APP-7995: Don't allow two module configs to point to same ExePath

[michaellee1019]

Abe and I found a situation where if two modules point to the same ExePath, the module will be loaded twice and neither will work. This validation check will error on adding the 2nd module from the config when the ExePath exists.

For example this config is currently an issue:

    {
      "type": "registry",
      "name": "michaellee1019_gpio-flicker_from_reload",
      "module_id": "michaellee1019:gpio-flicker",
      "version": "latest-with-prerelease",
      "reload_path": "/root/.viam/packages-local/michaellee1019_gpio-flicker_from_reload-bin-module.tar.gz",
      "reload_enabled": true
    },
    {
      "type": "local",
      "name": "michaellee1019_gpio-flicker_from_reload-local",
      "executable_path": "/root/.viam/packages-local/michaellee1019_gpio-flicker_from_reload-bin-module.tar.gz"
    }

Tested on a machine in my personal org https://app.viam.com/machine/9dca9f1a-2517-49ee-806e-7c72ec022d5d/configure/builder

4/9/2025, 10:34:58 AM error rdk.resource_manager   impl/resource_manager.go:1143   error adding modules   error An existing module michaellee1019_gpio-flicker_from_reload-local already exists with the same executable path as module michaellee1019_gpio-flicker_from_reload

4/9/2025, 10:34:58 AM error rdk.modmanager.michaellee1019_gpio-flicker_from_reload   modmanager/manager.go:319   Error adding module   module michaellee1019_gpio-flicker_from_reload  error An existing module michaellee1019_gpio-flicker_from_reload-local already exists with the same executable path as module michaellee1019_gpio-flicker_from_reload

4/9/2025, 10:34:58 AM info rdk.modmanager.michaellee1019_gpio-flicker_from_reload   modmanager/manager.go:316   Now adding module   module michaellee1019_gpio-flicker_from_reload

4/9/2025, 10:34:48 AM info rdk   impl/local_robot.go:1302   Robot (re)configured

And the first module that is loaded works fine.

[abe-winter]

looks good + your suite / live tests seem legit

left non-blocking design questions

[abe-winter]

does this break the entire reconfigure? or does the reconfigure loop continue for other modules

[michaellee1019]

It will only stop reconfigure for this module. The reconfigure loop is higher up in the stack, this method is called for each module in the case where there are multiple modules being reconfigured.

So this one module would error, and the existing module that is already configured with the same exepath will keep running.

[abe-winter]

this is happening in reconfigure. thinking through the broader flow here:

• I create module 1
• I create module 2 with same exe path
• module 2 fails to add()
• now I reconfigure module 1
• does it error, leaving zero working copies? or is module 2 not in mgr.modules, because it failed to add()?

[michaellee1019]

Good question. the 2nd module will never be added to mgr.modules in add(). An error is returned during this validation before it is attempted to be started and added to mgr.modules.

So in the case you brought up, module 1 will be added, module 2 will not, when module 1 is reconfigured it will pass this validation because it has no awareness that module 2 is failing to be added.

[michaellee1019]

I also did a another round of manual testing and ensured this is the case. Didn't see this issue or anything else in the various scenarios I tested.

[michaellee1019]

TY for the quick review!