How to Upload an Attachment to Confluence Page using PowerShell and REST API?

[Boris_PS1]

Does anybody know, How to Upload an Attachment to Confluence Page using PowerShell and REST API?

I have an example on Confluence documentation on CURL:

curl -v -S -u admin:admin -X POST -H "X-Atlassian-Token: no-check" -F "file=@myfile.txt" -F 
"comment=this is my file" "http://localhost:8080/confluence/rest/api/content/3604482/child/attachment" 
| python -mjson.tool

But I'm a bit stuck on converting it to PowerShell in a correct way. 

Please advice....

[DarkSideMilk · Accepted solution]

I followed the example I found here

https://community.developer.atlassian.com/t/powershell-invoke-restmethod-uploading-new-attachment-to-jira-ticket/6184/2

The more detailed answer would involve saying that the multipart-form content type doesn't work with invoke-restmethod, at least not in the way confluence/jira needs it to.

So you use a different method that is similar, it still requires a idictionary/hash table powershell object for the headers. And it needs the api uri for the attachment of a page. 

Here, let me just show you an example complete with creating a base64 encoded string for the authorization header, formatting got messed up in copying though.

function Add-AttachmentToPage { 
    [CmdletBinding()] 
    param ( 
        [string]$baseUrl, #base url to create the api uri from, no trailing slash
        [string]$pageId, #id of the page in confluence
        [string]$filePath, #path to the file to upload
        [string]$authToken #base64 encoded string of username:password
    ) 

    begin { 
        Write-Host "creating uri and web client for file upload"
        $uri = "$baseUrl/rest/api/content/$pageId/child/attachment"; 
        $webClient = New-Object System.Net.WebClient;
        $webClient.Headers.Add('X-Atlassian-Token','no-check');
        $webClient.Headers.Add('Authorization',"Basic $authToken"); 
    }
 
    process { 
        Write-Host "Uploading $filePath confluence page of id $pageId via uri $uri"; 
        $webClient.UploadFile($uri,$filePath); 
    } 

    end { 
        Write-Host "$filePath attached to confluence page of id $pageId";
        return; 
    }
}

function Convert-StringToBase64 { 
    [CmdletBinding()] 
    param ( $Text ) 
    begin { $Bytes = [System.Text.Encoding]::Unicode.GetBytes($Text) } 
    process { $EncodedText =[System.Convert]::ToBase64String($Bytes) } 
    end { return $EncodedText }
}

$authToken = Convert-StringToBase64 -Text 'username:password';

Add-AttachmentToPage -baseUrl 'https://YOURCONFLUENCEURL' -pageId 123 -filePath '\\path\to\file' -authToken $authToken;