First, we’ll create a sample Ruby app that you can use when developing your buildpack:
mkdir ruby-sample-app
Create a file in the current directory called ruby-sample-app/app.rb
with the following contents:
require 'sinatra'
set :bind, '0.0.0.0'
set :port, 8080
get '/' do
'Hello World!'
end
Then, create a file called ruby-sample-app/Gemfile
with the following contents:
source "https://rubygems.org"
git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
gem "sinatra"
Finally, make sure your local Docker daemon is running by executing:
docker version
If you see output similar to the following, you’re good to go! Otherwise, start Docker and check again.
Client: Docker Engine - Community
Version: 20.10.9
API version: 1.41
Go version: go1.16.8
Git commit: c2ea9bc
Built: Mon Oct 4 16:08:29 2021
OS/Arch: linux/amd64
Context: default
Experimental: true
Server: Docker Engine - Community
Engine:
Version: 20.10.9
API version: 1.41 (minimum version 1.12)
Go version: go1.16.8
Git commit: 79ea9d3
Built: Mon Oct 4 16:06:34 2021
OS/Arch: linux/amd64
Experimental: false