \n" ; HELP_MESSAGE(); exit EXIT_UNKNOWN; },
);
my $dt = $strp->parse_datetime($dateFromJSON);
if (defined $dt){
if ($verbose){print "[SUCCESS] Time formatted using -> $dateFormat\n", "[SUCCESS] JSON date converted -> $dt $opts{z}\n";}
return $dt;
} else {
print "[ERROR] DATE VARIABLE IS NOT DEFINED. Pattern or timezone incorrect."; exit EXIT_UNKNOWN
}
}
# Subtract JSON date/time from now and return delta
sub DATETIME_DIFFERENCE {
my $dateInitial = $_[0];
my $deltaDate;
# Convert to UTC for standardization of computations and it's just easier to read when everything matches.
$dateInitial->set_time_zone('UTC');
$deltaDate = $dateNowUTC->delta_ms($dateInitial);
if ($verbose){print "[SUCCESS] (NOW) $dateNowUTC UTC - (JSON DATE) $dateInitial ", $dateInitial->time_zone->short_name_for_datetime($dateInitial), " = ", $deltaDate->in_units($opts{u}), " $opts{u} \n";}
return $deltaDate->in_units($opts{u});
}
Sample Data
{
"localDate":"Wednesday 23rd November 2016 11:03:37 PM",
"utcDate":"Wednesday 23rd November 2016 11:03:37 PM",
"format":"l jS F Y h:i:s A",
"returnType":"json",
"timestamp":1479942217,
"timezone":"UTC",
"daylightSavingTime":false,
"url":"http:\/\/www.convert-unix-time.com?t=1479942217",
"subkey":{
"altTimestamp":1479942217,
"altSubkey":{
"thirdTimestamp":1479942217
}
}
}
[SOLVED]
I have used the answer that #HåkonHægland provided. Here are the below code changes. Using the flatten module, I can use any input string that matches the JSON keys. I still have some work to do, but you can see the issue is resolved. Thanks #HåkonHægland.
use warnings;
use strict;
use Data::Dumper;
use LWP::UserAgent;
use Getopt::Std;
use JSON::Parse 'parse_json';
use JSON::Parse 'assert_valid_json';
use Hash::Flatten qw(:all);
use DateTime;
use DateTime::Format::Strptime;
# Verify the content-type of the response is JSON
eval {
assert_valid_json ($response->content);
};
if ( $# ){
print "[ERROR] Response isn't valid JSON. Please verify source data. \n$#";
exit EXIT_UNKNOWN;
} else {
# Convert the JSON data into a perl hashrefs
my $jsonDecoded = parse_json($response->content);
my $flatHash = flatten($jsonDecoded);
if ($verbose){print "[SUCCESS] JSON FOUND -> ", Dumper($flatHash), "\n";}
if (defined $flatHash->{$opts{K}}){
if ($verbose){print "[SUCCESS] JSON KEY FOUND -> ", $opts{K}, ": ", $flatHash>{$opts{K}}, "\n";}
NAGIOS_STATUS(DATETIME_DIFFERENCE(DATETIME_LOOKUP($opts{F}, $flatHash->{$opts{K}})));
} else {
print "[ERROR] Retreived JSON does not contain any data for the specified key: $opts{K}\n";
exit EXIT_UNKNOWN;
}
}
Example:
./check_http_freshness.pl -U http://bastion.mimir-tech.org/json.html -K result.creation_date -v
[SUCCESS] JSON FOUND -> $VAR1 = {
'timestamp' => '20161122T200649',
'result.data_version' => 'data_20161122T200649_data_news_topics',
'result.source_version' => 'kg_release_20160509_r33',
'result.seed_version' => 'seed_20161016',
'success' => 1,
'result.creation_date' => '20161122T200649',
'result.data_id' => 'data_news_topics',
'result.data_tgz_name' => 'data_news_topics_20161122T200649.tgz',
'result.source_data_version' => 'seed_vtv: data_20161016T102932_seed_vtv',
'result.data_digest' => '6b5bf1c2202d6f3983d62c275f689d51'
};
Odd number of elements in anonymous hash at ./check_http_freshness.pl line 78, <DATA> line 1.
[SUCCESS] JSON KEY FOUND -> result.creation_date:
[SUCCESS] Time formatted using -> %Y%m%dT%H%M%S
[SUCCESS] JSON date converted -> 2016-11-22T20:06:49 UTC
[SUCCESS] (NOW) 2016-11-26T19:02:15 UTC - (JSON DATE) 2016-11-22T20:06:49 UTC = 94 hours
[CRITICAL] Delta hours (94) is >= (24) hours. Data is stale.
You could try use Hash::Flatten. For example:
use Hash::Flatten qw(flatten);
my $json_decoded = parse_json($json_str);
my $flat = flatten( $json_decoded );
say "found" if grep /(?:^|\.)\Q$key\E(?:\.?|$)/, keys %$flat;
You can use Data::Visitor::Callback to traverse the data structure. It lets you define callbacks for different kinds of data types inside your structure. Since we're only looking at a hash it's relatively simple.
The following program has a predefined list of keys to find (those would be user input in your case). I converted your example JSON to a Perl hashref and included it in the code because the conversion is not relevant. The program visits every hashref in this data structure (including the top level) and runs the callback.
Callbacks in Perl are code references. These can be created in two ways. We're doing the anonymous subroutine (sometimes called lambda function in other languages). The callback gets passed two arguments: the visitor object and the current data substructure.
We'll iterate all the keys we want to find and simply check if they exist in that current data structure. If we see one, we count it's existence in the %seen hash. Using a hash to store things we have seen is a common idiom in Perl.
We're using a postfix if here, which is convenient and easy to read. %seen is a hash, so we access the value behind the $key with $seen{$key}, while $data is a hash reference, so we use the dereferencing operator -> to access the value behind $key with $data->{$key}.
The callback needs us to return the $data again so it continues. The last line is just there, it's not important.
I've used Data::Printer to output the %seen hash because it's convenient. You can also use Data::Dumper if you want. In production, you will not need that.
use strict;
use warnings;
use Data::Printer;
use Data::Visitor::Callback;
my $from_json = {
"localDate" => "Wednesday 23rd November 2016 11:03:37 PM",
"utcDate" => "Wednesday 23rd November 2016 11:03:37 PM",
"format" => "l jS F Y h:i:s A",
"returnType" => "json",
"timestamp" => 1479942217,
"timezone" => "UTC",
"daylightSavingTime" =>
0, # this was false, I used 0 because that's a non-true value
"url" => "http:\/\/www.convert-unix-time.com?t=1479942217",
"subkey" => {
"altTimestamp" => 1479942217,
"altSubkey" => {
"thirdTimestamp" => 1479942217
}
}
};
my #keys_to_find = qw(timestamp altTimestamp thirdTimestamp missingTimestamp);
my %seen;
my $visitor = Data::Visitor::Callback->new(
hash => sub {
my ( $visitor, $data ) = #_;
foreach my $key (#keys_to_find) {
$seen{$key}++ if exists $data->{$key};
}
return $data;
},
);
$visitor->visit($from_json);
p %seen;
The program outputs the following. Note this is not a Perl data structure. Data::Printer is not a serializer, it's a tool to make data human readable in a convenient way.
{
altTimestamp 1,
thirdTimestamp 1,
timestamp 1
}
Since you also wanted to constraint the input, here's an example how to do that. The following program is a modification of the one above. It allows to give a set of different constraints for every required key.
I've done that by using a dispatch table. Essentially, that's a hash that contains code references. Kind of like the callbacks we use for the Visitor.
The constraints I've included are doing some things with dates. An easy way to work with dates in Perl is the core module Time::Piece. There are lots of questions around here about various date things where Time::Piece is the answer.
I've only done one constraint per key, but you could easily include several checks in those code refs, or make a list of code refs and put them in an array ref (keys => [ sub(), sub(), sub() ]) and then iterate that later.
In the visitor callback we are now also keeping track of the keys that have %passed the constraints check. We're calling the coderef with $coderef->($arg). If a constraint check returns a true value, it gets noted in the hash.
use strict;
use warnings;
use Data::Printer;
use Data::Visitor::Callback;
use Time::Piece;
use Time::Seconds; # for ONE_DAY
my $from_json = { ... }; # same as above
# prepare one of the constraints
# where I'm from, Christmas eve is considered Christmas
my $christmas = Time::Piece->strptime('24 Dec 2016', '%d %b %Y');
# set up the constraints per required key
my %constraints = (
timestamp => sub {
my ($epoch) = #_;
# not older than one day
return $epoch < time && $epoch > time - ONE_DAY;
},
altTimestamp => sub {
my ($epoch) = #_;
# epoch value should be an even number
return ! $epoch % 2;
},
thirdTimestamp => sub {
my ($epoch) = #_;
# before Christmas 2016
return $epoch < $christmas;
},
);
my %seen;
my %passed;
my $visitor = Data::Visitor::Callback->new(
hash => sub {
my ( $visitor, $data ) = #_;
foreach my $key (%constraints) {
if ( exists $data->{$key} ) {
$seen{$key}++;
$passed{$key}++ if $constraints{$key}->( $data->{$key} );
}
}
return $data;
},
);
$visitor->visit($from_json);
p %passed;
The output this time is:
{
thirdTimestamp 1,
timestamp 1
}
If you want to learn more about the dispatch tables, take a look at chapter two of the book Higher Order Perl by Mark Jason Dominus which is legally available for free here.

How can we provide multiple values for a Single argument either in services.conf or comands.conf

Here I am trying to use a plugin to check whether the service running or not, if there is any warning or any critical action required, at the same time the performance parameter.
We have used below plugin to check if a server is alive or not and read it's performance data JSON
https://github.com/drewkerrigan/nagios-http-json
I am trying to read a JSON file as below which is hosted on http://localhost:8080/sample.json
The plugin works perfectly on Command line, it shows me all the Metrics available.
$:/usr/lib/nagios/plugins$ ./check_http_json.py -H localhost:8080 -p sample.json -m metrics.etp_count metrics.atc_count
OK: Status OK.|'metrics.etp_count'=101 'metrics.atc_count'=0
But when I try the same in Icinga2 configuration, it doesn't show me this performance metrics, although it doesn't give any error but at the same time it don't show any value.
find the JSON, Command.conf and Service.conf as follows.
{
"metrics": {
"etp_count": "0",
"atc_count": "101",
"mean_time": -1.0,
}
}
Below are my commands.conf and services.conf
commands.conf
/* Json Read Command */
object CheckCommand "json_check"{
import "plugin-check-command"
command = [PluginDir + "/check_http_json.py"]
arguments = {
"-H" = "$server_port$"
"-p" = "$json_path$"
"-w" = "$warning_value$"
"-c" = "$critical_value$"
"-m" = "$Metrics1$,$Metrics2$"
}
}
services.conf
apply Service "json"{
import "generic-service"
check_command = "json_check"
vars.server_port="localhost:8080"
vars.json_path="sample.json"
vars.warning_value="metrics.etp_count,1:100"
vars.critical_value="metrics.etp_count,101:1000"
vars.Metrics1="metrics.etp_count"
vars.Metrics2="metrics.atc_count"
assign where host.name == NodeName
}
Does any one have any idea how can we pass multiple values in Command.conf and Service.conf??
I have resolved the issue.
I had to change the Plugin file "check_http_json.py" for below code
def checkMetrics(self):
"""Return a Nagios specific performance metrics string given keys and parameter definitions"""
metrics = ''
warning = ''
critical = ''
if self.rules.metric_list != None:
for metric in self.rules.metric_list:
Replaced With
def checkMetrics(self):
"""Return a Nagios specific performance metrics string given keys and parameter definitions"""
metrics = ''
warning = ''
critical = ''
if self.rules.metric_list != None:
for metric in self.rules.metric_list[0].split():
Actually the issue was the list was not handled properly, so it was not able to iterate through the items in the list, it was considering it as a single string due to services.config file.
it had to be further get split to get the items in the Metrics string.

A shorter non-repeating alphanumeric code than UUID in MySQL

Is it possible for MySQL database to generate a 5 or 6 digit code comprised of only numbers and letters when I insert a record? If so how?
Just like goo.gl, bit.ly and jsfiddle do it. For exaple:
http://bit.ly/3PKQcJ
http://jsfiddle.net/XzKvP
cZ6ahF, 3t5mM, xGNPN, xswUdS...
So UUID_SHORT() will not work because it returns a value like 23043966240817183
Requirements:
Must be unique (non-repeating)
Can be but not required to be based off of primary key integer value
Must scale (grow by one character when all possible combinations have been used)
Must look random. (item 1234 cannot be BCDE while item 1235 be BCDF)
Must be generated on insert.
Would greatly appreciate code examples.
Try this:
SELECT LEFT(UUID(), 6);
I recommend using Redis for this task, actually. It has all the features that make this task suitable for its use. Foremost, it is very good at searching a big list for a value.
We will create two lists, buffered_ids, and used_ids. A cronjob will run every 5 minutes (or whatever interval you like), which will check the length of buffered_ids and keep it above, say, 5000 in length. When you need to use an id, pop it from buffered_ids and add it to used_ids.
Redis has sets, which are unique items in a collection. Think of it as a hash where the keys are unique and all the values are "true".
Your cronjob, in bash:
log(){ local x=$1 n=2 l=-1;if [ "$2" != "" ];then n=$x;x=$2;fi;while((x));do let l+=1 x/=n;done;echo $l; }
scale=`redis-cli SCARD used_ids`
scale=`log 16 $scale`
scale=$[ scale + 6]
while [ `redis-cli SCARD buffered_ids` -lt 5000 ]; do
uuid=`cat /dev/urandom | tr -cd "[:alnum:]" | head -c ${1:-$scale}`
if [ `redis-cli SISMEMBER used_ids $uuid` == 1]; then
continue
fi
redis-cli SADD buffered_ids $uuid
done
To grab the next uid for use in your application (in pseudocode because you did not specify a language)
$uid = redis('SPOP buffered_ids');
redis('SADD used_ids ' . $uid);
edit actually there's a race condition there. To safely pop a value, add it to used_ids first, then remove it from buffered_ids.
$uid = redis('SRANDMEMBER buffered_ids');
redis('SADD used_ids ' . $uid);
redis('SREM buffered_ids ' . $uid);