Uploading and Downloading Files

Laminar provides mechanisms for handling binary data (files) within your workflows, particularly in conjunction with HTTP requests and shell scripts.

When an http request (using lam.httpRequest) results in a file download, Laminar automatically stores the file and provides a binaryDataId in the step's response.

Sample response for downloading file

{
  "lam.httpStatusCode": 200,
  "lam.httpStatusText": "OK",
  "lam.success": true,
  "lam.binaryDataIndicator": true,
  "lam.contentType": "application/zip",
  "lam.fileName": "fileName",
  "lam.contentLength": 625,
  "lam.binaryDataId": "binaryId"
}

You can access this ID via data.step_N.response['lam.binaryDataId'].

Processing files in script:

To process a downloaded file (or any binary data referenced by a binaryDataId) within a lam.shell script, you must include the binaryDataIds array in your lam.shell definition.

Laminar will make these files available to your shell script in its execution environment.

Example Workflow:

1

Download Report

(data) => {
    // This step simulates downloading a CSV report.
    return {
        "lam.httpRequest": {
            "method": "GET",
            "url": "https://mockserver.com/download-report.csv"
        }
    };
}

After this step executes, data.step_1.response['lam.binaryDataId'] will hold the reference to the downloaded CSV file.

2

Print Report

(data) => {
    // Get the binaryDataId from the previous step's response (Step 1).
    const downloadedFileId = data.step_1.response['lam.binaryDataId'];
    const fileName = data.step_1.response['lam.fileName'];

    return {
        "lam.shell": {
            // The script will operate on the downloaded file.
            // Laminar makes files referenced by binaryDataIds available by their original names
            // or a generic 'input' if no name is available.
            "script": `
                echo "Processing downloaded file..."
                # Assuming the downloaded file is named 'report.csv' or similar, or just 'input'
                # You might need to inspect the actual filename provided by Lunar in logs.
                cat ${fileName} | wc -l
            `,
            "binaryDataIds": [downloadedFileId],
        }
    };
}