ArgumentError: pathname contains null byte - prawn - docker - ruby

Question

I'm currently working on a Rails 5.2 application. In the Dockerfile I'm using ruby:2.5-alpine. when running the following code
pdf_attached_doc.image signature_image I get the following error.
ArgumentError: pathname contains null byte
from /usr/local/bundle/gems/prawn-2.2.2/lib/prawn/images.rb:148:in `initialize'
I tried brew prune and brew update without success. Here is my Dockerfile
FROM ruby:2.5-alpine
# Bare minimum dependencies for our Rails App with the Apline image;
# build-base, git, nodejs, linux-headers, postgresql-dev, tzdata
#
# Project dependencies include;
# pdftk
RUN apk add --no-cache --update \
bash \
build-base \
git \
nodejs \
pdftk \
postgresql-dev \
tzdata \
less
# Set the working directory for all commands after this
WORKDIR /app
# Bundle the application
# Copy our Gemfiles into the app directory and install
ADD ./rails_app/Gemfile \
./rails_app/Gemfile.lock \
/app/
RUN bundle install
Here is my Gemfile
# frozen_string_literal: true
source 'https://rubygems.org'
git_source(:github) { |repo| "https://github.com/#{repo}.git" }
ruby '2.5.1'
# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '~> 5.2.0'
# Use postgresql as the database for Active Record
gem 'pg'
# Loads environment variables from `.env`.
gem 'dotenv-rails', groups: %i[development test]
# Use Puma as the app server
gem 'puma', '~> 3.11'
# Use SCSS for stylesheets
gem 'sass-rails', '~> 5.0'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'mini_racer', platforms: :ruby
# For svg sprites
gem 'svgeez', '~> 1.0', '>= 1.0.3'
# Interact with Box API via Boxr Ruby library.
gem 'boxr'
# Use CoffeeScript for .coffee assets and views
gem 'coffee-rails', '~> 4.2'
# Turbolinks makes navigating your web application faster.
# Read more: https://github.com/turbolinks/turbolinks
gem 'turbolinks', '~> 5'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.5'
# jquery-rails
gem 'jquery-rails', '~> 4.3', '>= 4.3.3'
# PDF merger
gem 'combine_pdf', '~> 1.0', '>= 1.0.14'
# PDF parse into form
gem 'pdf-forms', '~> 1.1', '>= 1.1.1'
# Add PNG, JPEG and Other images to PDF
gem 'prawn', '~> 2.1'
# Use Redis adapter to run Action Cable in production
# gem 'redis', '~> 4.0'
# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'
# Parse address
# Use httparty for requests
gem 'httparty', '~> 0.16.2'
# Use ActiveStorage variant
# gem 'mini_magick', '~> 4.8'
gem 'pry-rails', group: :development
# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development
# Reduces boot times through caching; required in config/boot.rb
gem 'bootsnap', '>= 1.1.0', require: false
group :development, :test do
gem 'byebug', platforms: %i[mri mingw x64_mingw]
end
group :development do
gem 'listen', '>= 3.0.5', '< 3.2'
gem 'web-console', '>= 3.3.0'
# Spring speeds up development by keeping your application running
# in the background. Read more: https://github.com/rails/spring
gem 'rubocop', '~> 0.59.1', require: false
gem 'spring'
gem 'spring-watcher-listen', '~> 2.0.0'
end
group :test do
# Adds support for Capybara system testing and selenium driver
gem 'capybara', '>= 2.15', '< 4.0'
gem 'selenium-webdriver'
# Easy installation and use of chromedriver to run system tests with Chrome
gem 'chromedriver-helper'
end
# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem 'tzinfo-data', platforms: %i[mingw mswin x64_mingw jruby]
Any help?

Answer 1

I don't understand docker with proficiency. But, all times that i had this error with ruby, is because on the situation i'ved been send a file in verification. The solution for those issues are send the file path instead the file.