Mounting file volumes for containerized Lambda running inside Greengrass v2

Question

I have my containerized Lambda function running well inside Greengrass v2.

~~I already use a file volume mounted as below~~ I was wrong, this was in fact a directory
```
            {
              "sourcePath": "/local/path/to/my/file",
              "destinationPath": "/file",
              "addGroupOwner": true,
              "permission": "rw"
            }
```

but when I try to mount additional file volumes for certain libraries I need in `/usr/lib/` it won't work. The files won't show up when listed. 
```
            {
              "sourcePath": "/local/path/to/my/library/librfidapi32.so",
              "destinationPath": "/usr/lib/librfidapi32.so",
              "addGroupOwner": true,
              "permission": "ro"
            }
```

Can you spot what I'm doing wrong? Thank you.

Accepted Answer

Answering this myself since although helpful @MichaelDombrowski-AWS's answer does not respond the original question directly.

First of all I think it's not possible to mount a file as I'm getting permission denied errors even when using a dir that does not exist:
```
error mounting "/local/path/to/my/library/librfidapi32.so" to rootfs at "/usr/zebra_lib/librfidapi32.so": mkdir /path/to/greengrass/v2/work/component-name/work/worker/2m7-vhzx_NF0BmR4iCS-VDoZAh5eZ1Ct5D5BcWk_duQ/rootfs/merged/usr/zebra_lib: permission denied. {serviceInstance=0, serviceName=component-name, currentState=STARTING}
```

The workaround was to mount the underlying directory and set LD_LIBRARY_PATH environment variable to it:
```
      "linuxProcessParams": {
        "containerParams": {
          "volumes": [
            {
              "sourcePath": "/local/path/to/my/libraries",
              "destinationPath": "/zebra_libs",
              "addGroupOwner": false,
              "permission": "ro"
            }
          ]
        }
      },
      "environmentVariables": {
        "LD_LIBRARY_PATH": "/zebra_libs"
      }
```

Answer

Hi,

When you make a new component version that has a changed DefaultConfiguration (this includes anytime you make a new Lambda component with different settings), you must use `RESET: [""]` in the deployment to use the new defaults. Reset will remove the configuration currently on the device and instead use the new default values. Default configuration is only applied when there is no configuration present (eg. you're deploying the component for the first time on a given device).

Use `MERGE` to update the configuration without making a new component version and changing the defaults.

Read more in:
- https://docs.aws.amazon.com/greengrass/v2/developerguide/troubleshooting.html#update-component-configuration-to-default-configuration
- https://docs.aws.amazon.com/greengrass/v2/developerguide/update-component-configurations.html

Cheers,

Michael

Mounting file volumes for containerized Lambda running inside Greengrass v2

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