Couldn't mount volume, what did I do wrong ?

Hi guys, totally new here. I’m trying to create a blog-like API using Phoenix. But the thing is when I try to mount a volume to store the file uploads, I couldn’t do it although I have followed the tutorial in the docs.

Here are the steps that I have done:

  • Creating the app
  • Create the postgres and attach it to the app
  • Deploy the app, it works with the db
  • Create the volume
  • Add the mounts section in fly.toml, try to deploy again
  • App running the release script, it says setting up volume ‘volume_name’
  • Error: release command failed, deployment aborted

And of course, it only fails when I add the volume. I remove the mounts section then it works just fine.

For the context, I’ll paste the Dockerfile and the fly.toml here. Hope someone can help. Thanks.


### Fist Stage - Building the Release


FROM hexpm/elixir:1.12.1-erlang-24.0.1-alpine-3.13.3 AS build

# install build dependencies

RUN apk add --no-cache build-base

# prepare build dir


# extend hex timeout


# install hex + rebar

RUN mix local.hex --force && \

mix local.rebar --force

# set build ENV as prod



# Copy over the mix.exs and mix.lock files to load the dependencies. If those

# files don't change, then we don't keep re-fetching and rebuilding the deps.

COPY mix.exs mix.lock ./

COPY config config

RUN mix deps.get --only prod && \

mix deps.compile

# install npm dependencies

# COPY assets/package.json assets/package-lock.json ./assets/

# RUN npm --prefix ./assets ci --progress=false --no-audit --loglevel=error

COPY priv priv

COPY assets assets

# NOTE: If using TailwindCSS, it uses a special "purge" step and that requires

# the code in `lib` to see what is being used. Uncomment that here before

# running the npm deploy script if that's the case.

# COPY lib lib

# build assets

# RUN npm run --prefix ./assets deploy

RUN mix phx.digest

# copy source here if not using TailwindCSS

COPY lib lib

# compile and build release

COPY rel rel

RUN mix do compile, release


### Second Stage - Setup the Runtime Environment


# prepare release docker image

FROM alpine:3.13.3 AS app

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


RUN chown nobody:nobody /app

USER nobody:nobody

COPY --from=build --chown=nobody:nobody /app/_build/prod/rel/behalf_be_phoenix ./

RUN mkdir -p /app/photos/





CMD ["bin/behalf_be_phoenix", "start"]
# fly.toml file generated for behalf-be-phoenix on 2021-10-21T15:51:33+07:00

app = "behalf-be-phoenix"

kill_signal = "SIGTERM"
kill_timeout = 5


  release_command = "/app/bin/behalf_be_phoenix eval BehalfBePhoenix.Release.migrate"


  allowed_public_ports = []
  auto_rollback = true

  http_checks = []
  internal_port = 4000
  protocol = "tcp"
  script_checks = []

    hard_limit = 25
    soft_limit = 20
    type = "connections"

    handlers = ["http"]
    port = 80

    handlers = ["tls", "http"]
    port = 443

    grace_period = "30s"
    interval = "15s"
    restart_limit = 6
    timeout = "2s"