Centralize log collection with a custom REST API

Use case

Function code

 

using namespace System.Net

# Input bindings are passed in via param block.
param($Request, $TriggerMetadata)

$logtype = $Request.Body.logtype
$logbody = $Request.Body.logbody

$customerId = ""
$sharedKey = ""

Function Build-Signature ($customerId, $sharedKey, $date, $contentLength, $method, $contentType, $resource){
    $xHeaders = "x-ms-date:" + $date
    $stringToHash = $method + "`n" + $contentLength + "`n" + $contentType + "`n" + $xHeaders + "`n" + $resource
 
    $bytesToHash = [Text.Encoding]::UTF8.GetBytes($stringToHash)
    $keyBytes = [Convert]::FromBase64String($sharedKey)
 
    $sha256 = New-Object System.Security.Cryptography.HMACSHA256
    $sha256.Key = $keyBytes
    $calculatedHash = $sha256.ComputeHash($bytesToHash)
    $encodedHash = [Convert]::ToBase64String($calculatedHash)
    $authorization = 'SharedKey {0}:{1}' -f $customerId,$encodedHash
    return $authorization
}

Function Post-LogAnalyticsData ($customerId, $sharedKey, $body, $logType){
    $method = "POST"
    $contentType = "application/json"
    $resource = "/api/logs"
    $rfc1123date = ([DateTime]::UtcNow).ToString("r")
    $contentLength = $body.Length
    $signature = Build-Signature -customerId $customerId -sharedKey $sharedKey -date $rfc1123date -contentLength $contentLength -method $method -contentType $contentType -resource $resource

    $uri = "https://" + $customerId + ".ods.opinsights.azure.com" + $resource + "?api-version=2016-04-01"
 
    $headers = @{
        "Authorization" = $signature;
        "Log-Type" = $logType;
        "x-ms-date" = $rfc1123date;
    }
 
    $response = Invoke-WebRequest -Uri $uri -Method $method -ContentType $contentType -Headers $headers -Body $body -UseBasicParsing
    return $response.StatusCode
}

$logbodyjson = ConvertTo-JSON $logbody -Depth 10

#Submit the data to the API endpoint
$params = @{
    CustomerId = $customerId
    SharedKey  = $sharedKey
    Body       = ([System.Text.Encoding]::UTF8.GetBytes($logbodyjson))
    LogType    = $LogType
}
$LogResponse = Post-LogAnalyticsData @params
$LogResponse

if($LogResponse -eq 200){
    Push-OutputBinding -Name Response -Value ([HttpResponseContext]@{
        StatusCode = [HttpStatusCode]::OK
        Body = $LogResponse
    })
}

 

Send logs via PowerShell script

Function Send-Logs(){

    param (
        [String]$LogType,
        $LogBodyList
    )
    $url="<functionurl>"
    
    $LogBodyJSON = @"
    {
        "logtype": "$LogType",
        "logbody": {}
    }
"@

    $LogBodyObject = ConvertFrom-JSON $LogBodyJSON
    Foreach($Log in $LogBodyList.GetEnumerator()){
        $LogBodyObject.logbody | Add-Member -MemberType NoteProperty -Name $log.key -Value $log.value
    }
    $Body = ConvertTo-JSON $LogBodyObject
    
    $Response = Invoke-Restmethod -uri $url -Body $Body -Method POST -ContentType "application/json"
    return $Response
}

$Logs = @{
    "<logmember1>"="<logvalue1>"
    "<logmember2>"="<logvalue2>"
}

Send-Logs -LogType "<logtype>" -LogBodyList $Logs