Add expansion feature

Read dotenv file and expand based on env and system env

pystarport/cluster.py

@@ -18,12 +18,14 @@
 import tomlkit
 import yaml
 from dateutil.parser import isoparse
+from dotenv import dotenv_values, load_dotenv
 from supervisor import xmlrpc
 from supervisor.compat import xmlrpclib
 
 from . import ports
 from .app import CHAIN, IMAGE, SUPERVISOR_CONFIG_FILE
 from .cosmoscli import ChainCommand, CosmosCLI, ModuleAccount, module_address
+from .expansion import expand_posix_vars
 from .ledger import ZEMU_BUTTON_PORT, ZEMU_HOST
 from .utils import format_doc_string, interact, write_ini
 
@@ -906,6 +908,20 @@ def init_cluster(
 ):
     config = yaml.safe_load(open(config_path))
 
+    if "dotenv" in config:
+        dotenv = config.pop("dotenv", {})
+        if not isinstance(dotenv, str):
+            raise ValueError(f"Invalid value passed to dotenv: {dotenv}")
+        config_vars = load_system_envvars()
+        env_path = Path(config_path).parent.joinpath(dotenv)
+        if not env_path.is_file():
+            raise ValueError(
+                f"Dotenv specified in config but not found at path: {env_path}"
+            )
+        config_vars.update(dotenv_values(dotenv_path=env_path))  # type: ignore
+        load_dotenv(dotenv_path=env_path)
+        config = expand_posix_vars(config, config_vars)
+
     relayer_config = config.pop("relayer", {})
     for chain_id, cfg in config.items():
         cfg["path"] = str(config_path)
@@ -1101,3 +1117,8 @@ def format_value(v, ctx):
     supervisord.wait()
     t.stop()
     t.join()
+
+
+def load_system_envvars():
+    config_vars = dict(os.environ)
+    return config_vars

pystarport/expansion.py

@@ -0,0 +1,58 @@
+import re
+from typing import Any, Mapping, Optional, Text
+
+from dotenv.variables import parse_variables
+
+
+def expand_posix_vars(obj: Any, variables: Mapping[Text, Optional[Any]]) -> Any:
+    """expand_posix_vars recursively expands POSIX values in an object.
+
+    Args:
+        obj (any): object in which to interpolate variables.
+        variables (dict): dictionary that maps variable names to their value
+    """
+    if isinstance(obj, (dict,)):
+        for key, val in obj.items():
+            obj[key] = expand_posix_vars(val, variables)
+    elif isinstance(obj, (list,)):
+        for index in range(len(obj)):
+            obj[index] = expand_posix_vars(obj[index], variables)
+    elif isinstance(obj, (str,)):
+        obj = _str_to_python_value(_expand(obj, variables))
+    return obj
+
+
+def _expand(value, variables={}):
+    """_expand does POSIX-style variable expansion
+
+    This is adapted from python-dotenv, specifically here:
+
+    https://github.com/theskumar/python-dotenv/commit/17dba65244c1d4d10f591fe37c924bd2c6fd1cfc
+
+    We need this layer here so we can explicitly pass in variables;
+    python-dotenv assumes you want to use os.environ.
+    """
+
+    if not isinstance(value, (str,)):
+        return value
+    atoms = parse_variables(value)
+    return "".join([str(atom.resolve(variables)) for atom in atoms])
+
+
+INT_REGEX = re.compile(r"^[-+]?[0-9]+$")
+
+
+def _str_to_python_value(val):
+    """_str_to_python_value infers the data type from a string.
+
+    This could eventually use PyYAML's parsing logic.
+    """
+    if not isinstance(val, (str,)):
+        return val
+    elif val == "true" or val == "True" or val == "on":
+        return True
+    elif val == "false" or val == "False" or val == "off":
+        return False
+    # elif INT_REGEX.match(val):
+    #     return int(val)
+    return val