ERROR REPORT ... "Invalid -name given to erl,"

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1

Hi,

I’m attempting to troubleshoot an app locally that fails to start on Fly.io.

When running it in a Docker container, I get the following message:

“Invalid -name given to erl,”

Then the application exits.

Does someone know what can be the issue?

Many thanks in advance for any hint you may provide.

Francis Renaud

2

You’ve posted the error message:

Here’s the documentation for the -name option to erl.

Beyond that, you’re going to need to give folks more information to understand what’s going wrong.

  • what specific value is being passed there?
  • where did that value come from? Are you missing environment variables, etc?

Posting your Dockerfile can help answer some of those questions.

2 Likes
3

Thank you for taking the time to answer and for the pointer to the documentation.

The Dockerfile below is the one that was generated when I ran fly launch to deploy a simple LiveView app to Fly.io.

For some reason a wrong (empty) node name is passed to the erl command under the hood.

Does someone know where this node name is supposed to come from?

Here’s the Dockerfile

# instead of Alpine to avoid DNS resolution issues in production.
#
# https://hub.docker.com/r/hexpm/elixir/tags?page=1&name=ubuntu
# https://hub.docker.com/_/ubuntu?tab=tags
#
# This file is based on these images:
#
#   - https://hub.docker.com/r/hexpm/elixir/tags - for the build image
#   - https://hub.docker.com/_/debian?tab=tags&page=1&name=bullseye-20240423-slim - for the release image
#   - https://pkgs.org/ - resource for finding needed packages
#   - Ex: hexpm/elixir:1.16.2-erlang-26.2.5-debian-bullseye-20240423-slim
#
ARG ELIXIR_VERSION=1.16.2
ARG OTP_VERSION=26.2.5
ARG DEBIAN_VERSION=bullseye-20240423-slim

ARG BUILDER_IMAGE="hexpm/elixir:${ELIXIR_VERSION}-erlang-${OTP_VERSION}-debian-${DEBIAN_VERSION}"
ARG RUNNER_IMAGE="debian:${DEBIAN_VERSION}"

FROM ${BUILDER_IMAGE} as builder

# install build dependencies
RUN apt-get update -y && apt-get install -y build-essential git \
    && apt-get clean && rm -f /var/lib/apt/lists/*_*

# prepare build dir
WORKDIR /app

# install hex + rebar
RUN mix local.hex --force && \
    mix local.rebar --force

# set build ENV
ENV MIX_ENV="prod"

# install mix dependencies
COPY mix.exs mix.lock ./
RUN mix deps.get --only $MIX_ENV
RUN mkdir config

# copy compile-time config files before we compile dependencies
# to ensure any relevant config change will trigger the dependencies
# to be re-compiled.
COPY config/config.exs config/${MIX_ENV}.exs config/
RUN mix deps.compile

COPY priv priv

COPY lib lib

COPY assets assets

# compile assets
RUN mix assets.deploy

# Compile the release
RUN mix compile

# Changes to config/runtime.exs don't require recompiling the code
COPY config/runtime.exs config/

COPY rel rel
RUN mix release

# start a new build stage so that the final image will only contain
# the compiled release and other runtime necessities
FROM ${RUNNER_IMAGE}

RUN apt-get update -y && apt-get install -y libstdc++6 openssl libncurses5 locales \
  && apt-get clean && rm -f /var/lib/apt/lists/*_*

# Set the locale
RUN sed -i '/en_US.UTF-8/s/^# //g' /etc/locale.gen && locale-gen

ENV LANG en_US.UTF-8
ENV LANGUAGE en_US:en
ENV LC_ALL en_US.UTF-8

WORKDIR "/app"
RUN chown nobody /app

# set runner ENV
ENV MIX_ENV="prod"

# Only copy the final release from the build stage
COPY --from=builder --chown=nobody:root /app/_build/${MIX_ENV}/rel/inbubbles ./

USER nobody

CMD ["/app/bin/server"]

Many thanks!

4

I’m running into a similar issue and am also investigating. I am not sure whether the error I’m hitting locally is the same as the error I’m hitting on Fly.io, because I’m getting zero information from Fly.io:

May 21, 2024 @ 23:54:07.391332364 Machine started in 487ms
May 21, 2024 @ 23:54:09.210436310 Runtime terminating during boot (terminating)
May 21, 2024 @ 23:54:09.384395360 Crash dump is being written to: erl_crash.dump...done
May 21, 2024 @ 23:54:09.465864450 e[32m INFOe[0m Main child exited normally with code: 1

Their support says there is no way for me to get erl_crash.dump.

I’ll update here if I find anything.

5

Setting FLY_APP_NAME, FLY_PRIVATE_IP, and FLY_IMAGE_REF allowed me to run the Docker image. It’s very unclear to me where RELEASE_NODE is even consumed. The only reference I could find in the Elixir source code has zero comments: elixir/lib/mix/lib/mix/tasks/release.init.ex at 1b6c31a0eb6ebba2590bae78b6413ab5b9145139 · elixir-lang/elixir · GitHub

UPDATE: I assume it’s being read here, inside of the start case in the script that mix release generates:

For a dev release I see it at _build/dev/rel/foo/bin/foo. There is a little bit of documentation here: mix release — Mix v1.16.3