diff --git a/python/pip.bzl b/python/pip.bzl
index 237b7d2baa..6b48d8f1e2 100644
--- a/python/pip.bzl
+++ b/python/pip.bzl
@@ -14,25 +14,31 @@
 """Import pip requirements into Bazel."""
 
 def _pip_import_impl(repository_ctx):
-  """Core implementation of pip_import."""
+    """Core implementation of pip_import."""
 
-  # Add an empty top-level BUILD file.
-  # This is because Bazel requires BUILD files along all paths accessed
-  # via //this/sort/of:path and we wouldn't be able to load our generated
-  # requirements.bzl without it.
-  repository_ctx.file("BUILD", "")
+    # Add an empty top-level BUILD file.
+    # This is because Bazel requires BUILD files along all paths accessed
+    # via //this/sort/of:path and we wouldn't be able to load our generated
+    # requirements.bzl without it.
+    repository_ctx.file("BUILD", "")
 
-  # To see the output, pass: quiet=False
-  result = repository_ctx.execute([
-    "python", repository_ctx.path(repository_ctx.attr._script),
-    "--name", repository_ctx.attr.name,
-    "--input", repository_ctx.path(repository_ctx.attr.requirements),
-    "--output", repository_ctx.path("requirements.bzl"),
-    "--directory", repository_ctx.path(""),
-  ])
+    # To see the output, pass: quiet=False
+    result = repository_ctx.execute([
+        "/usr/bin/env",
+        "python3.7",
+        repository_ctx.path(repository_ctx.attr._script),
+        "--name",
+        repository_ctx.attr.name,
+        "--input",
+        repository_ctx.path(repository_ctx.attr.requirements),
+        "--output",
+        repository_ctx.path("requirements.bzl"),
+        "--directory",
+        repository_ctx.path(""),
+    ])
 
-  if result.return_code:
-    fail("pip_import failed: %s (%s)" % (result.stdout, result.stderr))
+    if result.return_code:
+        fail("pip_import failed: %s (%s)" % (result.stdout, result.stderr))
 
 pip_import = repository_rule(
     attrs = {
@@ -93,9 +99,9 @@ Args:
 """
 
 def pip_repositories():
-  """Pull in dependencies needed for pulling in pip dependencies.
+    """Pull in dependencies needed for pulling in pip dependencies.
 
-  A placeholder method that will eventually pull in any dependencies
-  needed to install pip dependencies.
-  """
-  pass
+    A placeholder method that will eventually pull in any dependencies
+    needed to install pip dependencies.
+    """
+    pass
diff --git a/python/whl.bzl b/python/whl.bzl
index 496755671f..b71f1d073a 100644
--- a/python/whl.bzl
+++ b/python/whl.bzl
@@ -14,24 +14,27 @@
 """Import .whl files into Bazel."""
 
 def _whl_impl(repository_ctx):
-  """Core implementation of whl_library."""
+    """Core implementation of whl_library."""
 
-  args = [
-    "python",
-    repository_ctx.path(repository_ctx.attr._script),
-    "--whl", repository_ctx.path(repository_ctx.attr.whl),
-    "--requirements", repository_ctx.attr.requirements,
-  ]
-
-  if repository_ctx.attr.extras:
-    args += [
-      "--extras=%s" % extra
-      for extra in repository_ctx.attr.extras
+    args = [
+        "/usr/bin/env",
+        "python3.7",
+        repository_ctx.path(repository_ctx.attr._script),
+        "--whl",
+        repository_ctx.path(repository_ctx.attr.whl),
+        "--requirements",
+        repository_ctx.attr.requirements,
     ]
 
-  result = repository_ctx.execute(args)
-  if result.return_code:
-    fail("whl_library failed: %s (%s)" % (result.stdout, result.stderr))
+    if repository_ctx.attr.extras:
+        args += [
+            "--extras=%s" % extra
+            for extra in repository_ctx.attr.extras
+        ]
+
+    result = repository_ctx.execute(args)
+    if result.return_code:
+        fail("whl_library failed: %s (%s)" % (result.stdout, result.stderr))
 
 whl_library = repository_rule(
     attrs = {
diff --git a/rules_python/whl.py b/rules_python/whl.py
index 3e9d4f88fa..8ac0601d86 100644
--- a/rules_python/whl.py
+++ b/rules_python/whl.py
@@ -14,12 +14,17 @@
 """The whl modules defines classes for interacting with Python packages."""
 
 import argparse
+import collections
+import email.parser
 import json
 import os
 import pkg_resources
 import re
 import zipfile
 
+EXTRA_RE = re.compile("""^(?P<package>.*?)(;\s*(?P<condition>.*?)(extra == '(?P<extra>.*?)')?)$""")
+MayRequiresKey = collections.namedtuple('MayRequiresKey', ('condition', 'extra'))
+
 
 class Wheel(object):
 
@@ -107,9 +112,43 @@ def expand(self, directory):
 
   # _parse_metadata parses METADATA files according to https://www.python.org/dev/peps/pep-0314/
   def _parse_metadata(self, content):
-    # TODO: handle fields other than just name
-    name_pattern = re.compile('Name: (.*)')
-    return { 'name': name_pattern.search(content).group(1) }
+    metadata = {}
+    pkg_info = email.parser.Parser().parsestr(content)
+    metadata['name'] = pkg_info.get('Name')
+    extras = pkg_info.get_all('Provides-Extra')
+    if extras:
+      metadata['extras'] = list(set(extras))
+
+    reqs_dist = pkg_info.get_all('Requires-Dist') or []
+    requires = collections.defaultdict(set)
+    for value in sorted(reqs_dist):
+      extra_match = EXTRA_RE.search(value)
+      if extra_match:
+        groupdict = extra_match.groupdict()
+        condition = groupdict['condition']
+        extra = groupdict['extra']
+        package = groupdict['package']
+        if condition.endswith(' and '):
+          condition = condition[:-5]
+      else:
+        condition, extra = None, None
+        package = value
+      key = MayRequiresKey(condition, extra)
+      requires[key].add(package)
+
+    if requires:
+      metadata['run_requires'] = []
+      for key, value in requires.items():
+        requirement = {
+          'requires': list(value)
+        }
+        if key.extra:
+          requirement['extra'] = key.extra
+        if key.condition:
+          requirement['environment'] = key.condition
+        metadata['run_requires'].append(requirement)
+
+    return metadata
 
 
 parser = argparse.ArgumentParser(
diff --git a/tools/piptool.par b/tools/piptool.par
index 11ec453cd7..8b6b74dd7c 100755
Binary files a/tools/piptool.par and b/tools/piptool.par differ
diff --git a/tools/update_tools/Dockerfile b/tools/update_tools/Dockerfile
index 4439eb810c..41e6e8c37d 100644
--- a/tools/update_tools/Dockerfile
+++ b/tools/update_tools/Dockerfile
@@ -1,14 +1,15 @@
-FROM gcr.io/gcp-runtimes/ubuntu_16_0_4:latest
+FROM ubuntu:18.04
 
 # Install Bazel (https://docs.bazel.build/versions/master/install-ubuntu.html)
-RUN apt-get update -y && apt-get install openjdk-8-jdk -y
+RUN apt-get update -y && apt-get install openjdk-8-jdk curl gnupg -y
 RUN echo "deb [arch=amd64] http://storage.googleapis.com/bazel-apt stable jdk1.8" | tee /etc/apt/sources.list.d/bazel.list
 RUN curl https://bazel.build/bazel-release.pub.gpg | apt-key add -
 RUN apt-get update -y && apt-get install bazel -y
 RUN bazel help info >/dev/null 2>&1
 
-# Install Python 2.7.12
-RUN apt-get install python -y
+# Install Python 3.7
+RUN apt-get install python3.7 python3.7-distutils -y
+RUN ln -s /usr/bin/python3.7 /usr/bin/python
 
 # Build par files.  We have a source and work directory to avoid
 # stomping on other files as root.
diff --git a/tools/whltool.par b/tools/whltool.par
index 7cb59c0fbe..dce6f44101 100755
Binary files a/tools/whltool.par and b/tools/whltool.par differ
diff --git a/update_tools.sh b/update_tools.sh
index 24a655e392..748c9b7e98 100755
--- a/update_tools.sh
+++ b/update_tools.sh
@@ -22,7 +22,7 @@ usage() {
 }
 
 if [ "$#" -eq 0 ] ; then
-  docker build --no-cache -f tools/update_tools/Dockerfile --tag rules_python:update_tools .
+  docker build -f tools/update_tools/Dockerfile --tag rules_python:update_tools .
   docker run -v"$PWD":/opt/rules_python_source rules_python:update_tools
 elif [ "$#" -eq 1 -a "$1" == "--nodocker" ] ; then
   bazel build //rules_python:piptool.par //rules_python:whltool.par