Description

Nagios Cloudwatch is a set of scripts to help with the Nagios (and derivates) monitoring of Amazon Cloud resources. Features includes:

Amazon AWS cost monitoring
Amazon EC2
- Instance running - Shows the running status of an instance
- Statistics metrics - Lets you monitor and alert on all AWS EC2 metrics (like CPUUtilization)
Amazon ELB
- Statistics metrics

Installation:

3 simple steps

Download
Configure
Run

Download

Either download the lastest stable release as a tar-ball or zip-file, or clone the git repository.

mkdir /path/to/your/plugins
cd /path/to/your/plugins
wget -O nagios-cloudwatch.latest.tar.gz https://github.com/maglub/nagios-cloudwatch/tarball/master
tar xvzf nagios-cloudwatch.latest.tar.gz

mkdir /path/to/your/plugins
cd /path/to/your/plugins
git clone git@github.com:maglub/nagios-cloudwatch.git
cd nagios-cloudwatch
git checkout stable

Configure

Create a read-only user in AWS and associate it with your environment
Put the access key and secret key in a config.yml file in the same directory as these scripts (or somewhere else if you intend to use the -C parameter)

aws:
  #======================
  #--- authentication
  #======================
  access_key_id: YOUR_ACCESS_KEY
  secret_access_key: YOUR_SECRET_KEY

  #========================================
  #--- default region, unless overridden on the command line
  #========================================
  #--- possible regions us-west-1 us-west-2 eu-west-1, etc...
  region: us-west-2

  #======================
  #--- Proxy config
  #======================
  #proxy_uri: http://user:passwd@IP:PORT

Run

Here are a couple of examples on how to run the script:


$ ./check_cloudwatch.rb --ec2 --list-instances
Name: vpn-v001ec2          Id: i-91f62199     privateIp: 192.168.99.6       State: Zone: running
Name: kmg-test002ec2       Id: i-7ef62176     privateIp: 192.168.99.10      State: Zone: running
Name: win-test003ec2       Id: i-9956e691     privateIp: 192.168.99.20      State: Zone: stopped


$ ./check_cloudwatch.rb --ec2 --instance=i-7ef62176 --list-metrics
i-7ef62176;CPUUtilization
i-7ef62176;StatusCheckFailed_System
i-7ef62176;DiskWriteBytes
i-7ef62176;NetworkIn
i-7ef62176;DiskReadOps
i-7ef62176;NetworkOut
i-7ef62176;StatusCheckFailed_Instance
i-7ef62176;DiskReadBytes
i-7ef62176;DiskWriteOps
i-7ef62176;StatusCheckFailed


$ ./check_cloudwatch.rb --ec2 --instance=i-7ef62176 --metric=CPUUtilization --window=600 --period=300 -w 80 -c 95
OK - Id: i-7ef62176 Metric: CPUUtilization, Last Value: 0.334000 Unit: Percent (2014-06-16 15:43:00 UTC)
|Average=0.334000 Minimum=0.000000 Maximum=1.670000 Sum=1.670000

Pre requisites

Ruby environment with ruby version > 1.9.1 (see below)

Configuration file config.yml, unless you supply the credentials on the command line

Ruby

Ubuntu 12.04 LTS

If your installation come with ruby 1.8, you might have to start the script with /usr/bin/ruby1.9.1 ./check_cloudwatch.rb, unless you follow the second step on how to make ruby1.9.1 default in your installation.

sudo apt-get install -y ruby1.9.1 ruby1.9.1-dev \
     rubygems1.9.1 irb1.9.1 ri1.9.1 rdoc1.9.1 \
     build-essential libopenssl-ruby1.9.1 libssl-dev zlib1g-dev

sudo gem install aws-sdk-core --pre

Note: to make ruby1.9.1 default on your system, follow the instructions on:

https://leonard.io/blog/2012/05/installing-ruby-1-9-3-on-ubuntu-12-04-precise-pengolin/

sudo apt-get update

sudo apt-get install ruby1.9.1 ruby1.9.1-dev \
   rubygems1.9.1 irb1.9.1 ri1.9.1 rdoc1.9.1 \
   build-essential libopenssl-ruby1.9.1 libssl-dev zlib1g-dev

sudo update-alternatives --install /usr/bin/ruby ruby /usr/bin/ruby1.9.1 400 \
          --slave   /usr/share/man/man1/ruby.1.gz ruby.1.gz \
                         /usr/share/man/man1/ruby1.9.1.1.gz \
         --slave   /usr/bin/ri ri /usr/bin/ri1.9.1 \
         --slave   /usr/bin/irb irb /usr/bin/irb1.9.1 \
         --slave   /usr/bin/rdoc rdoc /usr/bin/rdoc1.9.1

 # choose your interpreter
 # changes symlinks for /usr/bin/ruby , /usr/bin/gem
 # /usr/bin/irb, /usr/bin/ri and man (1) ruby
 sudo update-alternatives --config ruby
 sudo update-alternatives --config gem

 # now try
 ruby --version

RedHat/CentOS

https://gist.github.com/trevorrowe/1870314

sudo yum install -y gcc make \
libxml2 libxml2-devel libxslt libxslt-devel \
rubygems ruby-devel

sudo gem install nokogiri -- --with-xml2-lib=/usr/local/lib \
--with-xml2-include=/usr/local/include/libxml2 \
--with-xslt-lib=/usr/local/lib \
--with-xslt-include=/usr/local/include

sudo gem install aws-sdk --no-ri --no-rdoc

OP5 Appliance (CentOS)

Pre-requisites already in place.

Usage

Examples

Check an ELB (Elastic Load Balancer) for the number of healthy hosts.

./check_cloudwatch.rb --instance="<INSTANCE_NAME>" --elb --metric="HealthyHostCount" --window=120 --period=60 --critical=:1+ --warning=:2+
OK - Metric: HealthyHostCount, Last Average: 2.0 Count (2014-06-14 13:34:00 UTC)
|Average=2.0,Minimum=2.0,Maximum=2.0,Sum=240.0

Check an ELB for the total number of ok requests over the last 5 minutes, warning when the number of requests equal or exceed 10 requests, critical at 15

./check_cloudwatch.rb -i <INSTANCE_NAME> --window=3600 --metric=HTTPCode_Backend_2XX --window=300 --period=300 --critical=15 --warning=10 --statistics="Sum"

Thresholds

--warning={@}{+}, -w {@}{+}
--critical={@}{+}, -c {@}{+}

The threshold parameter can be a single value or a range, and can handle decimal values.

A threshold can be checked to be within a range, or outside a range.
To alert when a value is outside a range, use the prefix "@".

The thresholds can be "soft" or "hard", meaning that ha hard threshold will include the parameter value (by comparing >= or <=). A soft threshold means that the check will not trigger when the checked value is equal to the threshold value (by comparing > or <).

A soft threshold is selected by suffixing "+" to the threshold.

Examples of valid thresholds are:

1, 1.0, 1:+, :1.5, 0:1000, @1:100

"-c 75" will trigger when the value is equal to or larger than 75
"-c 75+" will trigger when the value is larger than 75
"-c 0:1" will trigger when the value is equal to or larger than 0 and equal to or less than 1
"-c 0:1+" will trigger when the value is larger than 0 and less than 1
"-c @0:1+" will trigger when the value is outside the soft range

Listing metrics

You can list available metrics for your instance, your load balancer, etc, by using the --list-metrics parameter.

./check_cloudwatch.rb --ec2 -i INSTANCE_ID  --list-metrics

Statistics window, and statistics period

The collection of AWS metrics is not done every minute. For example CPUUtilization is collected every 5 minutes. If you are asking for a window of 60 seconds and a period of 60 seconds, it is very likely that Cloudwatch will return an empty result set since there is no data to be presented for that period. This is a feature of how the AWS Cloudwatch data is collected.

The workaround for this is to ask for a longer period, say 10 minutes or longer, to make sure you will get at least one metric in your result set.

./check_cloudwatch.rb --ec2 -i INSTANCE_ID --metric="CPUUtilization" --window=600 --period=60

Nagios-cloudwatch

Nagios check for AWS Cloudwatch statistics/metrics