SAS Generator

Overview

This Snap generates a SAS (Shared Access Signature) URI that enable you to access Azure Storage containers or blobs for a specified period. You can use this URI with other Snaps, such as File Writer or File Reader , to interact with the files in the Azure Storage container or blob. See Using SAS for more information on SAS.



Depending upon the Snap's configuration, you can either access all blobs in a container, or a specific blob in a container. See Snap Settings for more information.

SAS Type Compatibility Chart

Snap Name Service SAS On Container Service SAS On Blob Account SAS
Directory Browser Yes No No
File Delete Yes Yes No
File Operation Yes No Yes
File Poller Yes No No
File Reader Yes Yes Yes
File Writer Yes Yes Yes
Multi File Reader Yes No No
Zipfile Read Yes Yes Yes
Zipfile Write Yes Yes Yes

Configuring Accounts

This Snap uses account references created on the Accounts page of the SnapLogic Manager to handle access to this endpoint. This Snap requires an Azure Storage account. See Configuring Binary accounts for information on setting up accounts that work with this Snap.

Snap views

View Description Examples of upstream and downstream Snaps
Input This Snap has at most one optional document input view. It may contain values to evaluate expression properties in SAS Generator Snap.

A document containing the key/value pairs required for populating the expression properties in the Snap.

Output This Snap has exactly one output view.
A document containing two fields, SasType and SasUri. The following is a sample output document:
{
“SasType” : “Service SAS on container”,

“SasUri”  : “https://snapqa.blob.core.windows.net/testdata?sig=lnqwQPgOKtN1dm1

CHV5cPxUDBHuxOkYz0nWkq%2Fz9dBI%3D&st=2019-06-25T19%3A59

%3A03Z&se=2019-06-25T20%3A09%3A03Z&sv=2018-11-09&sp=rwdl

&sr=c"

}
Error

Error handling is a generic way to handle errors without losing data or failing the Snap execution. You can handle the errors that the Snap might encounter when running the pipeline by choosing one of the following options from the When errors occur list under the Views tab. The available options are:

  • Stop Pipeline Execution Stops the current pipeline execution when an error occurs.
  • Discard Error Data and Continue Ignores the error, discards that record, and continues with the remaining records.
  • Route Error Data to Error View Routes the error data to an error view without stopping the Snap execution.

Learn more about Error handling in Pipelines.

Snap settings

Legend:
  • Expression icon (): Allows using pipeline parameters to set field values dynamically (if enabled). SnapLogic Expressions are not supported. If disabled, you can provide a static value.
  • SnapGPT (): Generates SnapLogic Expressions based on natural language using SnapGPT. Learn more.
  • Suggestion icon (): Populates a list of values dynamically based on your Snap configuration. You can select only one attribute at a time using the icon. Type into the field if it supports a comma-separated list of values.
  • Upload : Uploads files. Learn more.
Learn more about the icons in the Snap settings dialog.
Field / Field set Type Description
Label String

Required. Specify a unique name for the Snap. Modify this to be more appropriate, especially if more than one of the same Snaps is in the pipeline.

Default value: SAS Generator

Example: SAS Generator
Container String/Expression/ Suggestion The name of the Azure Storage container that you want to access. Enter the name or select one suggested by the Snap. This property is required for Service SAS on container and Service SAS on blob.
Warning: The container's name must always be in lowercase. See Referencing Containers and Blobs for more information.

Default value: N/A

Example: testcontainer
Blob String/Expression/ Suggestion The name of the Azure Storage blob that you want to access. Enter the name or select one suggested by the Snap. Blob name should be a relative path in the container.
Warning: Leave this property blank to access all the blobs in the specified container.

Default value: N/A

Example:
  • testblob
  • abc.csv
  • testblob/abc.csv
Protocol Dropdown list The protocol over which Azure Storage permits access to the client using the SAS URI. Available options are:
  • https: For WASBS
  • http: For WASB

Default value: https
SAS Permissions Select the file-access permissions that you want to assign to users of the SAS URI. See Specifying Permissions for more information.
Read Dropdown list Permission to read a blob.

Default value: READ
Write Dropdown list Permission to create or overwrite a blob.

Default value: WRITE
List Dropdown list Permission to list a directory

Default value: LIST
Create Dropdown list Permission to create a blob (cannot overwrite an existing blob)

Default value: CREATE
Delete Dropdown list Permission to delete a blob.

Default value: DELETE
Expire in (hours) Integer/Expression Specifies the validity of the SAS URI in hours. Configure this property and the Expire in (minutes) property to specify the total duration of the URI's validity.

Minimum value: 0

Example: 3

Default value: 0
Expire in (minutes) Integer/Expression Specifies the expire time in minutes.

Minimum value: 0

Default value: 1

Example: 10
Snap execution Dropdown list
Choose one of the three modes in which the Snap executes. Available options are:
  • Validate & Execute: Performs limited execution of the Snap and generates a data preview during pipeline validation. Subsequently, performs full execution of the Snap (unlimited records) during pipeline runtime.
  • Execute only: Performs full execution of the Snap during pipeline execution without generating preview data.
  • Disabled: Disables the Snap and all Snaps that are downstream from it.

Default value: Execute only

Example: Validate & Execute

Understanding the SAS URI Validity

The validity of the SAS URI is determined by the values in the Expire in (hours) and Expire in (minutes) properties. For example, if the SAS Generator Snap is configured as shown below, the validity of the SAS URI generated by the Snap is 3 hours and 43 minutes.