Presign

Generates the pre-signed URL for a staged file by the stage name and file path you provide. The pre-signed URL enables you to access the file through a web browser or an API request.

tip

When using cURL to interact with non-S3-like storage, remember to include the headers generated by the PRESIGN command for secure file uploads or downloads. For example,

curl -H "<header-generated-by-presign>" -o books.csv <presigned-url>

curl -X PUT -T books.csv -H "<header-generated-by-presign>" <presigned-url>

See also:

• Presign RFC
• LIST STAGE FILES: Lists files in a stage.
• REMOVE STAGE FILES: Removes files from a stage.

Syntax

PRESIGN [ { DOWNLOAD | UPLOAD }] @<stage_name>/.../<file_name> [ EXPIRE = <expire_in_seconds> ]

Where：

[ { DOWNLOAD | UPLOAD }]: Specifies that the pre-signed URL is used for download or upload. The default value is DOWNLOAD.

[ EXPIRE = <expire_in_seconds> ]: Specifies the length of time (in seconds) after which the pre-signed URL expires. The default value is 3,600 seconds.

Examples

Generating and Using Pre-signed URLs for Download

This example generates the pre-signed URL for downloading the file books.csv on the stage my-stage:

PRESIGN @my_stage/books.csv
+--------+---------+---------------------------------------------------------------------------------+
| method | headers | url                                                                             |
+--------+---------+---------------------------------------------------------------------------------+
| GET    | {}      | https://example.s3.amazonaws.com/books.csv?X-Amz-Algorithm=AWS4-HMAC-SHA256&... |
+--------+---------+---------------------------------------------------------------------------------+

This example functions in the same way as the preceding one:

PRESIGN DOWNLOAD @my_stage/books.csv

To download the file with the pre-signed URL and save it as books.csv, execute the following command:

curl <presigned-url> -o books.csv  

This example generates the pre-signed URL that expires in 7,200 seconds (2 hours):

PRESIGN @my_stage/books.csv EXPIRE = 7200

Generating and Using Pre-signed URLs for Upload

This example generates the pre-signed URL for uploading a file as books.csv to the stage my_stage:

PRESIGN UPLOAD @my_stage/books.csv

To upload the file books.csv with the pre-signed URL, execute the following command:

curl -X PUT -T books.csv <presigned-url>