Working with Dell EMC PowerFlex REST API using PowerShell - Part 1

In this article, I will explain briefly how to work with REST API exposed by PowerFlex (formerly known as ScaleIO and VxFlex OS Software) using PowerShell to manage/ monitor your PowerFlex cluster. The PowerFlex REST API is served from the PowerFlex Gateway which allows querying information and performing actions related to PowerFlex software components. PowerFlex Gateway connects and queries master MDM, reformats the results in a RESTful manner, and passes it to a REST client.

Access to the API requires a login using Gateway username and password. A successful login returns a token, and you can use this token for later authentications for other requests. The responses or results returned are in JSON format. In the following sections, I will explain how to use PowerShell to query PowerFlex REST API and obtain relevant results.  

PowerShell uses Invoke-RestMethod cmdlet which sends HTTP/ HTTPS requests to REST web services that return rich structured data. PowerShell will format the response based on the data type. For JSON PowerShell converts the response content to objects. 

Step 1: Authentication and token generation

#Note: 192.168.11.15 is the IP of PowerFlex Gateway

$User = Read-Host -Prompt "Please enter username"

$SecurePassword = Read-Host -Prompt "Enter Password for user $user" –AsSecureString

$Credentials = New-Object System.Management.Automation.PSCredential ($user,$Securepassword)

#HTTPS Get request is invoked with credentials for authentication

$Token = Invoke-RestMethod -Uri "https://192.168.11.15:443/api/login" -Method Get -Credential $Credentials

Step 2: Create header with the token

$auth = [System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes(':'+$Token))

$global:PowerFlexAuthHeaders = @{'Authorization' = "Basic $auth"

'Content-Type' = "application/json" }

Step 3: Invoke-RestMethod

#Query all alerts in the system

$alerts = (Invoke-RestMethod -Uri "https://192.168.11.15:443/api/types/Alert/instances/" -Method Get -Headers $PowerFlexAuthHeaders)

#Query all SDSs in a PD

$all_SDS = (Invoke-RestMethod -Uri "https://192.168.11.15:443/api/instances/ProtectionDomain::3ce4af5f00000000/relationships/Sds " -Method Get -Headers $PowerFlexAuthHeaders)

#Query a specified PD

$pd01 = (Invoke-RestMethod -Uri "https://192.168.11.15:443/api/instances/ProtectionDomain::3ce4af5f00000000 " -Method Get -Headers $PowerFlexAuthHeaders)

#Query statistics of a specified PD

$pd01_stats = (Invoke-RestMethod -Uri "https://192.168.11.15:443/api/instances/ProtectionDomain::3ce4af5f00000000/relationships/Statistics " -Method Get -Headers $PowerFlexAuthHeaders)

Hope this was useful. Refer to the PowerFlex REST API Reference Guide for more details.

In the next article, I will explain how to query selected statistics/ parameters with POST method which will help you to

create custom monitoring scripts for your PowerFlex clusters.

Note:

If you are getting the below error while trying to create the token during step 1, please add the below lines of code to the

start of your script.

"Invoke-RestMethod : The underlying connection was closed: An unexpected error occurred on a send."

#Solution to above error!

add-type @"

    using System.Net;

    using System.Security.Cryptography.X509Certificates;

    public class TrustAllCertsPolicy : ICertificatePolicy {

        public bool CheckValidationResult(

            ServicePoint srvPoint, X509Certificate certificate,

            WebRequest request, int certificateProblem) {

            return true;

        }

    }

"@

[System.Net.ServicePointManager]::CertificatePolicy = New-Object TrustAllCertsPolicy

[System.Net.ServicePointManager]::SecurityProtocol = [System.Net.SecurityProtocolType]::Tls12 -bor [System.Net.SecurityProtocolType]::Tls11