diff --git a/docker-compose.yml b/docker-compose.yml
index 36f75cf..e4612fe 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,53 +1,55 @@
 # Version of docker-compose.
-version: '3'
+version: "3"
 
 # Containers we're going to run.
 services:
-   # Our Phoenix container.
-   phoenix:
-      # The build parameters for this container.
-      build:
-          # Here we define that it should build from the current directory.
-          context: .
-          args:
-            - MIX_ENV=prod
-      environment:
-         # Variables to connect to our Postgres server.
-         DB_USER: postgres
-         DB_PASSWORD: postgres
-         DB_NAME: arke-test
-         DB_HOSTNAME: db
-         DB_PORT: 5432
+  # Our Phoenix container.
+  phoenix:
+    # The build parameters for this container.
+    build:
+      # Here we define that it should build from the current directory.
+      context: .
+      args:
+        - MIX_ENV=prod
+    environment:
+      # Variables to connect to our Postgres server.
+      DB_USER: postgres
+      DB_PASSWORD: postgres
+      DB_NAME: arke-test
+      DB_HOSTNAME: db
+      DB_PORT: 5432
 
-         PGUSER: postgres
-         PGPASSWORD: postgres
-         PGDATABASE: arke-test
-         PGPORT: 5432
-         PGHOST: db
+      PGUSER: postgres
+      PGPASSWORD: postgres
+      PGDATABASE: arke-test
+      PGPORT: 5432
+      PGHOST: db
 
-         MIX_ENV: prod
-         SECRET_KEY_BASE: change_me
-      ports:
-         # Mapping the port to make the Phoenix app accessible outside of the container.
-         - '4000:4000'
-      depends_on:
-         # The DB container needs to be started before we start this container.
-         - db
-   db:
-      # We use the predefined Postgres image.
-      image: postgres:14.4
-      environment:
-         # Set user/password for Postgres.
-         POSTGRES_USER: postgres
-         POSTGRES_PASSWORD: postgres
-         # Set a path where Postgres should store the data.
-         PGDATA: /var/lib/postgresql/data/pgdata
-      restart: always
-      ports:
-         # Mapping the port to make the Phoenix app accessible outside of the container.
-        - '5432:5432'
-      volumes:
-         - pgdata:/var/lib/postgresql/data
+      PROJECT_ID: ${PROJECT_ID}
+
+      MIX_ENV: prod
+      SECRET_KEY_BASE: change_me
+    ports:
+      # Mapping the port to make the Phoenix app accessible outside of the container.
+      - "4000:4000"
+    depends_on:
+      # The DB container needs to be started before we start this container.
+      - db
+  db:
+    # We use the predefined Postgres image.
+    image: postgres:14.4
+    environment:
+      # Set user/password for Postgres.
+      POSTGRES_USER: postgres
+      POSTGRES_PASSWORD: postgres
+      # Set a path where Postgres should store the data.
+      PGDATA: /var/lib/postgresql/data/pgdata
+    restart: always
+    ports:
+      # Mapping the port to make the Phoenix app accessible outside of the container.
+      - "5432:5432"
+    volumes:
+      - pgdata:/var/lib/postgresql/data
 # Define the volumes.
 volumes:
-   pgdata:
\ No newline at end of file
+  pgdata: