milestone 14: build, package, sign and publish releases

deploy/docker/compose.yaml

@@ -1,9 +1,10 @@
 services:
   nxdns:
-    image: nxdns
-    build:
-      context: ../..
-      dockerfile: deploy/docker/Dockerfile
+    # Published multi-architecture image. Pin an exact version in production:
+    # NXDNS_VERSION=0.0.1 docker compose up -d. To run a locally built image
+    # instead, build it first (see deploy/docker/Dockerfile) and set
+    # NXDNS_IMAGE=nxdns.
+    image: ${NXDNS_IMAGE:-git.mial.net/mokhtar/nxdns:${NXDNS_VERSION:-latest}}
     restart: unless-stopped
     # First boot needs ./etc-nxdns/config.zon with a `default` group and at
     # least one enabled upstream, or the container exits with code 2. The file