feat: add docker files for testing

Dockerfile

@@ -0,0 +1,43 @@
+ARG RUBY_VERSION
+
+FROM ruby:${RUBY_VERSION}-slim
+
+ARG GROUPNAME=docker
+ARG USERNAME=docker
+ARG UID
+ARG GID
+ARG RUNTIME_PACKAGES="git less"
+ARG BUILD_PACKAGES="build-essential"
+ARG WORKSPACE_DIR=/workspace
+ARG WORKSPACE_CONTAINER_DIR=/workspace-container
+
+RUN set -x \
+ && groupadd -g ${GID} ${GROUPNAME} \
+ && useradd -u ${UID} -g ${GROUPNAME} -m ${USERNAME}
+
+RUN set -x \
+ && apt-get -y update \
+ && apt-get -y upgrade \
+ && apt-get -y install --no-install-recommends ${RUNTIME_PACKAGES} ${BUILD_PACKAGES}
+
+RUN set -x \
+ && mkdir -p ${WORKSPACE_DIR} \
+ && chown -R ${UID}:${GID} ${WORKSPACE_DIR}
+WORKDIR ${WORKSPACE_DIR}
+
+RUN set -x \
+ && mkdir -p ${WORKSPACE_CONTAINER_DIR} \
+ && chown -R ${UID}:${GID} ${WORKSPACE_CONTAINER_DIR}
+
+COPY --chown=${UID}:${GID} . .
+
+USER ${UID}
+
+RUN set -x \
+ && gem install bundler \
+ && bundle config path ${WORKSPACE_CONTAINER_DIR}/vendor/bundle \
+ && bundle install \
+ && mv Gemfile.lock ${WORKSPACE_CONTAINER_DIR}
+
+ENV WORKSPACE_CONTAINER_DIR=${WORKSPACE_CONTAINER_DIR}
+ENTRYPOINT ["/workspace/entrypoint.sh"]

docker-compose.yml

@@ -0,0 +1,37 @@
+x-base:
+  base: &base
+    build: &build
+      context: .
+      args: &build-args
+        UID: 1000
+        GID: 1000
+    volumes:
+      - .:/workspace
+
+services:
+  "3.1":
+    <<: *base
+    image: rspec-context_helper.rb:3.1
+    build:
+      <<: *build
+      args:
+        <<: *build-args
+        RUBY_VERSION: 3.1
+
+  "3.0":
+    <<: *base
+    image: rspec-context_helper.rb:3.0
+    build:
+      <<: *build
+      args:
+        <<: *build-args
+        RUBY_VERSION: 3.0
+
+  "2.7":
+    <<: *base
+    image: rspec-context_helper.rb:2.7
+    build:
+      <<: *build
+      args:
+        <<: *build-args
+        RUBY_VERSION: 2.7

entrypoint.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+cleanup() {
+  rm Gemfile.lock
+}
+trap cleanup EXIT
+
+ln -sf ${WORKSPACE_CONTAINER_DIR}/Gemfile.lock .
+$@