I build a Dockerfile as:

FROM hexpm/elixir:1.15.7-erlang-26.1.2-alpine-3.17.5 AS releaser

RUN apk add --no-cache build-base git python3 curl

WORKDIR /app

RUN mix do local.hex --force, local.rebar --force

COPY config/ ./config/
COPY mix.exs mix.lock ./

COPY apps/liquid_auth/mix.exs ./apps/liquid_auth/
COPY apps/liquid_accounts/mix.exs ./apps/liquid_accounts/
COPY apps/liquid_operations/mix.exs ./apps/liquid_operations/
COPY apps/proxy_web/mix.exs ./apps/proxy_web/
COPY apps/release/mix.exs ./apps/release/

COPY apps/liquid_auth/priv ./apps/liquid_auth/
COPY apps/liquid_accounts/priv ./apps/liquid_accounts/
COPY apps/liquid_operations/priv ./apps/liquid_operations/

ENV MIX_ENV=prod

RUN mix deps.get
RUN mix deps.compile

COPY apps/liquid_auth/lib/ ./apps/liquid_auth/
COPY apps/liquid_accounts/lib/ ./apps/liquid_accounts/
COPY apps/liquid_operations/lib/ ./apps/liquid_operations/
COPY apps/proxy_web/lib/ ./apps/proxy_web/
COPY apps/release/lib/ ./apps/release/

RUN mix compile --force
RUN mix release

FROM alpine:3.17.5 AS app

RUN apk add --no-cache libstdc++ openssl ncurses-libs

EXPOSE 4000

ENV PORT=4000 \
    MIX_ENV=prod \
    SHELL=/bin/bash \
    PHX_SERVER=true

WORKDIR /app

COPY --from=releaser /app/_build/prod/rel/liquid ./

CMD ["bin/liquid", "eval", "Release.migrate", "&&", "exec", "bin/liquid", "start"]

and this is my docker-compose.yml:

 version: "3.8"

services:
  pescarte:
    build:
      context: .
    container_name: liquid_dev
    ports:
      - 4000:4000
    depends_on:
      - database
    env_file:
      - .env-sample
    volumes:
      - .:/src
    environment:
      MIX_ENV: dev
    stdin_open: true
    tty: true

  database:
    image: postgres:14.6
    container_name: liquid_database
    environment:
      - POSTGRES_USER=liquid
      - POSTGRES_PASSWORD=liquid
    ports:
      - 5432:5432
    volumes:
      - .postgres:/var/lib/postgresql/data
    healthcheck:
      test: [ "CMD-SHELL", "pg_isready -U liquid -d liquid" ]
      interval: 5s
      timeout: 2s
      retries: 1

However when i try to run docker compose up I get this error:

 liquid_dev       | ** (UndefinedFunctionError) function Release.migrate/0 is undefined (module Release is not available)
liquid_dev       |     Release.migrate()
liquid_dev       |     nofile:1: (file)
liquid_dev       |     (stdlib 5.1.1) erl_eval.erl:750: :erl_eval.do_apply/7
liquid_dev       |     (elixir 1.15.7) lib/code.ex:543: Code.validated_eval_string/3
liquid_dev exited with code 1

The full repository with the source code (empty phoenix apps) can be found here

And trying to build with docker build -t liquid-pescarte —no-cache —progress plain . gives all correct instructions and it compiles down all my umbrella apps, so I didn’t understand why on the runtime its brokes.