Porto layers

This section contains information about Porto layers.

Terminology

• A Porto layer is a fragment of an image of a root file system for Porto;
• A RootFS Image is an image of a root file system;
• A base layer(base image) is an autonomous layer that contains the main part of the ambient scene (/bin/bash, libc6, etc.); by selecting a base layer, you are confirming the Ubuntu version (Precise, Trusty, Xenial, Bionic, etc.) your code will be working in.
• A Delta layer is a layer that supplements the base image and usually contains additional libraries or binary artifacts.

Using layers to launch operations in YTsaurus

A MapReduce operation must be launched in Porto layers if its execution requires libraries or resources that aren't available in YTsaurus clusters, and if there is no way to prepare a binary file with this operation.

To use Porto layers, in the operation specifications in the mapper or reducer section, you must indicate layer_paths = ["//path/to/upper_layer"; ... ; "//path/to/lower_layer"]. Layers are listed from top to bottom.

Standard and cached images are stored in YTsaurus clusters. Using a task in Sandbox, you can also create layers with libraries and upload them right to Cypress, along with the dependent images.