Support bundler-only runs

.github/workflows/test.yml

@@ -22,7 +22,8 @@ jobs:
           '1.9', '2.0', '2.1', '2.2', '2.3', '2.4', '2.5', '2.6', '2.7', '3.0', '3.1', '3.2', '3.3', ruby-head,
           jruby, jruby-head,
           truffleruby, truffleruby-head,
-          truffleruby+graalvm, truffleruby+graalvm-head
+          truffleruby+graalvm, truffleruby+graalvm-head,
+          system
         ]
         include:
         - { os: windows-2019, ruby: mingw }
@@ -56,13 +57,15 @@ jobs:
         - { os: windows-2022, ruby: truffleruby-head }
         - { os: windows-2022, ruby: truffleruby+graalvm }
         - { os: windows-2022, ruby: truffleruby+graalvm-head }
+        - { os: windows-2022, ruby: system }
 
     name: ${{ matrix.os }} ${{ matrix.ruby }}
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v4
 
     - uses: ./
+      id: setup-ruby
       with:
         ruby-version: ${{ matrix.ruby }}
         bundler-cache: true
@@ -72,6 +75,8 @@ jobs:
       run: |
         # Show PATH with Powershell
         $f, $r = $env:PATH.split([IO.Path]::PathSeparator); $r
+    - name: Ruby prefix output
+      run: echo "${{ steps.setup-ruby.outputs.ruby-prefix }}"
 
     - name: build compiler
       run: |
@@ -107,6 +112,7 @@ jobs:
 
     - run: gem env
     - name: C extension test
+      if: matrix.ruby != 'system'
       run: gem install json -v 2.2.0
     - run: bundle --version
     # This step is redundant with `bundler-cache: true` but is there to check a redundant `bundle install` still works
@@ -129,6 +135,7 @@ jobs:
       if: startsWith(matrix.os, 'windows')
 
     - name: Test `gem github:` in a Gemfile
+      if: matrix.ruby != 'system' || !startsWith(matrix.os, 'ubuntu')
       run: bundle install
       env:
         BUNDLE_GEMFILE: ${{ github.workspace }}/gemfiles/gem_from_github.gemfile

action.yml

@@ -6,7 +6,10 @@ branding:
   icon: download
 inputs:
   ruby-version:
-    description: 'Engine and version to use, see the syntax in the README. Reads from .ruby-version or .tool-versions if unset.'
+    description: |
+      Engine and version to use. Either 'default' (the default), 'system', or a engine/version syntax described in the README.
+      For 'default', reads from .ruby-version or .tool-versions.
+      For 'system', don't install any Ruby and use the first available Ruby on the PATH.
     default: 'default'
   rubygems:
     description: |

bundler.js

@@ -2,7 +2,9 @@ const fs = require('fs')
 const path = require('path')
 const core = require('@actions/core')
 const exec = require('@actions/exec')
+const io = require('@actions/io')
 const cache = require('@actions/cache')
+const semver = require('semver')
 const common = require('./common')
 
 export const DEFAULT_CACHE_VERSION = '0'
@@ -58,7 +60,7 @@ async function afterLockFile(lockFile, platform, engine, rubyVersion) {
   }
 }
 
-export async function installBundler(bundlerVersionInput, rubygemsInputSet, lockFile, platform, rubyPrefix, engine, rubyVersion) {
+export async function installBundler(bundlerVersionInput, rubygemsInputSet, systemRubyUsed, lockFile, platform, rubyPrefix, engine, rubyVersion) {
   let bundlerVersion = bundlerVersionInput
 
   if (rubygemsInputSet && (bundlerVersion === 'default' || bundlerVersion === 'Gemfile.lock')) {
@@ -79,7 +81,21 @@ export async function installBundler(bundlerVersionInput, rubygemsInputSet, lock
   const floatVersion = common.floatVersion(rubyVersion)
 
   if (bundlerVersion === 'default') {
-    if (common.isBundler2dot2Default(engine, rubyVersion)) {
+    if (systemRubyUsed) {
+      if (await io.which('bundle', false)) {
+        bundlerVersion = await getBundlerVersion()
+        if (semver.lt(semver.coerce(bundlerVersion), '2.2.0')) {
+          console.log('Using latest Bundler because the system Bundler is too old')
+          bundlerVersion = 'latest'
+        } else {
+          console.log(`Using system Bundler ${bundlerVersion}`)
+          return bundlerVersion
+        }
+      } else {
+        console.log('Installing latest Bundler as we could not find a system Bundler')
+        bundlerVersion = 'latest'
+      }
+    } else if (common.isBundler2dot2Default(engine, rubyVersion)) {
       if (common.windows && engine === 'ruby' && (common.isStableVersion(engine, rubyVersion) || rubyVersion === 'head')) {
         // https://github.com/ruby/setup-ruby/issues/371
         console.log(`Installing latest Bundler for ${engine}-${rubyVersion} on Windows because bin/bundle does not work in bash otherwise`)
@@ -144,12 +160,38 @@ export async function installBundler(bundlerVersionInput, rubygemsInputSet, lock
   const versionParts = [...bundlerVersion.matchAll(/\d+/g)].length
   const bundlerVersionConstraint = versionParts >= 3 ? bundlerVersion : `~> ${bundlerVersion}.0`
 
-  await exec.exec(gem, ['install', 'bundler', ...force, '-v', bundlerVersionConstraint])
+  const args = ['install', 'bundler', ...force, '-v', bundlerVersionConstraint]
+
+  let stderr = ''
+  try {
+    await exec.exec(gem, args, {
+      listeners: {
+        stderr: (data) => (stderr += data.toString())
+      }
+    })
+  } catch (error) {
+    if (systemRubyUsed && stderr.includes('Gem::FilePermissionError')) {
+      await exec.exec('sudo', [gem, ...args]);
+    } else {
+      throw error
+    }
+  }
 
   return bundlerVersion
 }
 
-export async function bundleInstall(gemfile, lockFile, platform, engine, rubyVersion, bundlerVersion, cacheVersion) {
+async function getBundlerVersion() {
+  let bundlerVersion = ''
+  await exec.exec('bundle', ['--version'], {
+    silent: true,
+    listeners: {
+      stdout: (data) => (bundlerVersion += data.toString())
+    }
+  })
+  return bundlerVersion.replace(/^Bundler version /, '').trim()
+}
+
+export async function bundleInstall(gemfile, lockFile, platform, engine, rubyVersion, bundlerVersion, cacheVersion, systemRubyUsed) {
   if (gemfile === null) {
     console.log('Could not determine gemfile path, skipping "bundle install" and caching')
     return false
@@ -182,7 +224,7 @@ export async function bundleInstall(gemfile, lockFile, platform, engine, rubyVer
 
   // cache key
   const paths = [cachePath]
-  const baseKey = await computeBaseKey(platform, engine, rubyVersion, lockFile, cacheVersion)
+  const baseKey = await computeBaseKey(platform, engine, rubyVersion, lockFile, cacheVersion, systemRubyUsed)
   const key = `${baseKey}-${await common.hashFile(lockFile)}`
   // If only Gemfile.lock changes we can reuse part of the cache, and clean old gem versions below
   const restoreKeys = [`${baseKey}-`]
@@ -232,7 +274,7 @@ export async function bundleInstall(gemfile, lockFile, platform, engine, rubyVer
   return true
 }
 
-async function computeBaseKey(platform, engine, version, lockFile, cacheVersion) {
+async function computeBaseKey(platform, engine, version, lockFile, cacheVersion, systemRubyUsed) {
   const cwd = process.cwd()
   const bundleWith = process.env['BUNDLE_WITH'] || ''
   const bundleWithout = process.env['BUNDLE_WITHOUT'] || ''
@@ -259,6 +301,19 @@ async function computeBaseKey(platform, engine, version, lockFile, cacheVersion)
     }
   }
 
+  if (systemRubyUsed) {
+    let platform = ''
+    await exec.exec('ruby', ['-e', 'print RUBY_PLATFORM'], {
+      silent: true,
+      listeners: {
+        stdout: (data) => {
+          platform += data.toString();
+        }
+      }
+    });
+    key += `-platform-${platform}`
+  }
+
   key += `-${lockFile}`
   return key
 }