Build Configuration (Intermediate)

Audience: Users who need to execute commands to configure the machine before a LightningWork runs on it.

Level: Intermediate

When a LightningWork machine starts up in the cloud, it uses a lightweight operating system with essential packages pre-installed. If you need to install additional system packages or run other configuration steps before your code executes on that machine, it is possible to do so by creating a custom BuildConfig:

1. Subclass BuildConfig:

   from lightning.app import BuildConfig
   
   
   @dataclass
   class CustomBuildConfig(BuildConfig):
       def build_commands(self):
           return ["sudo apt-get install libsparsehash-dev"]
   

2. Set the build config on the LightningWork:

   from lightning.app import LightningWork
   
   
   class MyWork(LightningWork):
       def __init__(self):
           super().__init__()
   
           # Use the custom build config
           self.cloud_build_config = CustomBuildConfig()
   
           # Can also be combined with extra requirements
           self.cloud_build_config = CustomBuildConfig(requirements=["torchmetrics"])
   

Note

• When you need to execute commands or install tools that require more privileges than the current user has, you can use sudo without needing to provide a password, e.g., when installing system packages.

• The build config only applies when running in the cloud and gets ignored otherwise. A local build config is currently not supported.

Warning

Custom base images are not supported with the default CPU cloud compute. For example:

class MyWork(LightningWork):
    def __init__(self):
     super().__init__(cloud_build_config=BuildConfig(image="my-custom-image")) # no cloud compute, for example default work