Set new feature for deployment

CHANGELOG.txt

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.3.0] - 2023-10-25
+### Added
+  - Add support for interpolating environment variables to tentaclio secrets file.
+
 ## [1.2.2] - 2023-10-18
 ### Added
   - Add support for connecting to SFTP via private key authentication. Replaces pysftp dependency with paramiko.

README.md

@@ -302,6 +302,14 @@ And make it accessible to tentaclio by setting the environmental variable `TENTA
 Alternatively you can run `curl https://raw.githubusercontent.com/octoenergy/tentaclio/master/extras/init_tentaclio.sh` to create a secrets file in `~/.tentaclio.yml` and
 automatically configure your environment.
 
+Environment variables can be included in the credentials file by using `${ENV_VARIABLE}` as it follows:
+```
+secrets:
+    db: postgresql://${DB_USER}:${DB_PASS}@myhost.com/database
+```
+Tentaclio will search `DB_USER` and `DB_PASS` in the environment and will interpolate their values with the secrets file content.
+
+
 ## Quick note on protocols structural subtyping.
 
 In order to abstract concrete dependencies from the implementation of data related functions (or in any part of the system really) we use typed [protocols](https://mypy.readthedocs.io/en/latest/protocols.html#simple-user-defined-protocols). This allows a more flexible dependency injection than using subclassing or [more complex approches](http://code.activestate.com/recipes/413268/). This idea is heavily inspired by how this exact thing is done in [go](https://www.youtube.com/watch?v=ifBUfIb7kdo). Learn more about this principle in our [tech blog](https://tech.octopus.energy/news/2019/03/21/python-interfaces-a-la-go.html).

setup.py

@@ -8,7 +8,7 @@
 from setuptools.command.install import install
 
 
-VERSION = "1.2.2"
+VERSION = "1.3.0"
 
 REPO_ROOT = pathlib.Path(__file__).parent
 

src/tentaclio/credentials/reader.py

@@ -14,7 +14,7 @@
 
 SECRETS = "secrets"
 TENTACLIO_SECRETS_FILE = "TENTACLIO__SECRETS_FILE"
-ENV_VARIABLE_PATTERN = r"\${[a-zA-Z_]+[a-zA-Z0-9_]*}"
+ENV_VARIABLE_PATTERN = re.compile(r"\${[a-zA-Z_]+[a-zA-Z0-9_]*}")
 NOT_VALID_ENV_VARIABLE_VALUES = "[${}]"
 
 
@@ -90,19 +90,19 @@ def _load_from_file(
         raise TentaclioFileError("File not found") from e
 
 
-def replace_env_variables(url: str) -> str:
+def _replace_env_variables(url: str) -> str:
     """Replace the environment variables inside the url by its value in the environment.
 
     Environment variables match the following format: ${ENV_VARIABLE_NAME}
     """
-    pattern = re.compile(ENV_VARIABLE_PATTERN)
-    env_variables = re.findall(pattern, url)
+    env_variables = re.findall(ENV_VARIABLE_PATTERN, url)
     for env_variable in env_variables:
         env_variable_name = re.sub(NOT_VALID_ENV_VARIABLE_VALUES, "", env_variable)
         env_value = os.getenv(env_variable_name)
         if not env_value:
             raise EnvironmentError(
-                f"Error while reading variable '{env_variable_name}' from the environment. "
+                f"Error while reading variable '{env_variable_name}' from the environment "
+                f"when interpolating it from the secrets file. "
                 f"Check that the variable exists in your environment."
             )
         url = url.replace(env_variable, env_value)
@@ -123,7 +123,7 @@ def add_credentials_from_reader(
     creds = _load_creds_from_yaml(yaml_reader)
     for name, url in creds.items():
         logger.info(f"Adding secret: {name}")
-        url = replace_env_variables(url)
+        url = _replace_env_variables(url)
         try:
             injector.register_credentials(urls.URL(url))
         except Exception as e: