re-architect application to use Lambda with Docker, replacing Lambda layers

Author: Colby Swandale

CODE_OF_CONDUCT.md

@@ -1,7 +1,5 @@
 source "https://rubygems.org"
 
-gem "rake"
-
 group :test do
   gem "test-unit"
-end
+end

Gemfile

@@ -1,17 +1,15 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    power_assert (1.2.0)
-    rake (13.0.3)
-    test-unit (3.3.6)
+    power_assert (2.0.1)
+    test-unit (3.5.3)
       power_assert
 
 PLATFORMS
-  ruby
+  arm64-darwin-21
 
 DEPENDENCIES
-  rake
   test-unit
 
 BUNDLED WITH
-   2.1.4
+   2.2.32

Gemfile.lock

@@ -25,36 +25,17 @@ $ sam local start-api
 **Note** The local dev server does not automatically build the Ruby Engine layer that each function depends on. You will need to build the layer beforehand for the engine/version being invoked ie:
 
 ```
-$ sam build MRIRuby27
+$ sam build MRIRuby
 $ sam local start-api
-$ curl http://localhost:3000/exec/mri/27
+$ curl http://localhost:3000/exec/mri
 ```
 
 ## Testing repl function
 
 The test suit is located in `tests` and can be executed with:
 
 ```bash
-$ rake test
-```
-
-## Architecture
-
-Each Ruby engine & version is a single lambda function that contains a small ruby application & a [Lambda layer](https://docs.aws.amazon.com/lambda/latest/dg/configuration-layers.html) that contains the given Ruby engine version's program/binary.
-
-The diagram represents the application flow:
-
-```
-+-----------------+               +-----------------+        Execute Ruby
-|                 |               |                 |            Binary
-|                 |    Execute    |                 +---------+
-|                 |  Lambda func  |                 |         |
-|  HTTP Endpoint  +---------------> Lambda Function |         |
-|                 |               |                 +---------v---------+
-|                 |               |                 |                   |
-|                 |               |                 | Ruby Engine Layer |
-|                 |               |                 |                   |
-+-----------------+               +-----------------+-------------------+
+$ ruby tests/unit/*
 ```
 
 ## Deploy to AWS

LICENSE.md

@@ -0,0 +1,30 @@
+# syntax=docker/dockerfile:1
+FROM public.ecr.aws/lambda/ruby:2.7 as builder
+
+WORKDIR /opt
+
+ARG RUBY_VERSION=3.0.3
+ENV RUBY_CFLAGS="-Os"
+ENV RUBY_CONFIGURE_OPTS="--disable-install-doc"
+
+RUN yum groupinstall -y 'Development Tools' && \
+  yum install -y openssl-devel java-1.8.0-openjdk
+
+RUN git clone https://github.com/rbenv/ruby-build /opt/ruby-build --depth 1 && \
+  /opt/ruby-build/bin/ruby-build ${RUBY_VERSION} /opt/ruby
+
+
+
+FROM public.ecr.aws/lambda/ruby:2.7 as app
+
+ENV GEM_HOME=${LAMBDA_TASK_ROOT}
+
+RUN yum install -y java-1.8.0-openjdk
+
+COPY --from=builder /opt/ruby/ /opt/ruby/
+COPY . ./
+
+RUN bundle install
+
+# Command can be overwritten by providing a different command in the template directly.
+CMD ["app.lambda_handler"]

README.md

@@ -0,0 +1,20 @@
+# syntax=docker/dockerfile:1
+FROM rust as builder
+
+WORKDIR /opt
+
+RUN apt update -qq && apt install -y -qq ruby clang && \
+  cargo install --git https://github.com/artichoke/artichoke \
+  --branch trunk --locked artichoke --root /opt/artichoke
+
+FROM public.ecr.aws/lambda/ruby:2.7 as app
+
+ENV GEM_HOME=${LAMBDA_TASK_ROOT}
+
+COPY --from=builder /opt/artichoke/ /opt/ruby/
+COPY . ./
+
+RUN bundle install
+
+# Command can be overwritten by providing a different command in the template directly.
+CMD ["app.lambda_handler"]

Rakefile

@@ -1,17 +1,14 @@
-# frozen_string_literal: true
-
 require 'json'
 require 'open3'
 
-require_relative './helper'
 require_relative './code_executor'
 
 def lambda_handler(event:, context:)
   event.transform_keys!(&:to_sym)
 
   body = event.fetch(:body)
 
-  return { statusCode: 400, body: {}.to_json } if body.empty?
+  return empty_response if body.empty?
 
   response = CodeExecutor.run(body)
 
@@ -21,3 +18,6 @@ def lambda_handler(event:, context:)
   }
 end
 
+def empty_response
+  { statusCode: 200, body: {} }
+end

app/Dockerfile

@@ -1,49 +1,48 @@
-require_relative './helper'
-require_relative './response'
-require_relative './payload'
-
-require 'open3'
-
-class CodeExecutor
-  include Helper
-
-  attr_accessor :payload
-
-  def self.run(body)
-    new(body).run
-  end
-
-  def initialize(body)
-    @payload = Payload.generate_from_body(body)
-  end
-
-  def run
-    execute_payload
-  end
-
-  private
-
-  def execute_payload
-    stdout, stderr, status = Open3.capture3(ruby_cmd, stdin_data: payload)
-    Response.new(output: stdout, errors: stderr, status: status&.exitstatus)
-  end
-
-  def ruby_cmd
-    [ruby_env, ruby_bin_path, ruby_args].join(" ")
-  end
-
-  # Workaround for SAM overwriting the PATH env
-  def ruby_env
-    "PATH=\"/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/bin:/opt/bin:/opt/java/bin\""
-  end
-
-  def ruby_bin_path
-    ENV["RUBY_BIN"] || `which ruby`.strip
-  end
-
-  def ruby_args
-    return engine_args if engine_args?
-
-    "--disable-did_you_mean --disable-gems"
-  end
+require_relative './payload'
+
+require 'open3'
+
+Response = Struct.new(:output, :errors, :status, keyword_init: true) do
+  def status
+    self[:status] || 0
+  end
+end
+
+class CodeExecutor
+  attr_accessor :payload
+
+  def self.run(body)
+    new(body).run
+  end
+
+  def initialize(body)
+    @payload = Payload.generate_from_body(body)
+  end
+
+  def run
+    execute_payload
+  end
+
+  private
+
+  def execute_payload
+    stdout, stderr, status = Open3.capture3(ruby_cmd, stdin_data: payload)
+    Response.new(output: stdout, errors: stderr, status: status&.exitstatus)
+  end
+
+  def ruby_cmd
+    [ruby_bin_path, ruby_args].join(" ")
+  end
+
+  def ruby_bin_path
+    if ENV["RUBY_BIN_PATH"] && !ENV["RUBY_BIN_PATH"].empty?
+      ENV["RUBY_BIN_PATH"]
+    else
+      "/opt/ruby/bin/ruby"
+    end
+  end
+
+  def ruby_args
+    ENV["ENGINE_ARGS"]
+  end
 end