Using compose's develop

Dockerfile

@@ -1,15 +1,15 @@
 FROM elixir:1.19.5-otp-27 AS base
 
 WORKDIR /app
+COPY mix.* /app
 RUN apt-get update && apt-get install -y cmake
 
 FROM base AS dev
 COPY docker-entrypoint.sh /app
-VOLUME /app/mix.exs /app/mix.lock /app/_build /app/deps /app/config /app/lib /app/test
+VOLUME /app/_build /app/deps /app/config /app/lib /app/test
 ENV SNAME="srv" COOKIE="cookie"
 
 CMD ["/bin/sh", "/app/docker-entrypoint.sh"]
 
 FROM base AS builder
-COPY mix.* /app
 RUN mix do deps.get + deps.compile

compose.yml

@@ -3,9 +3,14 @@ services:
     build:
       context: .
       target: dev
+    develop:
+      watch:
+        - path: ./
+          include: "mix.*"
+          target: "/app"
+          action: sync+restart
+          initial_sync: true
     volumes:
-      - "./mix.exs:/app/mix.exs"
-      - "./mix.lock:/app/mix.lock"
       - "app_build:/app/_build"
       - "app_deps:/app_deps"
       - "./config:/app/config"