[drake_bazel_external_legacy] Add as fork of non-legacy repository

The legacy example will show how to use WORKSPACE.
The existing (non-legacy) example will switch to use MODULE soon.

At the moment, all sources except README.md must remain identical
across the two copies (per the file_sync_test). As we port to use
bzlmod, a few files will start to differ and will be removed from
the sync.

Jenkinsfile

@@ -45,6 +45,49 @@ node('linux-jammy-unprovisioned') {
     }
   }
 }
+node('linux-jammy-unprovisioned') {
+  timeout(600) {
+    ansiColor('xterm') {
+      def triggers = []
+      if (env.BRANCH_NAME == 'main') {
+        triggers << cron('H H(7-8) * * *')
+      }
+      properties ([
+        pipelineTriggers(triggers)
+      ])
+      try {
+        dir('src') {
+          stage('checkout') {
+            checkout scm
+          }
+        }
+        dir('src/drake_bazel_external_legacy'){
+          stage('bazel_external_legacy setup') {
+            sh '.github/setup'
+          }
+          stage('bazel_external_legacy build and test') {
+            sh '.github/ci_build_test'
+          }
+        }
+      } catch (e) {
+        if (env.BRANCH_NAME == 'main') {
+          emailext (
+            subject: "Build failed in Jenkins: ${env.JOB_NAME} #${env.BUILD_NUMBER}",
+            body: "See <${env.BUILD_URL}display/redirect?page=changes>",
+            recipientProviders: [[$class: 'DevelopersRecipientProvider']],
+            to: '$DEFAULT_RECIPIENTS',
+          )
+        }
+        throw e
+      } finally {
+        deleteDir()
+        dir("${env.WORKSPACE}@tmp") {
+          deleteDir()
+        }
+      }
+    }
+  }
+}
 node('linux-jammy-unprovisioned') {
   timeout(600) {
     ansiColor('xterm') {

drake_bazel_external/README.md

@@ -1,6 +1,9 @@
 # Bazel Project with Drake as an External
 
-This pulls in Drake via the Bazel workspace mechanism.
+This pulls in Drake and builds it from source via Bazel's WORKSPACE mechanism,
+which is deprecated as of Bazel 8 and will be removed in Bazel 9. Therefore,
+we will be rewriting this example to use Bazel modules ("bzlmod") in the near
+future. Stay tuned!
 
 For an introduction to Bazel, refer to
 [Getting Started with Bazel](https://bazel.build/start).

drake_bazel_external_legacy/.bazelignore

@@ -0,0 +1,2 @@
+# Used for setup, do not build
+drake-master

drake_bazel_external_legacy/.bazelproject

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: MIT-0
+
+directories:
+  .
+
+targets:
+  //...:all

drake_bazel_external_legacy/.bazelrc

@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: MIT-0
+
+# Don't use bzlmod yet.
+common --enable_workspace=true
+common --enable_bzlmod=false
+
+# Default to an optimized build.
+build --compilation_mode=opt
+
+# Default build options.
+build --strip=never
+
+# Default test options.
+build --test_output=errors
+build --test_summary=terse
+
+# Use C++20.
+build --cxxopt=-std=c++20
+build --host_cxxopt=-std=c++20
+
+# https://github.com/bazelbuild/bazel/issues/1164
+build --action_env=CCACHE_DISABLE=1
+
+# For Ubuntu builds, this flag can cut build times in half. For macOS builds,
+# this flag might cause build errors. We suggest turning it on if and only if
+# your project doesn't use macOS.
+## build --force_pic=yes
+
+# TODO(jwnimmer-tri) We should see if we can reuse more of Drake's
+# customizations somehow.
+
+# Try to import user-specific configuration local to workspace.
+try-import %workspace%/user.bazelrc

drake_bazel_external_legacy/.bazelversion

@@ -0,0 +1 @@
+8.0.0

drake_bazel_external_legacy/.clang-format

@@ -0,0 +1,22 @@
+# -*- mode: yaml -*-
+# vi: set ft=yaml :
+# SPDX-License-Identifier: MIT-0
+
+---
+BasedOnStyle: Google
+---
+Language: Cpp
+DerivePointerAlignment: false
+PointerAlignment: Left
+
+IncludeCategories:
+  - Regex:    '^[<"](aio|arpa/inet|assert|complex|cpio|ctype|curses|dirent|dlfcn|errno|fcntl|fenv|float|fmtmsg|fnmatch|ftw|glob|grp|iconv|inttypes|iso646|langinfo|libgen|limits|locale|math|monetary|mqueue|ndbm|netdb|net/if|netinet/in|netinet/tcp|nl_types|poll|pthread|pwd|regex|sched|search|semaphore|setjmp|signal|spawn|stdalign|stdarg|stdatomic|stdbool|stddef|stdint|stdio|stdlib|stdnoreturn|string|strings|stropts|sys/ipc|syslog|sys/mman|sys/msg|sys/resource|sys/select|sys/sem|sys/shm|sys/socket|sys/stat|sys/statvfs|sys/time|sys/times|sys/types|sys/uio|sys/un|sys/utsname|sys/wait|tar|term|termios|tgmath|threads|time|trace|uchar|ulimit|uncntrl|unistd|utime|utmpx|wchar|wctype|wordexp)\.h[">]$'
+    Priority: 10
+  - Regex:    '^[<"](algorithm|array|atomic|bitset|cassert|ccomplex|cctype|cerrno|cfenv|cfloat|chrono|cinttypes|ciso646|climits|clocale|cmath|codecvt|complex|condition_variable|csetjmp|csignal|cstdalign|cstdarg|cstdbool|cstddef|cstdint|cstdio|cstdlib|cstring|ctgmath|ctime|cuchar|cwchar|cwctype|deque|exception|forward_list|fstream|functional|future|initializer_list|iomanip|ios|iosfwd|iostream|istream|iterator|limits|list|locale|map|memory|mutex|new|numeric|ostream|queue|random|ratio|regex|scoped_allocator|set|shared_mutex|sstream|stack|stdexcept|streambuf|string|strstream|system_error|thread|tuple|type_traits|typeindex|typeinfo|unordered_map|unordered_set|utility|valarray|vector)[">]$'
+    Priority: 20
+  - Regex:    '^<'
+    Priority: 30
+  - Regex:    '^"(drake|drake_external_examples)'
+    Priority: 50
+  - Regex:    '^"'
+    Priority: 40

drake_bazel_external_legacy/.github/ci_build_test

@@ -0,0 +1,7 @@
+#!/bin/bash
+# SPDX-License-Identifier: MIT-0
+
+set -euxo pipefail
+
+bazel version
+bazel test //...

drake_bazel_external_legacy/.github/setup

@@ -0,0 +1,10 @@
+#!/bin/bash
+# SPDX-License-Identifier: MIT-0
+
+set -euxo pipefail
+
+# CI setup
+sudo .github/ubuntu_setup
+
+# drake source setup
+setup/install_prereqs

drake_bazel_external_legacy/.github/ubuntu_setup

@@ -0,0 +1,22 @@
+#!/bin/bash
+# SPDX-License-Identifier: MIT-0
+
+set -euxo pipefail
+
+if [[ "${EUID:-}" -ne 0 ]]; then
+  echo 'This script must be run as root' >&2
+  exit 2
+fi
+
+echo 'APT::Acquire::Retries "4";' > /etc/apt/apt.conf.d/80-acquire-retries
+echo 'APT::Get::Assume-Yes "true";' > /etc/apt/apt.conf.d/90-get-assume-yes
+
+export DEBIAN_FRONTEND='noninteractive'
+
+apt-get update
+apt-get install --no-install-recommends lsb-release
+
+if [[ "$(lsb_release -sc)" != 'jammy' ]]; then
+  echo 'This script requires Ubuntu 22.04 (Jammy)' >&2
+  exit 3
+fi

drake_bazel_external_legacy/.gitignore

@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: MIT-0
+
+/bazel-*
+/user.bazelrc

drake_bazel_external_legacy/BUILD.bazel

@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: MIT-0
+
+# This is an empty BUILD file, to ensure that this project's root directory is
+# a Bazel package.

drake_bazel_external_legacy/CPPLINT.cfg

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: MIT-0
+
+set noparent
+
+filter=-build/c++11
+filter=-build/header_guard
+filter=-build/include_subdir

drake_bazel_external_legacy/LICENSE

@@ -0,0 +1,16 @@
+Copyright (c) 2017-2023 by the drake-external-examples developers.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

drake_bazel_external_legacy/README.md

@@ -0,0 +1,41 @@
+# Bazel Project with Drake as an External (legacy style)
+
+This pulls in Drake and builds it from source via Bazel's WORKSPACE mechanism,
+which is deprecated as of Bazel 8 and will be removed in Bazel 9. Therefore,
+we do not recommend using this example for new projects; instead, refer to
+the `drake_bazel_external` example. The legacy example primarily serves
+as a regression test for the deprecated behavior.
+
+For an introduction to Bazel, refer to
+[Getting Started with Bazel](https://bazel.build/start).
+
+## Instructions
+
+First, run the `install_prereqs` script to download the drake source and run
+drake's source setup script to install the required Ubuntu packages:
+
+```
+setup/install_prereqs.sh
+```
+
+Then, to build and test all apps:
+```
+bazel test //...
+```
+
+As an example to run a binary directly:
+```
+bazel run //apps:simple_logging_example
+```
+
+You may also run the binary directly per the `bazel-bin/...` path that the
+above command prints out; however, be aware that your working directories may
+cause differences.  This is important when using tools like
+`drake::FindResource` / `pydrake.common.FindResource`.
+You may generally want to stick to using `bazel run` when able.
+
+## Python Versions
+
+By default, Python 3 is the Python interpreter that Drake will use when built
+with Bazel. To see which Python versions are supported, see the
+[supported configurations](https://drake.mit.edu/developers.html#supported-configurations).

drake_bazel_external_legacy/WORKSPACE

@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: MIT-0
+
+workspace(name = "drake_external_examples")
+
+DRAKE_COMMIT = "master"
+DRAKE_CHECKSUM = ""
+
+# Or choose a specific revision of Drake to use.
+# DRAKE_COMMIT = "be4f658487f739ba04ec079de46f9459b719636d"
+# DRAKE_CHECKSUM = "31ec8f87df3ceb6516de3c33a14c5d59ac5c003b4faf93ac526877d2e150b394"
+#
+# You can also use DRAKE_COMMIT to choose a Drake release; eg:
+# DRAKE_COMMIT = "v0.15.0"
+#
+# Before changing the COMMIT, temporarily uncomment the next line so that Bazel
+# displays the suggested new value for the CHECKSUM.
+# DRAKE_CHECKSUM = "0" * 64
+
+# Or to temporarily build against a local checkout of Drake, at the bash prompt
+# set an environment variable before building:
+#  export EXAMPLES_LOCAL_DRAKE_PATH=/home/user/stuff/drake
+
+# Load an environment variable.
+load("//:environ.bzl", "environ_repository")
+environ_repository(name = "environ", vars = ["EXAMPLES_LOCAL_DRAKE_PATH"])
+load("@environ//:environ.bzl", EXAMPLES_LOCAL_DRAKE_PATH = "EXAMPLES_LOCAL_DRAKE_PATH")
+
+# This declares the `@drake` repository as an http_archive from github,
+# iff EXAMPLES_LOCAL_DRAKE_PATH is unset.  When it is set, this declares a
+# `@drake_ignored` package which is never referenced, and thus is ignored.
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+http_archive(
+    name = "drake" if not EXAMPLES_LOCAL_DRAKE_PATH else "drake_ignored",
+    urls = [x.format(DRAKE_COMMIT) for x in [
+        "https://github.com/RobotLocomotion/drake/archive/{}.tar.gz",
+    ]],
+    sha256 = DRAKE_CHECKSUM,
+    strip_prefix = "drake-{}".format(DRAKE_COMMIT.lstrip("v")),
+)
+
+# This declares the `@drake` repository as a local directory,
+# iff EXAMPLES_LOCAL_DRAKE_PATH is set.  When it is unset, this declares a
+# `@drake_ignored` package which is never referenced, and thus is ignored.
+local_repository(
+    name = "drake" if EXAMPLES_LOCAL_DRAKE_PATH else "drake_ignored",
+    path = EXAMPLES_LOCAL_DRAKE_PATH,
+)
+print("Using EXAMPLES_LOCAL_DRAKE_PATH={}".format(EXAMPLES_LOCAL_DRAKE_PATH)) if EXAMPLES_LOCAL_DRAKE_PATH else None  # noqa
+
+# Reference external software libraries, tools, and toolchains per Drake's
+# defaults.  Some software will come from the host system (Ubuntu or macOS);
+# other software will be downloaded in source or binary form from GitHub or
+# other sites.
+load("@drake//tools/workspace:default.bzl", "add_default_workspace")
+add_default_workspace()