Add function for Flask app to read config from a directory.

The application now checks for an environment variable,
OVERRIDE_CONFIG_DIRECTORY. If that value is set, it loops all the files
in the specified directory and checks if their names correspond to known
configuration settings. The contents of any matching files are read and
set as the new configuration value for that setting. This will allow us
to read mounted Azure Key Vault items as config values.

This also moves the functionality for applying environment variables to
the config into an analogous function.
This commit is contained in:
dandds 2019-12-05 14:11:35 -05:00
parent 972cf14a66
commit f8c31e4dcf
2 changed files with 81 additions and 8 deletions

View File

@ -200,23 +200,21 @@ def make_config(direct_config=None):
ENV_CONFIG_FILENAME = os.path.join(
os.path.dirname(__file__), "../config/", "{}.ini".format(ENV.lower())
)
OVERRIDE_CONFIG_FILENAME = os.getenv("OVERRIDE_CONFIG_FULLPATH")
OVERRIDE_CONFIG_DIRECTORY = os.getenv("OVERRIDE_CONFIG_DIRECTORY")
config = ConfigParser(allow_no_value=True)
config.optionxform = str
config_files = [BASE_CONFIG_FILENAME, ENV_CONFIG_FILENAME]
if OVERRIDE_CONFIG_FILENAME:
config_files.append(OVERRIDE_CONFIG_FILENAME)
# ENV_CONFIG will override values in BASE_CONFIG.
config.read(config_files)
if OVERRIDE_CONFIG_DIRECTORY:
apply_config_from_directory(OVERRIDE_CONFIG_DIRECTORY, config)
# Check for ENV variables as a final source of overrides
for confsetting in config.options("default"):
env_override = os.getenv(confsetting.upper())
if env_override:
config.set("default", confsetting, env_override)
apply_config_from_environment(config)
# override if a dictionary of options has been given
if direct_config:
@ -244,6 +242,36 @@ def make_config(direct_config=None):
return map_config(config)
def apply_config_from_directory(config_dir, config, section="default"):
"""
Loop files in a directory, check if the names correspond to
known config values, and apply the file contents as the value
for that setting if they do.
"""
for confsetting in os.listdir(config_dir):
if confsetting in config.options(section):
full_path = os.path.join(config_dir, confsetting)
with open(full_path, "r") as conf_file:
config.set(section, confsetting, conf_file.read().strip())
return config
def apply_config_from_environment(config, section="default"):
"""
Loops all the configuration settins in a given section of a
config object and checks whether those settings also exist as
environment variables. If so, it applies the environment
variables value as the new configuration setting value.
"""
for confsetting in config.options(section):
env_override = os.getenv(confsetting.upper())
if env_override:
config.set(section, confsetting, env_override)
return config
def make_redis(app, config):
r = redis.Redis.from_url(config["REDIS_URI"])
app.redis = r

View File

@ -1,8 +1,13 @@
import os
from configparser import ConfigParser
import pytest
from atst.app import make_crl_validator
from atst.app import (
make_crl_validator,
apply_config_from_directory,
apply_config_from_environment,
)
@pytest.fixture
@ -22,3 +27,43 @@ def test_make_crl_validator_creates_crl_dir(app, tmpdir, replace_crl_dir_config)
replace_crl_dir_config(crl_dir)
make_crl_validator(app)
assert os.path.isdir(crl_dir)
@pytest.fixture
def config_object():
config = ConfigParser()
config.optionxform = str
config.read_string("[default]\nFOO=BALONEY")
return config
def test_apply_config_from_directory(tmpdir, config_object):
config_setting = tmpdir.join("FOO")
with open(config_setting, "w") as conf_file:
conf_file.write("MAYO")
apply_config_from_directory(tmpdir, config_object)
assert config_object.get("default", "FOO") == "MAYO"
def test_apply_config_from_directory_skips_unknown_settings(tmpdir, config_object):
config_setting = tmpdir.join("FLARF")
with open(config_setting, "w") as conf_file:
conf_file.write("MAYO")
apply_config_from_directory(tmpdir, config_object)
assert "FLARF" not in config_object.options("default")
def test_apply_config_from_environment(monkeypatch, config_object):
monkeypatch.setenv("FOO", "MAYO")
apply_config_from_environment(config_object)
assert config_object.get("default", "FOO") == "MAYO"
def test_apply_config_from_environment_skips_unknown_settings(
monkeypatch, config_object
):
monkeypatch.setenv("FLARF", "MAYO")
apply_config_from_environment(config_object)
assert "FLARF" not in config_object.options("default")