Scripting a StatsD, MongoDB, ElasticSearch metrics server on Azure with Powershell

At Mailcloud I am constantly destroying and rebuilding environments (intentionally!), especially the performance test ones. I also need to gather oodles of metrics from these tests, and I have a simple script to create the VM and another to install all of the tools I need.

This article will cover using a simple Powershell script to create the Linux VM and then a slightly less simple bash script to install all the goodies. It’s not as complicated as it may look, and considering you can get something running in a matter of minutes from a couple of small scripts I think it’s pretty cool!

Stage 1, Creating the VM using Powershell

Set up the variables

# os configuration
# Get-AzureVMImage | Select ImageName
# I wanted an ubuntu 14.10 VM:
$ImageName = "b39f27a8b8c64d52b05eac6a62ebad85__Ubuntu-14_10-amd64-server-20140625-alpha1-en-us-30GB"

# account configuration
$ServiceName = "your-service-here"
$SubscriptionName= "your azure subscription name here"
$StorageAccount = "your storage account name here"
$Location = "your location here"

# vm configuration - setting up ssh keys is better, username/pwd is easier.
$user = "username"
$pwd = "p@ssword"

# ports
## ssh
$SSHPort = 53401 #set something specific for ssh else powershell generates a random one

## statsd
$StatsDInputPort = 1234
$StatsDAdminPort = 5678

## elasticsearch
$ElasticSearchPort = 12345

Get your Azure subscription info

Set-AzureSubscription -SubscriptionName $SubscriptionName `
                    -CurrentStorageAccountName $StorageAccount

Select-AzureSubscription -SubscriptionName $SubscriptionName

Create the VM

Change “Small” to one of the other valid instance sizes if you need to.

New-AzureVMConfig -Name $ServiceName -InstanceSize Small -ImageName $ImageName `

| Add-AzureProvisioningConfig –Linux -LinuxUser $user –Password $pwd -NoSSHEndpoint `

| New-AzureVM –ServiceName $ServiceName -Location $Location

Open the required ports and map them

Get-AzureVM -ServiceName $ServiceName -Name $ServiceName `
| Add-AzureEndpoint -Name "SSH" -LocalPort 22 -PublicPort $SSHPort -Protocol tcp `

| Add-AzureEndpoint -Name "StatsDInput" -LocalPort 8125 -PublicPort $StatsDInputPort -Protocol udp `

| Add-AzureEndpoint -Name "StatsDAdmin" -LocalPort 8126 -PublicPort $StatsDAdminPort -Protocol udp `

| Add-AzureEndpoint -Name "ElasticSearch" -LocalPort 9200 -PublicPort $ElasticSearchPort -Protocol tcp `

| Update-AzureVM

Write-Host "now run: ssh $serviceName.cloudapp.net -p $SSHPort -l $user"

The whole script is in a gist here

Stage 1 complete

Now we have a shiny new VM running up in Azure, so let’s configure it for gathering metrics using a bash script.

Stage 2, Installing the metrics software

You could probably have the powershell script automatically upload and execute this, but it’s no big deal to SSH in, “sudo nano/vi” a new file, paste it in, chmod, and execute the below.

Set up the prerequisites

# Prerequisites
echo "#### Starting"
echo "#### apt-get updating and installing prereqs"
sudo apt-get update
sudo apt-get install screen libexpat1-dev libicu-dev git build-essential curl -y

Install nodejs

# Node
echo "#### Installing node"
. ~/.bashrc
export "PATH=$HOME/local/bin:$PATH"
mkdir $HOME/local
mkdir $HOME/node-latest-install

pushd $HOME/node-latest-install
 curl http://nodejs.org/dist/node-latest.tar.gz | tar xz -strip-components=1
 ./configure -prefix=~/local
 make install
popd

## the path isn't always correct, so set up a symlink
sudo ln -s /usr/bin/nodejs /usr/bin/node

## nodemon
echo "#### npming nodemon"
sudo apt-get install npm -y
sudo npm install -g nodemon

Add StatsD

Here I’ve configured it to use mongo-statsd-backend as the only backend and not graphite. Configuring Graphite is a PAIN as you have to set up python and a web server and deal with all the permissions, etc. Gah.

# StatsD
echo "#### installing statsd"
pushd /opt
 sudo git clone https://github.com/etsy/statsd.git
 cat >> /tmp/localConfig.js << EOF
{
 port: 8125
, dumpMessages: true
, debug: true
, mongoHost: 'localhost'
, mongoPort: 27017
, mongoMax: 2160
, mongoPrefix: true
, mongoName: 'statsD'
, backends: ['/opt/statsd/mongo-statsd-backend/lib/index.js']
}
EOF

 sudo cp /tmp/localConfig.js /opt/statsd/localConfig.js
popd

Mongo and a patched mongo-statd-backend

You could use npm to install mongo-statsd-backend, but that version has a few pending pull requests to patch a couple of issues that mean it doesn’t work out of the box. As such, I use my own patched version and install from source.

# MongoDB
echo "#### installing mongodb"
sudo apt-key adv -keyserver hkp://keyserver.ubuntu.com:80 -recv 7F0CEB10
echo 'deb http://downloads-distro.mongodb.org/repo/ubuntu-upstart dist 10gen' | sudo tee /etc/apt/sources.list.d/mongodb.list
sudo apt-get update && sudo apt-get install mongodb-org -y
sudo service mongod start
cd /opt/statsd

## Mongo Statsd backend - mongo-statsd-backend
## the version on npm has issues; use a patched version on github instead:
sudo git clone https://github.com/rposbo/mongo-statsd-backend.git
cd mongo-statsd-backend
sudo npm install

Ready to start?

Let’s kick off a screen

# Start StatsD
screen nodemon /opt/statsd/stats.js /opt/statsd/localConfig.js

Fancy getting ElasticSearch in there too?

To pull down and install the java runtime, install ES and the es-head, kopf, and bigdesk plugins, add the below script just before you kick off the “screen” command.


# ElasticSearch
echo "#### installing elasticsearch"
sudo apt-get update && sudo apt-get install default-jre default-jdk -y
wget https://download.elasticsearch.org/
elasticsearch/elasticsearch/elasticsearch-1.1.1.deb && sudo dpkg -i elasticsearch-1.1.1.deb
sudo update-rc.d elasticsearch defaults 95 10
sudo /etc/init.d/elasticsearch start

## Elasticsearch plugins
sudo /usr/share/elasticsearch/bin/plugin -install mobz/elasticsearch-head
sudo /usr/share/elasticsearch/bin/plugin -install lukas-vlcek/bigdesk

You can now browse to /_plugin/bigdesk (or the others) on the public $ElasticSearchPort port you configured in the powershell script to see your various ES web interfaces.

The whole script is in a gist here.

Stage 2 complete

I use StatsD to calculate a few bits of info around the processing of common tasks, in order to find those with max figures that are several standard deviations away from the average and highlight them as possible areas of concern.

I have an Azure Worker Role to pull azure diagnostics from table and blob storage and spew it into the Elasticsearch instance for easier searching; still figuring out how to get it looking pretty in a Grafana instance though – I’ll get there eventually.

$’\r’: command not found

Working between Windows and Linux machines can be liberating, but a bit of a pain at times. One of these times is when creating scripts on a Windows PC and copying them over to a Linux box only to receive “$’\r’: command not found” when attempting to execute them.

This is due to the files being saved in DOS format where new lines are delimited with \r\n as opposed to the *nix \n format.

You can either ensure the files are saved in Unix format in your Win text editor, or even use this extremely easy method to process them on the Linux box:

sudo apt-get install dos2unix
....
sudo dos2unix <your filename here>

Easy.

Headless VirtualBox

VirtualBox

I tend to create a lot of proofs of concept, be it applications or servers, and this process will usually start with spinning up a VM. For this I prefer to use Oracle’s VirtualBox mainly because it’s free and easy to use.

However, using VirtualBox each time I want to start and stop the VM isn’t great as it will open up the VM in a new window and you need to have both the VM window and VirtualBox running on your machine at the same time.

Luckily you can use the “start” command to run VirtualBox’s VBoxHeadless application to boot up a VM without starting VirtualBox itself and without having a window open, other than the command line.

start "Build Server VM" /D"C:\Program Files\Oracle\VirtualBox\" /MIN VBoxHeadless.exe --startvm "Server 2008 32"

Just make sure the name of the VM at the end of the command is the same as that within VirtualBox:

VirtualBox dashboard

You can then access this via RDP (if your VM is windows) or SSH (if it’s Linux), as can anyone else on your network, should you have configured its network settings correctly.