Use template mechanism of nginx image
diff --git a/nginx/Dockerfile.entrypoint b/nginx/Dockerfile.entrypoint
index 34e10f1..2af13cb 100644
--- a/nginx/Dockerfile.entrypoint
+++ b/nginx/Dockerfile.entrypoint
@@ -14,11 +14,7 @@
         cp /etc/ssl/certs/sa-selfsigned.crt ${live}/${domain}/cert.pem
     fi
 
-    for f in /etc/nginx/conf.d/sa.conf; do
-        sed "s/miau.local/${domain}/" ${f}.template >${f}
-    done
+    chmod -R go-w /etc/nginx/certs/live/
 }
 
-chmod -R a-w /etc/nginx/certs/ /etc/nginx/conf.d/sa.conf
-
 exec /docker-entrypoint.sh "$@"