cache.py

import os
import pathlib

from ruamel.yaml import YAML

from . import schema

yaml = YAML()


def configuration_from_file(file, mount):
    with file.open() as fid:
        # load the raw yaml input
        raw = yaml.load(fid)

        # validate the yaml
        schema.CacheValidator.validate(raw)

        # verify that the root path exists
        path = pathlib.Path(os.path.expandvars(raw["root"]))
        if not path.is_absolute():
            raise FileNotFoundError(f"The build cache path '{path}' is not absolute")
        if not path.is_dir():
            raise FileNotFoundError(f"The build cache path '{path}' does not exist")

        raw["root"] = path

        # Put the build cache in a sub-directory named after the mount point.
        # This avoids relocation issues.
        raw["path"] = pathlib.Path(path.as_posix() + mount.as_posix())

        # verify that the key file exists if it was specified
        key = raw["key"]
        if key is not None:
            key = pathlib.Path(os.path.expandvars(key))
            if not key.is_absolute():
                raise FileNotFoundError(f"The build cache key '{key}' is not absolute")
            if not key.is_file():
                raise FileNotFoundError(f"The build cache key '{key}' does not exist")
            raw["key"] = key

        return raw


def generate_mirrors_yaml(config, out):
    path = config["path"].as_posix()
    mirrors = {
        "mirrors": {
            "alpscache": {
                "fetch": {
                    "url": f"file://{path}",
                },
                "push": {
                    "url": f"file://{path}",
                },
            }
        }
    }

    yaml = YAML()
    yaml.default_flow_style = True
    yaml.dump(mirrors, out)