feat(examples): move examples to a nested WORKSPACE (#337)

This lets users understand the example in isolation. They can copy/paste the example directory
and it works correctly.

This refactors the existing examples which are quite weak, only really demonstrating pip usage.
This makes room for examples demonstrating other features (like protocol buffers) or package
managers (like poetry).

In a later commit I'll add bazel-integration-testing so we get a test target that confirms
the examples build (including their WORKSPACE being self-contained)

Author: alexeagle

.bazelrc

@@ -0,0 +1,8 @@
+# For bazel-in-bazel testing
+# Trick bazel into treating BUILD files under examples/* and e2e/* as being regular files
+# This lets us glob() up all the files inside the examples to make them inputs to tests
+# (Note, we cannot use `common --deleted_packages` because the bazel version command doesn't support it)
+# To update these lines, run this command:
+# sed -i.bak "/^[^#].*--deleted_packages/s#=.*#=$(find examples/*/* \( -name BUILD -or -name BUILD.bazel \) | xargs -n 1 dirname | paste -sd, -)#" .bazelrc && rm .bazelrc.bak
+build --deleted_packages=examples/pip/boto,examples/pip/extras,examples/pip/helloworld
+query --deleted_packages=examples/pip/boto,examples/pip/extras,examples/pip/helloworld

examples/pip/README.md

@@ -0,0 +1,5 @@
+# pip example
+
+This shows how you can point Bazel at your requirements.txt file to get dependencies automatically installed.
+
+It also shows how a monorepo might have multiple python packages which each have a separate requirements.txt file.

examples/pip/WORKSPACE

@@ -0,0 +1,41 @@
+workspace(name = "pip_example")
+
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+http_archive(
+    name = "rules_python",
+    url = "https://github.com/bazelbuild/rules_python/releases/download/0.0.2/rules_python-0.0.2.tar.gz",
+    strip_prefix = "rules_python-0.0.2",
+    sha256 = "b5668cde8bb6e3515057ef465a35ad712214962f0b3a314e551204266c7be90c",
+)
+
+load("@rules_python//python:pip.bzl", "pip_import", "pip_repositories")
+
+pip_repositories()
+
+pip_import(
+    name = "helloworld_deps",
+    requirements = "//helloworld:requirements.txt",
+)
+
+load("@helloworld_deps//:requirements.bzl", _helloworld_install = "pip_install")
+
+_helloworld_install()
+
+pip_import(
+    name = "boto_deps",
+    requirements = "//boto:requirements.txt",
+)
+
+load("@boto_deps//:requirements.bzl", _boto_install = "pip_install")
+
+_boto_install()
+
+pip_import(
+    name = "extras_deps",
+    requirements = "//extras:requirements.txt",
+)
+
+load("@extras_deps//:requirements.bzl", _extras_install = "pip_install")
+
+_extras_install()

examples/boto/BUILD examples/pip/boto/BUILDexamples/boto/BUILD renamed to examples/pip/boto/BUILD

@@ -12,8 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-load("@examples_boto//:requirements.bzl", "requirement")
-load("//python:defs.bzl", "py_test")
+load("@boto_deps//:requirements.bzl", "requirement")
+load("@rules_python//python:defs.bzl", "py_test")
 
 package(default_visibility = ["//visibility:public"])
 

examples/boto/boto_test.py examples/pip/boto/boto_test.pyexamples/boto/boto_test.py renamed to examples/pip/boto/boto_test.py

@@ -13,13 +13,18 @@
 # limitations under the License.
 
 import boto3
+import pip
 import unittest
 
 
 class BotoTest(unittest.TestCase):
 
   def test_version(self):
+    # Just the minimal assertion that the boto3 import worked
     self.assertEqual(boto3.__version__, '1.4.7')
+    # Regression test that the pip version is the one requested
+    # see https://github.com/bazelbuild/rules_python/pull/1#discussion_r138349892
+    self.assertEqual(pip.__version__, '9.0.3')
 
 
 if __name__ == '__main__':

examples/boto/requirements.txt examples/pip/boto/requirements.txtexamples/boto/requirements.txt renamed to examples/pip/boto/requirements.txt

@@ -2,3 +2,4 @@ boto3==1.4.7
 # Release 0.15 appears to have a broken wheel.
 # See https://github.com/bazelbuild/rules_python/issues/205.
 docutils!=0.15.post1
+pip==9.0.3

examples/extras/BUILD examples/pip/extras/BUILDexamples/extras/BUILD renamed to examples/pip/extras/BUILD

@@ -12,8 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-load("@examples_extras//:requirements.bzl", "requirement")
-load("//python:defs.bzl", "py_test")
+load("@extras_deps//:requirements.bzl", "requirement")
+load("@rules_python//python:defs.bzl", "py_test")
 
 package(default_visibility = ["//visibility:public"])