Container not running error for docker exec command

This is how my Dockerfile looks like

FROM elixir:1.10.4-alpine AS build

ARG CIRCLE_BUILD_NUM
ENV CIRCLE_BUILD_NUM=$CIRCLE_BUILD_NUM

ENV MIX_ENV=prod \
  LANG=C.UTF-8

RUN mix local.hex --force && \
    mix local.rebar --force

# Create the application build directory
RUN mkdir /apps
COPY . /apps
WORKDIR /apps/

COPY mix.exs mix.lock ./
COPY config config
RUN mix deps.get
RUN mix deps.compile

#releases
RUN MIX_ENV=prod mix release my_app

FROM alpine:3.12 as apps
WORKDIR /apps

RUN apk add --no-cache libressl ncurses-libs

RUN mkdir -p /apps/my_app

# create a new user
RUN addgroup -S elixir_app && adduser -S elixir_app -G elixir_app
RUN chown elixir_app:elixir_app /apps
USER elixir_app

COPY --from=build --chown=elixir_app:elixir_app /apps/_build/prod/rel/my_app /apps/my_app

And this is my docker-compose file

version: '3.2'

networks:
  net:

services:
  my_app:
   container_name: my_app
    image: "my_app/myapp-${CIRCLE_BUILD_NUM}"
    environment:
     ----------------------
    expose:
      - "${PORT}"
    ports:
      - "${PORT}:${PORT}"
    command: /apps/my_app/bin/my_app start

When I run docker-compose -f docker-compose.yml up -dI get

Starting my_app_1 … done

But When I run

docker exec -it my_app  /apps/my_app/bin/my_app eval "MyApp.Release.migrate"

getting

Error response from daemon: Container e91f88998632481a657d5c66eafaf4f970a4e3203aac129c46d194f31bcdab63 is not running

Can anyone help me with this?

Your container is missing an ENTRYPOINT.

Try starting the compose without -d to not have it vanish in the background, read the error messages that the container prints before dying.

Elixir 1.10 is based on alpine 3.13, you probably need to adjust your alpine version in the apps stage.