Archive | ShellScript

Code to query Azure Load Balancer Metrics to verify Availability (VipAvailability )

This one was fun to put together.

I wanted to write code to query the status of an Azure Load Balancer. I couldn’t find much out there. This code query’s the Azure Load Balancer’s Metrics for VipAvailability – through the REST API. If it returns 100 then are good to go. Anyting else, then there may be a issue. You can query any metric, and you can set a time range, I am just looking at the last min.

Note: This is for a Standard Load Balancer, not Basic.

Some of the Metrics Available:

VipAvailability : Average count of availability of VIP endpoints, based on probe results.
DipAvailability : Average count of availability of DIP endpoints, based on probe results.
ByteCount : Total number of bytes processed per front-end.
PacketCount : Total number of packets processed per front-end.
SynCount : Total number of SYN packets received.
SnatConnectionCount : Total number of new SNAT connections, that is, outbound connections that are masqueraded to the Public IP address front-end.

And the same metrics are often referred to by different names (this was confusing to me):

value               localizedValue                
-----               --------------                
VipAvailability     Data Path Availability        
DipAvailability     Health Probe Status           
ByteCount           Byte Count                    
PacketCount         Packet Count                  
SYNCount            SYN Count                     
SnatConnectionCount SNAT Connection Count         
AllocatedSnatPorts  Allocated SNAT Ports (Preview)
UsedSnatPorts       Used SNAT Ports (Preview) 

Here is the code (bouns: BASH/cURL too) to find the VipAvaiablity of Azure Load Balancers:

$SubscriptionId = "$($env:SubscriptionId)"
$TenantId       = "$($env:TenantId)" 
$ClientID       = "$($env:ClientID)"      
$ClientSecret   = "$($env:ClientSecret)"  
$TenantDomain   = "$($env:TenantDomain)" 
$loginURL       = "$TenantId/oauth2/token"
$resource      = "" 
$resourceGroupName = "eastUS-01"
$body           = @{grant_type="client_credentials";resource=$resource;client_id=$ClientID;client_secret=$ClientSecret}
$oauth          = Invoke-RestMethod -Method Post -Uri $loginURL -Body $body
$headerParams = @{'Authorization'="$($oauth.token_type) $($oauth.access_token)"}

$filter = "(name.value eq 'VipAvailability') and aggregationType eq 'Average' and startTime eq $start and endTime eq $end and timeGrain eq duration'PT1M'"
$url = "$SubscriptionId/resourceGroups/$resourceGroupName/providers/Microsoft.Network/loadBalancers/jemurphyLB01/providers/microsoft.insights/metrics?`$filter=${filter}&api-version=2016-09-01"
$results=Invoke-RestMethod -Uri $url -Headers $headerParams -Method Get
$results.value | select -ExpandProperty data | select timestamp,average


TOKEN=$(curl --silent --request POST $LOGINURL --data-urlencode "resource=" --data-urlencode "client_id=$CLIENTID" --data-urlencode "grant_type=client_credentials" --data-urlencode "client_secret=$CLIENTSECRET" | jq -r '.access_token')

STARTTIME=$(date -u +'%Y-%m-%dT%H:%M:00' --date='-1 min')
ENDTIME=$(date -u +'%Y-%m-%dT%H:%M:00')

FILTER="(name.value eq 'VipAvailability') and aggregationType eq 'Average' and startTime eq $STARTTIME and endTime eq $ENDTIME and timeGrain eq duration'PT1M'"

RESULTS=$(curl -s -G --header "authorization: Bearer $TOKEN" --data-urlencode "\$filter=$FILTER" --data-urlencode "api-version=2016-09-01" $URL | jq .value[].data[].average)

echo "$RESULTS"

I think the hardest part was trying to get the date and time in the right format. Why is that so hard?

This HAS to be helpful to some one!


Note to self: cURL with data-urlencode for GET/QuerySting values

I know I would loose this if I didn’t blog it.
With cURL, you can use “–data-urlencode” with query string params and a GET if you include the “-G” parameter. Of course you still have to escape things out, I just found it easer to add all the QueryString params separately. All the examples I could find were for POSTs.

FILTER="ReallyLongStringWIth"$VARS" SPACES and ' SINGLE quotes and a &"
curl -s -G --header "authorization: Bearer $TOKEN" --data-urlencode "\$filter=$FILTER" --data-urlencode "api-version=2016-09-01" $URL 


Using git and a post-recive to update production node.js apps.

I have been trying to figure out the best way to deploy and maintain node.js apps in development and production. If I have a local git repo on my machine, and I want to push it to production, what is the best way to do this? I don’t think the .git files should be there. I also don’t keep my modules in the repo, so I need a way to push updates, and make sure the newest dependencies are on the server.
I figured out that people are using a post-recieve script to update the site. This is what I ended up with. You put it in a file named post-receive in the hooks folder (on the server not on your local repo)

git --work-tree=$GIT_WORK_TREE checkout --force
npm install

I may take this a step further and recycle pm2, but that is another post!


Connecting to the Salesforce REST api using cURL

My company decided to use Salesforce. I have worked with Microsoft CRM, but not Salesforce yet. When learning about a new application, I like to see how I can access the data. PowerShell and cURL are the simplest way for me to understand how to connect to a REST api.

First step is getting an OAuth2 token. This is well documented, but being new to the platform, I needed to start from the beginning.

First you need to create an app. Copy the ID and the Secret (I am using lightning):

Setup Home -> Platform Tools -> Expand Apps -> Apps -> Connected Apps -> New. You can follow these directions

After it is created, you need to create a token for the user:

Top menu on upper right corner click on your “icon” -> Settings -> My Personal Information – Reset My Security Token.
Click reset and it will be emailed to you.

Here is the cURL command to make the connection and get the access_token:

response=$(curl -s -d "grant_type=password" \
-d "client_id=ReallyLongClientIDReallyLongClientIDReallyLongClientIDReallyLongClientIDReallyLongCli" \
-d "client_secret=1234567890123456789" -d "" \
-d "password=PasswordAndTokenNoSpaces")
ACCESS_TOKEN=$(echo $response | awk -F"," '{print $1}' | awk -F":" '{print $2}' | sed s/\"//g | tr -d ' ')

Things to note: I am using my instance ID in the url. There was mixed documentation as to use this address or the standard logon url. This worked, and with the PowerShell command in the next post it was necessary. Https is required, and the password is a mashup of user name and security token

And the code to pull some data using the token

curl -H "Authorization: Bearer $ACCESS_TOKEN" -H "X-PrettyPrint:1" ""

This was pretty easy as there are many examples out there. PowerShell, not so much.


Raspberry Pi, Raspbian Jessie (based on Debian Jessie) disable AutoLogin GUI & Console

I did NOT want my Raspbian Jessie install to automatically boot into the GUI, and I did Not want it to autologin.

I know I can run raspi-config to change it, but I like to script things! I finally tracked down the code for the new raspi-config that supports systemd. It can be found here .

Here are the commands to change what used to be the run level.


systemctl set-default
ln -fs /lib/systemd/system/getty@.service /etc/systemd/system/

Console Autologin

systemctl set-default
ln -fs /etc/systemd/system/autologin@.service /etc/systemd/system/


systemctl set-default
ln -fs /lib/systemd/system/getty@.service /etc/systemd/system/
sed /etc/lightdm/lightdm.conf -i -e "s/^autologin-user=pi/#autologin-user=/"

Desktop AutoLogin

systemctl set-default
ln -fs /etc/systemd/system/autologin@.service /etc/systemd/system/
sed /etc/lightdm/lightdm.conf -i -e "s/^#autologin-user=.*/autologin-user=pi/"


Hope that helps someone.

BASH script to change the Security Keys and SALTs in a wp-config.php file

I wanted to automatically change the Security Keys/SALTS when provisioning a new WordPress site. has a service that spits back random values. ( The script below CURLs the values and then modifies a wp-config.php file with the new random values.

SALTS=$(curl -s
while read -r SALT; do
SEARCH="define('$(echo "$SALT" | cut -d "'" -f 2)"
REPLACE=$(echo "$SALT" | cut -d "'" -f 4)
echo "... $SEARCH ... $SEARCH ..."
sed -i "/^$SEARCH/s/put your unique phrase here/$(echo $REPLACE | sed -e 's/\\/\\\\/g' -e 's/\//\\\//g' -e 's/&/\\\&/g')/" /Path/To/Your/wp-config.php
done <<< "$SALTS"

Don’t remember where I got the pieces of this, but here it is, I have been using it for a while and it seems to work well.
Hope that helps someone.

Installing WordPress via shell script(BASH)

We have been using a provisioning script that downloads the latest wordpress zip file, extracts into the right location it and sets up the DB connection. I wanted to take it a step further and eliminate the install.php page. The one that looks like this:Screen_Shot_2013-03-06_at_3.54.19_PM-2


So i sat down to figure out how to “Install WordPress” via shell script. Here is that command:

wp_install_result=$(php -r 'define("WP_SITEURL", "http://'$SITENAME.$DOMAINNAME'");define("WP_INSTALLING", true);require_once("./wp-load.php");require_once("wp-admin/includes/upgrade.php");$response=wp_install("TITLE", admin, "", false, null, "'$PASSWORD'");echo $response;')

After WordPress is “installed”, we can now activate plugins.

Activating and deactivating WordPress plugins from a shell script (BASH)

I needed to update my WordPress site provisioning script to download, install and activate a WordPress plugin. The download is the easy part (I just use wget). But how do I activate the plugin. This is what I cam up with:

result=$(php -r 'require_once("./wp-load.php");require_once("wp-admin/includes/admin.php");activate_plugin("hello.php");')

And to be complete, to deactivate:

result=$(php -r 'require_once("./wp-load.php");require_once("wp-admin/includes/admin.php");deactivate_plugins("hello.php");')

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