Build the Ruby layer for both x86_64 and arm64

.github/actions/build-ruby-layer/action.yml

@@ -12,17 +12,21 @@ outputs:
 runs:
   using: composite
   steps:
-    - name: Build Ruby layer
-      shell: bash
-      working-directory: ruby/src
-      run: ./build.sh
-
     - name: Save Ruby OpenTelemetry SDK version
       id: version
       shell: bash
       working-directory: ruby/src
       run: |
-        unzip -q build/opentelemetry-ruby-layer.zip
-        export GEM_PATH=$PWD/ruby/gems/3.3.0/
-        SDK_VERSION=$(ruby -e 'require "opentelemetry-sdk"; puts OpenTelemetry::SDK::VERSION')
+        SDK_VERSION=$(sed -n 's/^    opentelemetry-sdk (\([^)]*\))$/\1/p' otel/layer/Gemfile.lock)
         echo "component-version=$SDK_VERSION" >> "$GITHUB_OUTPUT"
+
+    # The layer also contains arm64 gems, built in emulated arm64 stages.
+    - name: Set up QEMU
+      uses: docker/setup-qemu-action@99012661954931238ded8c8b007157a8430204e1 # v4.4.0
+      with:
+        platforms: arm64
+
+    - name: Build Ruby layer
+      shell: bash
+      working-directory: ruby/src
+      run: ./build.sh

.github/workflows/ci-ruby.yml

@@ -5,12 +5,14 @@ on:
     paths:
       - 'ruby/**'
       - '.github/workflows/ci-ruby.yml'
+      - '.github/actions/build-ruby-layer/**'
     branches:
       - main
   pull_request:
     paths:
       - 'ruby/**'
       - '.github/workflows/ci-ruby.yml'
+      - '.github/actions/build-ruby-layer/**'
     branches:
       - main
 
@@ -25,6 +27,4 @@ jobs:
         with:
           persist-credentials: false
       - name: Build Ruby layer
-        shell: bash
-        working-directory: ruby/src
-        run: ./build.sh
+        uses: $/.github/actions/build-ruby-layer

integration-tests/tests/layer.test.ts

@@ -24,6 +24,7 @@ describe(`${language} Lambda layer`, () => {
       }),
     );
     expect(response.StatusCode).toBe(200);
+    expect(response.FunctionError).toBeUndefined();
 
     const payload = JSON.parse(new TextDecoder().decode(response.Payload));
     const body = JSON.parse(payload.body);

ruby/README.md

@@ -3,7 +3,6 @@
 Scripts and files used to build AWS Lambda Layers for running OpenTelemetry on AWS Lambda for Ruby.
 
 **Requirement**
-* Ruby 3.3.0/3.4.0
 * [SAM CLI](https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-cli-install.html)
 * [AWS CLI](https://docs.aws.amazon.com/cli/latest/userguide/install-cliv2.html)
 * [Go](https://go.dev/doc/install)
@@ -17,7 +16,7 @@ Scripts and files used to build AWS Lambda Layers for running OpenTelemetry on A
 ./build.sh
 ```
 
-Layer is stored in `src/build` folder
+Layer is stored in `src/build`. It contains gems for Ruby 3.3 and 3.4 on x86_64 and arm64. Only Docker is needed; building the non-native architecture needs QEMU binfmt (e.g. `docker run --privileged --rm tonistiigi/binfmt --install all`).
 
 **Default GEM_PATH**
 

ruby/src/otel/Dockerfile

@@ -1,60 +1,46 @@
-FROM ubuntu:26.04@sha256:f144425ff09be612d6d9ad965196e9cdc23dae1f42110a8a11a3e9a8198759f7
-
-RUN mkdir /build
-
-COPY . /build
-
-RUN apt-get update && apt-get install -y git curl libssl-dev libreadline-dev zlib1g-dev autoconf bison build-essential libyaml-dev libreadline-dev libncurses5-dev libffi-dev libgdbm-dev zip
-
-RUN  git clone https://github.com/rbenv/rbenv.git ~/.rbenv \
-     && git clone https://github.com/rbenv/ruby-build.git ~/.rbenv/plugins/ruby-build \
-     && git clone https://github.com/rbenv/rbenv-default-gems.git ~/.rbenv/plugins/rbenv-default-gems \
-     && echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.profile \
-     && echo 'eval "$(rbenv init -)"' >> ~/.profile \
-     && echo 'eval "$(rbenv init -)"' >> ~/.bashrc \
-     && echo 'bundler' > ~/.rbenv/default-gems
-
-RUN echo 'alias be="bundle exec"' >> ~/.bashrc
-RUN echo 'alias be="bundle exec"' >> ~/.profile
-
-# install rubies to build our gem against Gemfile
-RUN . ~/.profile \
-   && cd /root/.rbenv/plugins/ruby-build && git pull && cd - \
-   && rbenv install 3.3.0 \
-   && rbenv install 3.4.0
-
-WORKDIR /build/layer
-
-RUN . ~/.profile && rbenv local 3.3.0 && bundle install
-RUN . ~/.profile && rbenv local 3.4.0 && bundle install
-
-WORKDIR /root/.rbenv/versions/3.3.0/lib/ruby/gems/
-RUN zip -r gems-3.3.0.zip 3.3.0/
-
-WORKDIR /root/.rbenv/versions/3.4.0/lib/ruby/gems/
-
-# rbenv install 3.4.0 get 3.4.0+1/, so need to change back to 3.4.0+1
-RUN mv 3.4.0+1/ 3.4.0/
-RUN set -e && \
-  dir=$(find /root/.rbenv/versions/3.4.0/lib/ruby/gems/ -type d -name '3.4.0+1' | head -n 1) && \
-  target=$(echo "$dir" | sed 's/3\.4\.0+1/3.4.0/') && \
-  mv "$dir" "$target"
-RUN zip -r gems-3.4.0.zip 3.4.0/
-
-# copy gems to /build/ruby/gems for zipping 
-RUN mkdir /build/ruby && mkdir /build/ruby/gems
-WORKDIR /build/ruby/gems
-RUN cp /root/.rbenv/versions/3.3.0/lib/ruby/gems/gems-3.3.0.zip . && unzip gems-3.3.0.zip && rm gems-3.3.0.zip
-RUN cp /root/.rbenv/versions/3.4.0/lib/ruby/gems/gems-3.4.0.zip . && unzip gems-3.4.0.zip && rm gems-3.4.0.zip
-RUN ls -al /build/ruby/gems
-
-# rm gem cache
-RUN rm /root/.rbenv/versions/3.3.0/lib/ruby/gems/3.3.0/cache/* \
-    && rm /root/.rbenv/versions/3.4.0/lib/ruby/gems/3.4.0/cache/*
-
-# zip all the gems
+# Builds one layer with gems for Ruby 3.3 and 3.4 on both x86_64 and arm64.
+# RubyGems only activates gem specs whose platform matches the running
+# machine, so both architectures' gems can live side by side in
+# ruby/gems/<X.Y.0>. The four install stages below are independent, so
+# BuildKit runs them in parallel (arm64 via QEMU on amd64 hosts and vice versa).
+
+FROM --platform=linux/amd64 public.ecr.aws/sam/build-ruby3.3:latest@sha256:0e8b401558ba3d59722ea169d0da854631136a23eded32109d6a8ed2345ab0ee AS ruby3.3-amd64
+COPY layer/Gemfile layer/Gemfile.lock install-gems.sh /build/
+RUN /build/install-gems.sh
+
+FROM --platform=linux/arm64 public.ecr.aws/sam/build-ruby3.3:latest@sha256:0e8b401558ba3d59722ea169d0da854631136a23eded32109d6a8ed2345ab0ee AS ruby3.3-arm64
+COPY layer/Gemfile layer/Gemfile.lock install-gems.sh /build/
+RUN /build/install-gems.sh
+
+FROM --platform=linux/amd64 public.ecr.aws/sam/build-ruby3.4:latest@sha256:a208c01413754ea473357ffdc850fab3cdadf6dac776a0566242464dba2aa02b AS ruby3.4-amd64
+COPY layer/Gemfile layer/Gemfile.lock install-gems.sh /build/
+RUN /build/install-gems.sh
+
+FROM --platform=linux/arm64 public.ecr.aws/sam/build-ruby3.4:latest@sha256:a208c01413754ea473357ffdc850fab3cdadf6dac776a0566242464dba2aa02b AS ruby3.4-arm64
+COPY layer/Gemfile layer/Gemfile.lock install-gems.sh /build/
+RUN /build/install-gems.sh
+
+# Final stage only merges and zips, so it runs on the host's native platform.
+FROM public.ecr.aws/sam/build-ruby3.3:latest@sha256:0e8b401558ba3d59722ea169d0da854631136a23eded32109d6a8ed2345ab0ee
 WORKDIR /build
-RUN cp layer/otel-handler . && cp layer/wrapper.rb .
-RUN zip -r opentelemetry-ruby-layer.zip ruby/ otel-handler wrapper.rb
-
-CMD cp /build/opentelemetry-ruby-layer.zip /out/opentelemetry-ruby-layer.zip
+COPY --from=ruby3.3-amd64 /gems/ruby/ amd64/
+COPY --from=ruby3.4-amd64 /gems/ruby/ amd64/
+COPY --from=ruby3.3-arm64 /gems/ruby/ arm64/
+COPY --from=ruby3.4-arm64 /gems/ruby/ arm64/
+
+# Paths that exist for both architectures must be identical, otherwise one
+# would overwrite the other in the merged layer. Fail if a (future) native
+# gem brings such a clash back.
+RUN if diff -rq amd64 arm64 2>&1 | grep -v '^Only in '; then \
+      echo "ERROR: amd64 and arm64 gem trees clash on the paths above" >&2; exit 1; \
+    fi
+
+RUN mkdir -p ruby/gems \
+    && cp -a amd64/. ruby/gems/ \
+    && cp -a arm64/. ruby/gems/
+
+COPY layer/otel-handler ./
+COPY layer/wrapper.rb ./
+RUN zip -qr opentelemetry-ruby-layer.zip ruby/ otel-handler wrapper.rb
+
+CMD ["cp", "/build/opentelemetry-ruby-layer.zip", "/out/opentelemetry-ruby-layer.zip"]

ruby/src/otel/install-gems.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+# Installs the layer's gems for the Ruby version and architecture of the
+# current build image into /gems/ruby/<X.Y.0>, keeping only what ships.
+set -eu
+
+# Without this RubyGems also copies compiled extensions (e.g. bigdecimal.so)
+# into gems/<name>/lib/, an arch-agnostic path that would clash between
+# amd64 and arm64. The copy under extensions/<arch>-linux/ is enough.
+echo "install_extension_in_lib: false" > ~/.gemrc
+
+# BUNDLE_VERSION=system: use the image's Bundler instead of installing the
+# lockfile's "BUNDLED WITH" version into the layer.
+cd /build
+BUNDLE_PATH=/gems BUNDLE_FROZEN=true BUNDLE_VERSION=system \
+  bundle install --jobs "$(nproc)"
+
+# Drop download cache, docs, build leftovers, binstubs and build logs.
+cd /gems/ruby/*/
+rm -rf cache doc build_info bin plugins gems/*/ext
+find extensions \( -name mkmf.log -o -name gem_make.out \) -delete