starting redis integration for get configuration

api/api.py

@@ -7,10 +7,11 @@
 import logging
 import sys
 
+from globals import env
 from internal import logger_init, check_env_vars, set_log_level
 from routers.configuration.operations import router as configuration_router
 
-# check if python version is what this is written with:
+# python version sanity check
 
 if sys.version_info < (3, 10):
     print('ERROR: Python 3.10+ required.')
@@ -31,7 +32,8 @@
     logger_init()
 
 # check env and use defaults if not present
-env = check_env_vars()
+# this populates env dict global
+check_env_vars()
 
 # set logger level based on what we got back
 set_log_level(env['LOG_LEVEL'])

api/internal/__init__.py

@@ -3,4 +3,5 @@
 from .logger_init import logger_init
 from .check_env_vars import check_env_vars
 from .set_log_level import set_log_level
+from .check_conf_server import check_conf_server
 

api/internal/check_conf_server.py

@@ -0,0 +1,37 @@
+
+from typing import Tuple
+from xmlrpc.client import Boolean
+import redis
+from globals import env
+
+
+def check_conf_server(
+    host_param: str = None, 
+    port_param: str = None) -> Tuple:
+    """Check if the Redis configuration endpoint is alive. 
+    If host and/or port aren't provided, pull values from REDIS_HOST and REDIS_port
+    environment variables
+    
+    Arguments:
+    host_param (Optional): the Redis endpoint (.e.g, 'redis://localhost' or '127.0.0.1')
+    port_param (Optional): the Redis port
+    
+    Return:
+    (status_code, r) tuple where status_code is boolean for the check success, 
+    and r is the Redis handle if successful
+    """
+
+    if not host_param:
+        host_param = env['REDIS_HOST']
+    if not port_param:
+        port_param = env['REDIS_PORT']
+
+    try:
+        r = redis.StrictRedis(host=host_param, port=port_param, decode_responses=True )
+        if r.ping():
+            return True, r
+        return False, None
+
+    except redis.ConnectionError:
+        return False, None
+

api/internal/check_env_vars.py

@@ -1,18 +1,18 @@
-from ast import Dict
 import os
 import logging
+from typing import Dict
+from globals import env
 
-def check_env_vars() -> Dict:
-    """
-    Checks if environment variables we care about are present.
+def check_env_vars():
+    """Checks if environment variables we care about are present.
     If so, accept them.
     If not, substitute a reasonable default.
-
-    Returns:
-        Dict: returns a dictionary of environment variables and their assigned
-        values. NOT typesafe. Consumer is resonsible for typecasting as needed.
+        
+    Sets globals.env Dict of environment variables and their assigned
+    values.
+    
+    NOT typesafe. Consumer is resonsible for typecasting as needed.
     """
-
     # access the 'global' logger
     logger = logging.getLogger('api')
 
@@ -36,8 +36,6 @@ def check_env_vars() -> Dict:
 
     all_env_vars = dict(os.environ)
 
-    env = {}
-
     logger.debug(f'all_env_vars: {all_env_vars}')
     logger.debug(f'env = {env}')
 
@@ -50,5 +48,3 @@ def check_env_vars() -> Dict:
             logger.debug(f'env: {var}={env[var]} (default)')
 
     logger.debug(f'env = {env}')
-
-    return env

api/routers/configuration/delete.py

@@ -1,8 +1,10 @@
 # Configuration DELETE
 
 from ast import Dict
+from fastapi import Response, status
 
 def delete(
+        response: Response,
         instance_param: str = None,
         section_param: str = None
 ) -> Dict:

api/routers/configuration/get.py

@@ -1,14 +1,42 @@
 # Configuration GET
 
+from fastapi import Response, status
+from globals import env
 from ast import Dict
+from internal.check_conf_server import check_conf_server
 
 def get(
+        response: Response,
         instance_param: str = None,
         section_param: str = None
 ) -> Dict:
+    """Implement GET method for 
+        /v1/configuration
 
+        /v1/configuration/{instance}
+        
+        /v1/configuration/{instance}/{section}
+
+    Args:
+        response (Response): pass through for setting specific status
+        instance_param (str, optional): Name of the instance. Defaults to None.
+        section_param (str, optional): Name of the configuration section. Defaults to None.
+
+    Returns:
+        Dict: response from the operation
+
+    HTTP Status Codes:
+        424: Redis failure
+    """
     return_dict = {'instance': instance_param, 'section': section_param}
 
-# redis code goes here
+    # do we have a working Redis connection?
+    redis_status, r = check_conf_server()
+    if not redis_status:
+        response.status_code = status.HTTP_424_FAILED_DEPENDENCY
+        return { 'message': 'redis connection failed' }
+    # we have a working redis connection
+
+    # do something useful with redis
 
     return return_dict

api/routers/configuration/operations.py

@@ -1,7 +1,7 @@
 # Configuration operations
 
 from enum import Enum
-from fastapi import APIRouter, Body
+from fastapi import APIRouter, Body, Response
 
 from .get import get as configuration_get
 from .put import put as configuration_put
@@ -27,10 +27,22 @@ class SectionName(str, Enum):
 @router.get('/configuration/{instance}')
 @router.get('/configuration/{instance}/{section}')
 async def get_config(
+    response: Response,
     instance: str = None,
     section: SectionName = None
 ):
+    """Handler for GET operation on configuration
+
+    Args:
+        response (Response): HTTP status code pass-through
+        instance (str, optional): Name of the instance. Defaults to None.
+        section (SectionName, optional): Name of the configuration section. Defaults to None.
+
+    Returns:
+        Dict: HTTP operation response
+    """
     return configuration_get(
+        response=response,
         instance_param=instance,
         section_param=section
     )
@@ -43,12 +55,14 @@ async def get_config(
 @router.put('/configuration/{instance}')
 @router.put('/configuration/{instance}/{section}')
 async def put_config(
+    response: Response,
     instance: str = None,
     section: SectionName = None,
     body: dict = Body (...)
 ):
 
     return configuration_put(
+        response=response,
         instance_param=instance,
         section_param=section
     )

api/routers/configuration/patch.py

@@ -1,8 +1,10 @@
 # Configuration PATCH
 
 from ast import Dict
+from fastapi import Response, status
 
 def patch(
+        response: Response,
         instance_param: str = None,
         section_param: str = None        
 ) -> Dict:

api/routers/configuration/put.py

@@ -1,8 +1,10 @@
 # Configuration PUT
 
 from ast import Dict
+from fastapi import Response, status
 
 def put(
+        response: Response,
         instance_param: str = None,
         section_param: str = None        
 ) -> Dict: