Feature/environment var creds (#116)

- Change templates to interpolate environment variables in docker compose
- Change templates to invoke secrets for environment variable credentials in K8s configuration
- Update LLMs to pull in credentials from environment variables if not specified

trustgraph-vertexai/trustgraph/model/text_completion/vertexai/llm.py

@@ -7,6 +7,7 @@ Google Cloud.   Input is prompt, output is response.
 import vertexai
 import time
 from prometheus_client import Histogram
+import os
 
 from google.oauth2 import service_account
 import google
@@ -38,6 +39,7 @@ default_model = 'gemini-1.0-pro-001'
 default_region = 'us-central1'
 default_temperature = 0.0
 default_max_output = 8192
+default_private_key = os.getenv("VERTEXAI_KEY")
 
 class Processor(ConsumerProducer):
 
@@ -48,10 +50,13 @@ class Processor(ConsumerProducer):
         subscriber = params.get("subscriber", default_subscriber)
         region = params.get("region", default_region)
         model = params.get("model", default_model)
-        private_key = params.get("private_key")
+        private_key = params.get("private_key", default_private_key)
         temperature = params.get("temperature", default_temperature)
         max_output = params.get("max_output", default_max_output)
 
+        if private_key is None:
+            raise RuntimeError("Private key file not specified")
+
         super(Processor, self).__init__(
             **params | {
                 "input_queue": input_queue,