The NodePing API and PowerShell

At NodePing we interact with our own API quite a bit from the command line.  Most of that is from bash on Linux, because that’s where we live most of our lives.  But the API works well from just about any scripting environment.  Since our documentation examples all use curl with bash syntax, it seemed like it might be a good idea to also write up some examples of using other tools.  Here, as the first installment of that effort, is a handful of examples of using PowerShell with the NodePing API.

Full disclosure: PowerShell is not an environment we spend a lot of time working with.  There are likely ways to do some of this better.  We’ve tested the example calls in this post.  Hopefully it is enough to get you started if you work with PowerShell.

Basic GET Calls

Basic calls are quite simple to make using Invoke-RestMethod.  If you have the check ID, getting a check is quite easy:

Invoke-RestMethod ‘https://api.nodeping.com/api/1/checks/201205050153W2Q4C-OJ2HSIRF?token=[token]’

This returns a JSON object, which PowerShell handles easily.

_id : 201205050153W2Q4C-0J2HSIRF
description : This is the description, if the check has one.
public : False
customer_id : 201205050153W2Q4C
queue : nyI8JSL23W
interval : 1
created : 1427513104608
pro : nodeping.com
modified : 1510332098196
parameters : @{target=https://example.com/; follow=False; threshold=5; sens=2; invert=False; verify=false}
firstdown : 0
label : Keep me
runlocations : False
enable : active
uuid : bd3eha9o-z2m5-4qg2-9k8b-jqq0kiituyxz
state : 1
status : assigned
notifications : {}
type : HTTP
acctdisable : False
suspacct : False
dep : False

Note that “parameters” is another hash.  You can refer to the fields in the check as properties of the returned object, including properties that are hashes themselves.  So, for example, this will give you the check check threshold, which is part of “parameters”.

$check = Invoke-RestMethod ‘https://api.nodeping.com/api/1/checks/201205050153W2Q4C-0J2HSIRF?token=[token]’ ;
$check.parameters.threshold;

API Authentication

PowerShell doesn’t easily support basic authentication.  Since the NodePing API supports passing the token as a parameter, the easiest approach is to include it in the query string, as I did in the example above.  In most cases I prefer to pass it in the Body, as I’ll show in examples below.  If you’re working with a script its usually easiest to set a $token variable and use that throughout your script.  If you’re just sending a URL as I did in the simple GET calls above, actually putting in the query string works fine.

If you’re using the API in scripts that make several calls to the API, you might want a more reusable way to pass the token that keeps it out of your Body.  You can do this by manually building the headers.  That requires base64 encoding the credentials and then setting that using the -Headers argument. That looks something like this:

$hash = [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(("{0}:{1}" -f $token,"")))

Then set the -Header argument to @{Authorization=(“Basic {0}” -f $hash)}

Or, if you are doing this several times, you will probably want to set this to a variable you can reuse.

Some sites suggest that you create a credential object using ConvertTo-SecureString and Management.Automation.PSCredential, and pass that using the -Credential argument.  However, this won’t work with the NodePing API, since the -Credential option waits for the challenge to send the authorization header.  The API is stateless, and expects the header on each request.

Put and Post Calls

We recommend that you use JSON to set fields for our API in most environments.  However, PowerShell does not automatically handle sending the body as JSON.  For POST calls, this isn’t a big deal, and you can just POST the body as it is and Invoke-RestMethod sends the data as if it were a form.  PUT and DELETE calls don’t work that way.  For those, you have to convert to JSON, or include all of your parameters in a query string.

Creating a check looks like this:

Invoke-RestMethod 'https://api.nodeping.com/api/1/checks' -Method Post -Body @{ 
    label='test label' 
    type="HTTP"
    target="http://example.com"
    token=$token 
}

This call will return an object with the new check.  You can add any of the other fields listed in our documentation.

Updating a check is almost the same.  This can all be done on one line, but we’ll split it out here to make it easier to see.

$data = @{ label='a new label'; type="HTTP"; interval=5; token=$token } | ConvertTo-Json
Invoke-RestMethod 'https://api.nodeping.com/api/1/checks/201205050153W2Q4C-0J2HSIRF' -Method Put -Body $data

Note that since we’re updating a check, we need to include the check ID.  As with the Post call, the Put call returns the updated check object.

Working with Lists of Checks

Working with a list of checks is slightly trickier.  The call returns a JSON object with a list of checks using the ID as the key.  For PowerShell, this is a hash table of hashes.  So to list checks, you would do something like this:

Invoke-RestMethod 'https://api.nodeping.com/api/1/checks' -Body @{ token=$token } | %{ $_.PSOBJECT.Properties.value }

This is actually fairly handy, because you can fairly easily list a specific field from the response.  For example, this lists all of the targets from all of the checks on this account:

Invoke-RestMethod 'https://api.nodeping.com/api/1/checks' -Body @{ token=$token } | %{ $_.PSOBJECT.Properties.value.parameters.target }

You could do all sorts of things at this point.  For example, here’s a list of all checks that include “nodeping” somewhere in the check’s target:

Invoke-RestMethod 'https://api.nodeping.com/api/1/checks' -Method Get -Body @{ token=$token } | %{ foreach($value in $_.PSOBJECT.Properties.value){ if($value.parameters.target -like "*nodeping*"){ $value } } }

This is practical as a way to find a check with a specific target up to a few thousand checks.

Getting Results

Applying the same principles should let you do just about anything with the NodePing API.  Applying the same pattern to a results call, for example:

Invoke-RestMethod 'https://api.nodeping.com/api/1/results/201205050153W2Q4C-0J2HSIRF' -Method Get -Body @{ token=$token; limit=2; clean=1 }

Note that you’ll want to always include the “clean” parameter for results.  The unclean response takes more parsing.

The options available for results calls are documented here:
https://nodeping.com/docs-api-results.html

Profit!

That’s the basics of using PowerShell to interact with the NodePing API.  With the API you can add checks, remove checks, get your results and uptime, manage contacts and notifications, and add and manage subaccounts.  Our customers use the API both for programmed integrations, and from the command line using quick scripts like the ones I demonstrated here to make quick changes to several (or lots) of checks at once.

If you’re doing interesting things with PowerShell and the NodePing API, we’d like to hear about it!  Please email support and let us know.  That’s also a great place to ask us questions.  We’re happy to help people interact with our service.