Implementation of PyYAML Reader with env var parsing.
Inspired by envyaml: https://github.com/thesimj/envyaml
The Reader is the very first step of the PyYAML parsing process and this is where the environment variable is being parsed.
The environment variable parsing can be anywhere in the yaml file, the parsing is done in the very early stages of the PyYAML loading process. It is possible to inject a YAML structure using it
The code below is an example of what I mean be anywere:
import os
from yaml_env_var_parser import load
# env vars are replaced on keys
os.environ['MY_KEY'] = 'key'
# they might also be YAML tags
os.environ['TIMESTAMP_TAG'] = '!!timestamp'
# this will inject `another_key` into the yaml data
os.environ['MY_COMPLEX_DATA'] = """"simple_data"
another_key: "its possible to create new keys with env vars. we might call it YAML INJECTION"
"""
yaml_data_str = """
${MY_KEY}: "data"
complex_data: ${MY_COMPLEX_DATA}
timestamp_tag: ${TIMESTAMP_TAG} 2022-01-01 00:00:00
"""
parsed = load(yaml_data_str)
print(parsed)
Output:
{'key': 'data', 'complex_data': 'simple_data', 'another_key': 'its possible to create new keys with env vars. we might call it YAML INJECTION', 'timestamp_tag': datetime.datetime(2022, 1, 1, 0, 0)}
The key another_key does not exist in yaml_data_str yaml str definition but it is added from the environment variable ${MY_COMPLEX_DATA}