Allow custom scripts to fail gracefully on errors detected by the scripts

[BarbarossaTM]

NetBox version

v3.3.9

Feature type

Change to existing functionality

Proposed functionality

It would be nice if a custom script (and I guess a report, too), would have the option to throw a special kind of Exception (say AbortScript (msg: str), which stops the script, aborts the DB transaction, and stores the error msg so the caller can see the fact that the script was aborted and why.

Happy to open a PR to add this into the _run_script() function. If there is a way to do this, which I didn't find, I'm more than happy for a pointer :-)

Use case

I wrote a scripts which should aid in provisioning things inside our network, which will do some sanity checks and if all is good set up a number of things (prefixes, IPs, sub-interfaces, IPs on them, etc.). The reason to do this inside a script is to do this in an atomic operation, so either the full provision process is done, or nothing is changed at all.

Now I was looking into exiting the script on an error and only found the option to throw any Exception which will produce a stack trace of all my internal Exceptions I caught and handled. When I throw a AbortTransaction Exception from the script I can't pass any message.

Database changes

None.

External dependencies

None.

[jeremystretch]

Sounds good. It might make sense to use the AbortRequest exception for this.

[BarbarossaTM]

Took the evening an had a look at this and it seems to be rather straight forward. What do you think @jeremystretch?