AWS lambda extensions not sharing environment variables - amazon-web-services

Question

The following is a secrets-wrapper.py lambda extension:
#!/usr/bin/env python3
import boto3
import json
import os
LAMBDA_WRAPPER_NAME = "secrets-wrapper"
def debug_print(message):
print(message, flush=True)
def error_print(message):
print(message, flush=True)
def load_secrets():
if not 'APP_PARAMS_PATH' in os.environ:
error_print(
f"{LAMBDA_WRAPPER_NAME} unable to load secrets APP_PARAMS_PATH not found")
return
app_config_path = os.environ['APP_PARAMS_PATH']
if 'APP_ENV' in os.environ:
env = os.environ['APP_ENV']
full_config_path = '/' + env + '/' + app_config_path
else:
full_config_path = '/' + app_config_path
debug_print(
f"{LAMBDA_WRAPPER_NAME} Loading secrets for path {full_config_path}")
try:
client = boto3.client('ssm')
# Get all parameters for this app
param_details = client.get_parameters_by_path(
Path=full_config_path,
Recursive=False,
WithDecryption=True
)
# Loop through the returned parameters and populate the ConfigParser
if 'Parameters' in param_details:
for param in param_details.get('Parameters'):
debug_print(f"Found param: {param}")
param_name = param.get('Name').split("/")[-1]
debug_print(f"Name: {param_name}")
param_value = param.get('Value')
debug_print(f"Value: {param_value}")
os.environ[param_name] = param_value
except:
debug_print(f"{LAMBDA_WRAPPER_NAME} could not load from SSM")
raise Exception(f"{LAMBDA_WRAPPER_NAME} could not load from SSM")
def main():
load_secrets()
# Start the function
args = os.sys.argv[1:]
os.system(" ".join(args))
if __name__ == "__main__":
main()
and this is the function:
import json
import os
def lambda_handler(event, context):
# TODO implement
print(f"ENV foo check: {`os.environ.get('foo')`}", flush=True)
return {
'statusCode': 200,
'body': json.dumps('Hello from Lambda!')
}
when setting the APP_ENV to the lambda function:
aws lambda update-function-configuration --function-name my-function-example \
--environment "Variables={APP_NAME=myApp}"
within the lambda-extension it fetches no problem:
env = os.environ['APP_ENV'] #dev
However, when setting the environment variables within the extension os.environ[param_name] = param_value
when fetching it back in the invoked function os.environ.get('foo')
it is returned as None as if it was not set. If I output the set environment variable anywhere in the extension it will be indeed set.
Question is:
is the environment variable strictly one direction?
if not, how can I share ENV variables from extension to runtime function?