use compose environment for devcontainer

- add redis container

api/.devcontainer/devcontainer.json

@@ -2,21 +2,9 @@
 // README at: https://github.com/devcontainers/templates/tree/main/src/python
 {
 	"name": "Advent22 API",
-	"build": {
+	"dockerComposeFile": "docker-compose.yml",
-		"dockerfile": "Dockerfile",
+	"service": "api",
-		"context": "..",
+	"workspaceFolder": "/workspaces/${localWorkspaceFolderBasename}",
-		"args": {
-			// Update 'VARIANT' to pick a Python version.
-			// Append -bullseye or -buster to pin to an OS version.
-			// Use -bullseye variants on local on arm64/Apple Silicon.
-			"VARIANT": "3.11-bookworm",
-			// Options
-			"NODE_VERSION": "none"
-		}
-	},
-	"containerEnv": {
-		"TZ": "Europe/Berlin"
-	},
 	// Configure tool-specific properties.
 	"customizations": {
 		// Configure properties specific to VS Code.

api/.devcontainer/docker-compose.yml

@@ -0,0 +1,32 @@
+version: "3.8"
+
+services:
+  api:
+    build:
+      context: "."
+      dockerfile: "Dockerfile"
+      args:
+        # Update 'VARIANT' to pick a Python version.
+        # Append -bookworm, -bullseye or -buster to pin to an OS version.
+        # Use -bookworm or -bullseye variants on local on arm64/Apple Silicon.
+        VARIANT: "3.11-bookworm"
+        NODE_VERSION: "none"
+
+    environment:
+      TZ: "Europe/Berlin"
+
+    volumes:
+      - "../..:/workspaces:cached"
+    
+    # Overrides default command so things don't shut down after the process ends.
+    command: "sleep infinity"
+
+    # Runs app on the same network as the redis container, allows "forwardPorts" in devcontainer.json function.
+    network_mode: "service:redis"
+
+    # Use "forwardPorts" in **devcontainer.json** to forward an app port locally. 
+    # (Adding the "ports" property to this file will not forward from a Codespace.)
+
+  redis:
+    image: "redis:7"
+    restart: "unless-stopped"