Jemalloc error on new app

Questions / Help
1

Hi, I’ve been trying to deploy an app and I keep seeing this in the logs and on ssh ERROR: ld.so: object '/usr/lib/aarch64-linux-gnu/libjemalloc.so.2' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored

I’ve followed the guides and it doesn’t seem to work. What I’m doing wrong ?

For reference here’s my Dockerfile:

# syntax = docker/dockerfile:1

# Make sure RUBY_VERSION matches the Ruby version in .ruby-version and Gemfile
ARG RUBY_VERSION=3.2.2
FROM ruby:$RUBY_VERSION-slim as base

LABEL fly_launch_runtime="rails"

# Rails app lives here
WORKDIR /rails

# Set production environment
ENV RAILS_ENV="production" \
    BUNDLE_WITHOUT="development:test" \
    BUNDLE_DEPLOYMENT="1"

# Update gems and bundler
RUN gem update --system --no-document && \
    gem install -N bundler


# Throw-away build stage to reduce size of final image
FROM base as build

# Install packages needed to build gems and node modules
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y build-essential curl libpq-dev libvips node-gyp pkg-config python-is-python3

# Install JavaScript dependencies
ARG NODE_VERSION=20.3.0
ARG YARN_VERSION=1.22.17
ENV PATH=/usr/local/node/bin:$PATH
RUN curl -sL https://github.com/nodenv/node-build/archive/master.tar.gz | tar xz -C /tmp/ && \
    /tmp/node-build-master/bin/node-build "${NODE_VERSION}" /usr/local/node && \
    npm install -g yarn@$YARN_VERSION && \
    rm -rf /tmp/node-build-master

# Install application gems
COPY --link Gemfile Gemfile.lock ./
RUN bundle install && \
    bundle exec bootsnap precompile --gemfile && \
    rm -rf ~/.bundle/ $BUNDLE_PATH/ruby/*/cache $BUNDLE_PATH/ruby/*/bundler/gems/*/.git

# Install node modules
COPY --link package.json yarn.lock ./
RUN yarn install --frozen-lockfile

# Copy application code
COPY --link . .

# Precompile bootsnap code for faster boot times
RUN bundle exec bootsnap precompile app/ lib/

# Adjust binfiles to set current working directory
RUN grep -l '#!/usr/bin/env ruby' /rails/bin/* | xargs sed -i '/^#!/aDir.chdir File.expand_path("..", __dir__)'

# Precompiling assets for production without requiring secret RAILS_MASTER_KEY
RUN SECRET_KEY_BASE=DUMMY ./bin/rails assets:precompile


# Final stage for app image
FROM base

# Install packages needed for deployment
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y curl imagemagick libjemalloc2 libvips postgresql-client sudo && \
    rm -rf /var/lib/apt/lists /var/cache/apt/archives

# Copy built artifacts: gems, application
COPY --from=build /usr/local/bundle /usr/local/bundle
COPY --from=build /rails /rails

# Run and own only the runtime files as a non-root user for security
RUN useradd rails --create-home --shell /bin/bash && \
    sed -i 's/env_reset/env_keep="*"/' /etc/sudoers && \
    chown -R rails:rails db log storage tmp
USER rails:rails

# Deployment options

ENV LD_PRELOAD="/usr/lib/aarch64-linux-gnu/libjemalloc.so.2" \
    MALLOC_CONF="dirty_decay_ms:1000,narenas:2,background_thread:true" \
    RAILS_LOG_TO_STDOUT="1" \
    RAILS_SERVE_STATIC_FILES="true"

# Entrypoint prepares the database.
ENTRYPOINT ["/rails/bin/docker-entrypoint"]

# Start the server by default, this can be overwritten at runtime
EXPOSE 3000
CMD ["./bin/rails", "server"]
2

You are running on a Mac M1/M2. Try the following:

bin/rails generate dockerfile --platform=linux/amd64
3

Usually for debian images I use LD_PRELOAD="libjemalloc.so.2" and Linux is capable of resolving the lib prefix.

4

Thanks! Let Linux resolve the path to jemalloc · fly-apps/dockerfile-rails@85822c2 · GitHub

1 Like
5

awesome, it worked thanks!

6

At this point, dockerfile-rails is probably one of the most useful gems in the rails world!

1 Like
7

Thanks! Real world usage is a great way to converge on something useful.

Somebody reports a problem. Somebody suggests a change to their Dockerfile to solve the problem. Somebody changes the generator to incorporate this change so future users won’t have this problem.

In general, computers are good at if checks.

In the future, feel free to be the person who changes the generator. Pull requests welcome!

1 Like
8

This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.