Support grafana alloy credentials in an optional env file (#259)

Author: febus982

.dockerignore

@@ -314,3 +314,5 @@ cython_debug/
 .git
 .github
 .gitignore
+
+*.env

.gitignore

@@ -283,3 +283,4 @@ dmypy.json
 # Cython debug symbols
 cython_debug/
 
+credentials.env

docker-compose.yaml

@@ -42,6 +42,12 @@ services:
 
   otel-collector:
     image: grafana/alloy:latest
+    # You can add the Grafana Cloud credentials in this file
+    # and push observability directly to the provider.
+    # Refer to the config.alloy file to see what credentials we need.
+    env_file:
+      - path: ./credentials.env
+        required: false
     depends_on:
       - jaeger
     ports:
@@ -154,4 +160,3 @@ services:
     command:
       - "make"
       - "test"
-