aria/cli/inputs.py

# Licensed to the Apache Software Foundation (ASF) under one or more
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# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
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"""
Helpers for validating and coercing service template inputs.
"""

import os
import glob
from ruamel import yaml

from .env import logger
from .exceptions import AriaCliError


def inputs_to_dict(resources):
    """
    Returns a dictionary of inputs

    :param resources: can be:

     * list of files
     * single file
     * directory containing multiple input files
     * ``key1=value1;key2=value2`` pairs string.
     * string formatted as JSON/YAML
     * wildcard based string (e.g. ``*-inputs.yaml``)
    """
    if not resources:
        return dict()

    parsed_dict = {}

    for resource in resources:
        logger.debug('Processing inputs source: {0}'.format(resource))
        # Workflow parameters always pass an empty dictionary. We ignore it
        if isinstance(resource, basestring):
            try:
                parsed_dict.update(_parse_single_input(resource))
            except AriaCliError:
                raise AriaCliError(
                    "Invalid input: {0}. It must represent a dictionary. "
                    "Valid values can be one of:{1} "
                    "- A path to a YAML file{1} "
                    "- A path to a directory containing YAML files{1} "
                    "- A single quoted wildcard based path "
                    "(e.g. '*-inputs.yaml'){1} "
                    "- A string formatted as JSON/YAML{1} "
                    "- A string formatted as key1=value1;key2=value2".format(
                        resource, os.linesep))
    return parsed_dict


def _parse_single_input(resource):
    try:
        # parse resource as string representation of a dictionary
        return _plain_string_to_dict(resource)
    except AriaCliError:
        input_files = glob.glob(resource)
        parsed_dict = dict()
        if os.path.isdir(resource):
            for input_file in os.listdir(resource):
                parsed_dict.update(
                    _parse_yaml_path(os.path.join(resource, input_file)))
        elif input_files:
            for input_file in input_files:
                parsed_dict.update(_parse_yaml_path(input_file))
        else:
            parsed_dict.update(_parse_yaml_path(resource))
    return parsed_dict


def _parse_yaml_path(resource):

    try:
        # if resource is a path - parse as a yaml file
        if os.path.isfile(resource):
            with open(resource) as f:
                content = yaml.load(f.read())
        else:
            # parse resource content as yaml
            content = yaml.load(resource)
    except yaml.error.YAMLError as e:
        raise AriaCliError("'{0}' is not a valid YAML. {1}".format(
            resource, str(e)))

    # Emtpy files return None
    content = content or dict()
    if not isinstance(content, dict):
        raise AriaCliError()

    return content


def _plain_string_to_dict(input_string):
    input_string = input_string.strip()
    input_dict = {}
    mapped_inputs = input_string.split(';')
    for mapped_input in mapped_inputs:
        mapped_input = mapped_input.strip()
        if not mapped_input:
            continue
        split_mapping = mapped_input.split('=')
        try:
            key = split_mapping[0].strip()
            value = split_mapping[1].strip()
        except IndexError:
            raise AriaCliError(
                "Invalid input format: {0}, the expected format is: "
                "key1=value1;key2=value2".format(input_string))
        input_dict[key] = value
    return input_dict