Invoke-CosmosDbQuery.ps1

<#
.SYNOPSIS
    Query a CosmoDb.

.DESCRIPTION
    This command will query a cosmos db and return the results as an object.

.PARAMETER EndPoint
    The endpoint to the CosmosDb Account.

.PARAMETER DatabaseId
    The database to issue the query to.

.PARAMETER CollectionId
    The collection to query.

.PARAMETER Key
    The key used to access the CosmosDb database account.

.PARAMETER Query
    The query to run

.EXAMPLE
    Invoke-CosmosDbQuery -EndPoint https://my-cosmos-db.documents.azure.com:443/ -DatabaseId MyDatabase -CollectionId authDocuments -Key asdf1234 -Query "SELECT * from c"
#>
function Invoke-CosmosDbQuery
{
    [CmdletBinding()]
    Param
    (
        [Parameter(Mandatory=$true)][String]$EndPoint,
        [Parameter(Mandatory=$true)][String]$DatabaseId,
        [Parameter(Mandatory=$true)][String]$CollectionId,
        [Parameter(Mandatory=$true)][String]$Key,
        [Parameter(Mandatory=$true)][String]$Query
    )

    function GenerateSignature([String]$resourceLink, [String]$dateTime, [String]$key)
    {
        $hmacSha256 = New-Object System.Security.Cryptography.HMACSHA256
        $hmacSha256.Key = [System.Convert]::FromBase64String($key)

        $payLoad = "post`ndocs`n$resourceLink`n$($dateTime.ToLowerInvariant())`n`n"
        $hashPayLoad = $hmacSha256.ComputeHash([System.Text.Encoding]::UTF8.GetBytes($payLoad))
        $signature = [System.Convert]::ToBase64String($hashPayLoad);

        [System.Web.HttpUtility]::UrlEncode("type=master&ver=1.0&sig=$signature")
    }

    $ResourceLink = "dbs/$DatabaseId/colls/$CollectionId"

    $dateTime = [DateTime]::UtcNow.ToString("r")
    $authHeader = GenerateSignature -resourceLink $ResourceLink -key $Key -dateTime $dateTime
    $queryJson = @{query=$Query} | ConvertTo-Json -Compress
    $header = @{authorization=$authHeader;"x-ms-documentdb-isquery"="True";"x-ms-version"="2017-02-22";"x-ms-date"=$dateTime}
    $contentType= "application/query+json"
    $queryUri = "$EndPoint$ResourceLink/docs"

    Invoke-RestMethod -Method "POST" -ContentType $contentType -Uri $queryUri -Headers $header -Body $queryJson
}