vm.args is only copied from release once

[aaronjensen]

At the moment it seems that vm.args is (intentionally?) copied from the release directory to running-config only the first time. After that, it is no longer copied regardless of whether or not you upgrade, switch to a new version, etc. This is a surprising behavior because conform config copies every time boot is run (which actually wasn't the case). Should we treat vm.args the same way?

[bitwalker]

Yes, vm.args should be treated the same way. We'll need to make sure the boot script does that.

[bitwalker]

Per our conversation on IRC, here's my findings/suggested fix for this in exrm:

• Currently, sys.config in running-config is always overwritten when generate_config is called. This is not how I want running-config to operate. This isn't an issue with conform, as config changes are made in the .conf. We want running-config to be persistent so that custom configuration can be done there.
• vm.args in running-config is only created the first time, and other than deleting it, there's no way to get the vm.args from the release package there. The persistence is desired, but there needs to be an escape hatch.

My suggested/planned fix for this: Define a new environment variable PERSISTENT_RUNNING_CONFIG. When set, sys.config and vm.args in running-config will never be overwritten with versions in the release package, with the exception of when using conform, where sys.config will still be overwritten. When unset, sys.config and vm.args will always be overwritten by their counterparts in the release package (basically the current behaviour, except vm.args will also be overwritten after this change).

Any feedback on this proposed change is welcome from all :)