Build KarlDNS self-hosted DynDNS service

docker-compose.yml

@@ -1,13 +1,16 @@
 services:
-  ddns:
+  karldns:
     build: .
     restart: unless-stopped
     env_file:
       - .env
+    environment:
+      DDNS_DATABASE: ${DDNS_DATABASE:-/data/ddns.sqlite3}
     ports:
       - "8080:8080"
     volumes:
-      - ddns-data:/data
+      - karldns-data:/data
+    # Keep the default single-worker command unless multi-worker rate limiting has been tested.
     healthcheck:
       test: ["CMD", "python", "-c", "import os, urllib.parse, urllib.request; host=urllib.parse.urlparse(os.environ['DDNS_PUBLIC_BASE_URL']).hostname; req=urllib.request.Request('http://127.0.0.1:8080/healthz', headers={'Host': host}); urllib.request.urlopen(req, timeout=2).read()"]
       interval: 30s
@@ -15,4 +18,4 @@ services:
       retries: 3
 
 volumes:
-  ddns-data:
+  karldns-data: