Setup: A pretty standard data export SSIS package (SQL Server 2016 compatible), created in VS2019/Data Tools and deployed using the SSIS Project Deployment model to the Integration Services Catalog of a SQL Server 2016 instance. The package creates files in a network folder before sending the file out via FTP and putting a copy of the file in a Sent folder.
The project requirements include having the package running on a schedule using "default" parameter values, as well as allowing users to manually run the package using "non-default" parameter values from within a stand-alone application.
Current behavior: the package behaves correctly when run from a SQL Server Agent Job that is configured with a SQL proxy and credentials mapped to a domain login with the proper permissions for the network folder.
Problem: the Data Flow task fails to create the file with a "Cannot open the datafile" error when running the package directly using any of the following methods (even when the "current" session is using the same credentials as the SQL Server Credentials/Proxy used by the SQL Server Agent Job):
As far as I'm aware, these are the only methods capable of starting a SSIS package and changing the package's parameter values. I either need to get one of the latter 2 methods to work, find another option that allows for changing the parameter values while launching the package, or use one of 2 techniques I'm aware of (detailed below) that would add yet another failure point to the process as well as other potential issues.
Note: If the process is changed to initially create the file on the SQL Server's local harddrive, then the Data Flow task succeeds, but the later copy to Sent folder task fails with a very similar permissions error.
Alternative #1: this technique requires creating a new table, loading the parameter values to the table, changing the package to check the table and potentially set it's parameters/variables based on what it finds. The package can then be launched using a SQL Server Agent Job (for which there are multiple methods to manually launch them) and if the calling object has correctly populated the table, the package will behave as if it's parameters were changed at runtime otherwise it will run with the default values.
Alternative #2: Change all folders used by the package to point to folders local to the SQL Server instance and then create a separate scheduled task/application/whatever, with the valid credentials, that would synchronize or move the files to their proper network folders.
even when the "current" session is using the same credentials as the SQL Server Credentials/Proxy used by the SQL Server Agent Job
This is probably because the account is not logged on locally at the SQL Server, and so it's a Double-Hop Impersonation scenario, and would require Kerberos Constrained Delegation to be configured.
And you are correct in assessing the options. The general solution is to invoke catalog.start_execution from a session running on the SQL Server, and an Agent Job is the simplest built-in way to do this (the others being xp_cmdshell, Service Broker Activation, or SQL CLR).