#Releases
Currently the pace of development is very high. Any downloads of the "master" branch will be subject of rapid change.
If you want a stable release, please download from the "stable" branch. The latest release can be found here:
#Description
Nagios Cloudwatch is a set of scripts to help with the Nagios (and derivates) monitoring of Amazon Cloud resources.
Possible checks:
-
Amazon EC2 statuses
- Instance running
-
Amazon Cloudwatch statistics
- Reading/reporting on EC2 instance statistics metrics, such as CPUUtilization, etc
- Reading/reporging on ELB statistics, such as HealthyHostCount, Latency, etc
#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
#Installation:
mkdir /path/to/your/plugins
cd /path/to/your/plugins
git clone git@github.com:maglub/nagios-cloudwatch.git
- Create a new policy for read only access: https://console.aws.amazon.com/iam/home?region=us-west-2#policies ** Create your own policy, policy name (example) "KMG-Group-AWS-Monitoring", Description (example) "Read only policy needed for read only access for external AWS monitoring"
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": "ec2:Describe*",
"Resource": "*"
},
{
"Effect": "Allow",
"Action": "elasticloadbalancing:Describe*",
"Resource": "*"
},
{
"Effect": "Allow",
"Action": [
"cloudwatch:ListMetrics",
"cloudwatch:GetMetricStatistics",
"cloudwatch:Describe*"
],
"Resource": "*"
},
{
"Effect": "Allow",
"Action": "autoscaling:Describe*",
"Resource": "*"
}
]
}
- Create a new user (which will get read only access): https://console.aws.amazon.com/iam/home?region=us-west-2#users ** Make sure you save the credentials/tokens ** Attach the policy above
- 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
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 apt-get install libxslt-dev libxml2-dev
sudo apt-get install build-essential
#sudo gem install aws-sdk-core --pre
sudo gem install aws-sdk -v 1.15
Note: to make ruby1.9.1 default on your system, follow the instructions on:
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
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
Pre-requisites already in place.
#Usage
- Check an ELB (Elastic Load Balancer) for the number of healthy hosts.
./check_cloudwatch.rb --instance="<INSTANCE_NAME>" --namespace="AWS/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"
- --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
You can list available metrics for your instance, your load balancer, etc, by using the --list-metrics parameter.
./check_cloudwatch.rb --namespace="AWS/EC2" -i <instance_id> --list-metrics
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 the AWS Cloudwatch.
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 --namespace="AWS/EC2" -i <instance_id> --metric="CPUUtilization" --window=600 --period=60