"""Shared environment variable resolution utilities.
Provides robust, thin environment variable resolution that can be used by both Docker
orchestration and pytest fixtures.
"""
import os
from pathlib import Path
def resolve_env_template(
template_file: Path,
strict: bool = False,
critical_prefixes: tuple[str, ...] = ("AIDB_",),
) -> dict[str, str]:
"""Resolve environment variables from a template file.
Supports shell variable substitution syntax like ${VAR} and direct values.
Parameters
----------
template_file : Path
Path to .env.test or similar template file
strict : bool
If True, only include variables that fully resolve (no unresolved ${VAR})
If False, include all variables, setting unresolved ones to empty string
critical_prefixes : tuple[str, ...]
Variable prefixes that should always be included even if unresolved
Returns
-------
Dict[str, str]
Resolved environment variables
Examples
--------
Template file content:
API_KEY=${API_KEY}
DATABASE_URL=sqlite:///test.db
MISSING_VAR=${UNDEFINED_VAR}
With strict=False:
{'API_KEY': 'secret_...', 'DATABASE_URL': 'sqlite:///test.db',
'MISSING_VAR': ''}
With strict=True:
{'API_KEY': 'secret_...', 'DATABASE_URL': 'sqlite:///test.db'}
"""
resolved_vars: dict[str, str] = {}
if not template_file.exists():
return resolved_vars
with template_file.open() as f:
for line in f:
line = line.strip()
if not line or line.startswith("#") or "=" not in line:
continue
key, value = line.split("=", 1)
key = key.strip()
value = value.strip()
# Use os.path.expandvars for robust variable substitution
resolved_value = os.path.expandvars(value)
# Check if there are still unresolved variables
has_unresolved_vars = "${" in resolved_value and "}" in resolved_value
# Handle unresolved variables
if has_unresolved_vars:
# Check if this is a critical variable that should always be included
is_critical = any(
key.startswith(prefix) for prefix in critical_prefixes
)
if strict and not is_critical:
# In strict mode, skip unresolved non-critical variables
continue
# Include critical variables or in non-strict mode, set to empty
resolved_vars[key] = ""
else:
# Successfully resolved or static value
resolved_vars[key] = resolved_value
return resolved_vars
def apply_env_template_to_environ(template_file: Path, strict: bool = False) -> int:
"""Resolve and apply environment template to os.environ.
This is a convenience function that applies resolved variables directly
to the current process environment.
Parameters
----------
template_file : Path
Path to .env.test or similar template file
strict : bool
If True, only apply variables that fully resolve
Returns
-------
int
Number of variables that were applied to os.environ
"""
resolved = resolve_env_template(template_file, strict=strict)
for key, value in resolved.items():
os.environ[key] = value
return len(resolved)
